Merge branch 'master' into tmp-path

Conflicts:
	plugins/Installation/SystemCheck.php

41 files changed, 1574 insertions, 810 deletions

diff --git a/core/API/DataTableGenericFilter.php b/core/API/DataTableGenericFilter.php
index 681c1a12f8..46274b0c31 100644
--- a/core/API/DataTableGenericFilter.php
+++ b/core/API/DataTableGenericFilter.php
@@ -12,6 +12,8 @@ use Exception;
 use Piwik\Common;
 use Piwik\DataTable\Filter\AddColumnsProcessedMetricsGoal;
 use Piwik\DataTable;
+use Piwik\Plugin\ProcessedMetric;
+use Piwik\Plugin\Report;
 
 class DataTableGenericFilter
 {
@@ -82,15 +84,6 @@ class DataTableGenericFilter
                       'filter_excludelowpop'       => array('string'),
                       'filter_excludelowpop_value' => array('float', '0'),
                   )),
-            array('AddColumnsProcessedMetrics',
-                  array(
-                      'filter_add_columns_when_show_all_columns' => array('integer')
-                  )),
-            array('AddColumnsProcessedMetricsGoal',
-                  array(
-                      'filter_update_columns_when_show_all_goals' => array('integer'),
-                      'idGoal'                                    => array('string', AddColumnsProcessedMetricsGoal::GOALS_OVERVIEW),
-                  )),
             array('Sort',
                   array(
                       'filter_sort_column' => array('string'),
@@ -105,7 +98,7 @@ class DataTableGenericFilter
                       'filter_offset'    => array('integer', '0'),
                       'filter_limit'     => array('integer'),
                       'keep_summary_row' => array('integer', '0'),
-                  )),
+                  ))
         );
     }
 
@@ -164,6 +157,45 @@ class DataTableGenericFilter
                 $filterApplied = true;
             }
         }
+
         return $filterApplied;
     }
-}
+
+    public function areProcessedMetricsNeededFor($metrics)
+    {
+        $columnQueryParameters = array(
+            'filter_column',
+            'filter_column_recursive',
+            'filter_excludelowpop',
+            'filter_sort_column'
+        );
+
+        foreach ($columnQueryParameters as $queryParamName) {
+            $queryParamValue = Common::getRequestVar($queryParamName, false, $type = null, $this->request);
+            if (!empty($queryParamValue)
+                && $this->containsProcessedMetric($metrics, $queryParamValue)
+            ) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * @param ProcessedMetric[] $metrics
+     * @param string $name
+     * @return bool
+     */
+    private function containsProcessedMetric($metrics, $name)
+    {
+        foreach ($metrics as $metric) {
+            if ($metric instanceof ProcessedMetric
+                && $metric->getName() == $name
+            ) {
+                return true;
+            }
+        }
+        return false;
+    }
+}
\ No newline at end of file
diff --git a/core/API/DataTableManipulator.php b/core/API/DataTableManipulator.php
index 6d744e50df..a1acc6e5b5 100644
--- a/core/API/DataTableManipulator.php
+++ b/core/API/DataTableManipulator.php
@@ -172,6 +172,8 @@ abstract class DataTableManipulator
         $request = $this->manipulateSubtableRequest($request);
         $request['serialize'] = 0;
         $request['expanded'] = 0;
+        $request['format'] = 'original';
+        $request['format_metrics'] = 0;
 
         // don't want to run recursive filters on the subtables as they are loaded,
         // otherwise the result will be empty in places (or everywhere). instead we
@@ -181,14 +183,7 @@ abstract class DataTableManipulator
         $dataTable = Proxy::getInstance()->call($class, $method, $request);
         $response = new ResponseBuilder($format = 'original', $request);
         $response->disableSendHeader();
-        $dataTable = $response->getResponse($dataTable);
-
-        if (Common::getRequestVar('disable_queued_filters', 0, 'int', $request) == 0) {
-            if (method_exists($dataTable, 'applyQueuedFilters')) {
-                $dataTable->applyQueuedFilters();
-            }
-        }
-
+        $dataTable = $response->getResponse($dataTable, $apiModule, $method);
         return $dataTable;
     }
 }
diff --git a/core/API/DataTableManipulator/ReportTotalsCalculator.php b/core/API/DataTableManipulator/ReportTotalsCalculator.php
index 1cbfeeb362..b6b82effad 100644
--- a/core/API/DataTableManipulator/ReportTotalsCalculator.php
+++ b/core/API/DataTableManipulator/ReportTotalsCalculator.php
@@ -13,7 +13,7 @@ use Piwik\DataTable;
 use Piwik\DataTable\Row;
 use Piwik\Metrics;
 use Piwik\Period;
-use Piwik\Plugins\API\API;
+use Piwik\Plugin\Report;
 
 /**
  * This class is responsible for setting the metadata property 'totals' on each dataTable if the report
@@ -23,12 +23,6 @@ use Piwik\Plugins\API\API;
 class ReportTotalsCalculator extends DataTableManipulator
 {
     /**
-     * Cached report metadata array.
-     * @var array
-     */
-    private static $reportMetadata = array();
-
-    /**
      * @param  DataTable $table
      * @return \Piwik\DataTable|\Piwik\DataTable\Map
      */
@@ -61,7 +55,7 @@ class ReportTotalsCalculator extends DataTableManipulator
     {
         $report = $this->findCurrentReport();
 
-        if (!empty($report) && empty($report['dimension'])) {
+        if (!empty($report) && !$report->getDimension() && !$this->isReportAllMetricsReport($report)) {
             // we currently do not calculate the total value for reports having no dimension
             return $dataTable;
         }
@@ -73,12 +67,13 @@ class ReportTotalsCalculator extends DataTableManipulator
         $metricsToCalculate = Metrics::getMetricIdsToProcessReportTotal();
 
         foreach ($metricsToCalculate as $metricId) {
-            if (!$this->hasDataTableMetric($firstLevelTable, $metricId)) {
+            $realMetricName = $this->hasDataTableMetric($firstLevelTable, $metricId);
+            if (empty($realMetricName)) {
                 continue;
             }
 
             foreach ($firstLevelTable->getRows() as $row) {
-                $totalValues = $this->sumColumnValueToTotal($row, $metricId, $totalValues);
+                $totalValues = $this->sumColumnValueToTotal($row, $metricId, $realMetricName, $totalValues);
             }
         }
 
@@ -95,34 +90,20 @@ class ReportTotalsCalculator extends DataTableManipulator
             return false;
         }
 
-        if (false === $this->getColumn($firstRow, $metricId)) {
-            return false;
-        }
-
-        return true;
-    }
-
-    /**
-     * Returns column from a given row.
-     * Will work with 2 types of datatable
-     * - raw datatables coming from the archive DB, which columns are int indexed
-     * - datatables processed resulting of API calls, which columns have human readable english names
-     *
-     * @param Row|array $row
-     * @param int $columnIdRaw see consts in Metrics::
-     * @return mixed  Value of column, false if not found
-     */
-    private function getColumn($row, $columnIdRaw)
-    {
-        $columnIdReadable = Metrics::getReadableColumnName($columnIdRaw);
+        $readableColumnName = Metrics::getReadableColumnName($metricId);
+        $columnAlternatives = array(
+            $metricId,
+            $readableColumnName,
+            // TODO: this and below is a hack to get report totals to work correctly w/ MultiSites.getAll. can be corrected
+            //       when all metrics are described by Metadata classes & internal naming quirks are handled by core system.
+            'Goal_' . $readableColumnName,
+            'Actions_' . $readableColumnName
+        );
 
-        if ($row instanceof Row) {
-            $raw = $row->getColumn($columnIdRaw);
-            if ($raw !== false) {
-                return $raw;
+        foreach ($columnAlternatives as $column) {
+            if ($firstRow->getColumn($column) !== false) {
+                return $column;
             }
-
-            return $row->getColumn($columnIdReadable);
         }
 
         return false;
@@ -141,8 +122,8 @@ class ReportTotalsCalculator extends DataTableManipulator
             $module = $this->apiModule;
             $action = $this->apiMethod;
         } else {
-            $module = $firstLevelReport['module'];
-            $action = $firstLevelReport['action'];
+            $module = $firstLevelReport->getModule();
+            $action = $firstLevelReport->getAction();
         }
 
         $request = $this->request;
@@ -170,9 +151,9 @@ class ReportTotalsCalculator extends DataTableManipulator
         return $table;
     }
 
-    private function sumColumnValueToTotal(Row $row, $metricId, $totalValues)
+    private function sumColumnValueToTotal(Row $row, $metricId, $realMetricId, $totalValues)
     {
-        $value = $this->getColumn($row, $metricId);
+        $value = $row->getColumn($realMetricId);
 
         if (false === $value) {
 
@@ -217,38 +198,26 @@ class ReportTotalsCalculator extends DataTableManipulator
         return $request;
     }
 
-    private function getReportMetadata()
-    {
-        if (!empty(static::$reportMetadata)) {
-            return static::$reportMetadata;
-        }
-
-        static::$reportMetadata = API::getInstance()->getReportMetadata();
-
-        return static::$reportMetadata;
-    }
-
     private function findCurrentReport()
     {
-        foreach ($this->getReportMetadata() as $report) {
-            if ($this->apiMethod == $report['action']
-                && $this->apiModule == $report['module']) {
-
-                return $report;
-            }
-        }
+        return Report::factory($this->apiModule, $this->apiMethod);
     }
 
     private function findFirstLevelReport()
     {
-        foreach ($this->getReportMetadata() as $report) {
-            if (!empty($report['actionToLoadSubTables'])
-                && $this->apiMethod == $report['actionToLoadSubTables']
-                && $this->apiModule == $report['module']
+        foreach (Report::getAllReports() as $report) {
+            $actionToLoadSubtables = $report->getActionToLoadSubTables();
+            if ($actionToLoadSubtables == $this->apiMethod
+                && $this->apiModule == $report->getModule()
             ) {
-
                 return $report;
             }
         }
+        return null;
+    }
+
+    private function isReportAllMetricsReport(Report $report)
+    {
+        return $report->getModule() == 'API' && $report->getAction() == 'get';
     }
 }
diff --git a/core/API/DataTablePostProcessor.php b/core/API/DataTablePostProcessor.php
new file mode 100644
index 0000000000..72facbf41c
--- /dev/null
+++ b/core/API/DataTablePostProcessor.php
@@ -0,0 +1,391 @@
+<?php
+/**
+ * Piwik - free/libre analytics platform
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ */
+
+namespace Piwik\API;
+
+use Exception;
+use Piwik\API\DataTableManipulator\Flattener;
+use Piwik\API\DataTableManipulator\LabelFilter;
+use Piwik\API\DataTableManipulator\ReportTotalsCalculator;
+use Piwik\Common;
+use Piwik\DataTable;
+use Piwik\DataTable\DataTableInterface;
+use Piwik\DataTable\Filter\PivotByDimension;
+use Piwik\Metrics\Formatter;
+use Piwik\Plugin\ProcessedMetric;
+use Piwik\Plugin\Report;
+
+/**
+ * Processes DataTables that should be served through Piwik's APIs. This processing handles
+ * special query parameters and computes processed metrics. It does not included rendering to
+ * output formats (eg, 'xml').
+ */
+class DataTablePostProcessor
+{
+    const PROCESSED_METRICS_COMPUTED_FLAG = 'processed_metrics_computed';
+
+    /**
+     * @var null|Report
+     */
+    private $report;
+
+    /**
+     * @var string[]
+     */
+    private $request;
+
+    /**
+     * @var string
+     */
+    private $apiModule;
+
+    /**
+     * @var string
+     */
+    private $apiMethod;
+
+    /**
+     * @var Inconsistencies
+     */
+    private $apiInconsistencies;
+
+    /**
+     * @var Formatter
+     */
+    private $formatter;
+
+    /**
+     * Constructor.
+     */
+    public function __construct($apiModule, $apiMethod, $request)
+    {
+        $this->apiModule = $apiModule;
+        $this->apiMethod = $apiMethod;
+        $this->request = $request;
+
+        $this->report = Report::factory($apiModule, $apiMethod);
+        $this->apiInconsistencies = new Inconsistencies();
+        $this->formatter = new Formatter();
+    }
+
+    /**
+     * Apply post-processing logic to a DataTable of a report for an API request.
+     *
+     * @param DataTableInterface $dataTable The data table to process.
+     * @return DataTableInterface A new data table.
+     */
+    public function process(DataTableInterface $dataTable)
+    {
+        // TODO: when calculating metrics before hand, only calculate for needed metrics, not all. NOTE:
+        //       this is non-trivial since it will require, eg, to make sure processed metrics aren't added
+        //       after pivotBy is handled.
+        $dataTable = $this->applyPivotByFilter($dataTable);
+        $dataTable = $this->applyFlattener($dataTable);
+        $dataTable = $this->applyTotalsCalculator($dataTable);
+
+        $dataTable = $this->applyGenericFilters($dataTable);
+
+        $this->applyComputeProcessedMetrics($dataTable);
+
+        // we automatically safe decode all datatable labels (against xss)
+        $dataTable->queueFilter('SafeDecodeLabel');
+
+        $dataTable = $this->applyQueuedFilters($dataTable);
+        $dataTable = $this->applyRequestedColumnDeletion($dataTable);
+        $dataTable = $this->applyLabelFilter($dataTable);
+
+        $dataTable = $this->applyMetricsFormatting($dataTable, null);
+
+        return $dataTable;
+    }
+
+    /**
+     * @param DataTableInterface $dataTable
+     * @return DataTableInterface
+     */
+    public function applyPivotByFilter(DataTableInterface $dataTable)
+    {
+        $pivotBy = Common::getRequestVar('pivotBy', false, 'string', $this->request);
+        if (!empty($pivotBy)) {
+            $this->applyComputeProcessedMetrics($dataTable);
+
+            $reportId = $this->apiModule . '.' . $this->apiMethod;
+            $pivotByColumn = Common::getRequestVar('pivotByColumn', false, 'string', $this->request);
+            $pivotByColumnLimit = Common::getRequestVar('pivotByColumnLimit', false, 'int', $this->request);
+
+            $dataTable->filter('PivotByDimension', array($reportId, $pivotBy, $pivotByColumn, $pivotByColumnLimit,
+                PivotByDimension::isSegmentFetchingEnabledInConfig()));
+        }
+        return $dataTable;
+    }
+
+    /**
+     * @param DataTableInterface $dataTable
+     * @return DataTable|DataTableInterface|DataTable\Map
+     */
+    public function applyFlattener($dataTable)
+    {
+        if (Common::getRequestVar('flat', '0', 'string', $this->request) == '1') {
+            $flattener = new Flattener($this->apiModule, $this->apiMethod, $this->request);
+            if (Common::getRequestVar('include_aggregate_rows', '0', 'string', $this->request) == '1') {
+                $flattener->includeAggregateRows();
+            }
+            $dataTable = $flattener->flatten($dataTable);
+        }
+        return $dataTable;
+    }
+
+    /**
+     * @param DataTableInterface $dataTable
+     * @return DataTableInterface
+     */
+    public function applyTotalsCalculator($dataTable)
+    {
+        if (1 == Common::getRequestVar('totals', '1', 'integer', $this->request)) {
+            $reportTotalsCalculator = new ReportTotalsCalculator($this->apiModule, $this->apiMethod, $this->request);
+            $dataTable     = $reportTotalsCalculator->calculate($dataTable);
+        }
+        return $dataTable;
+    }
+
+    /**
+     * @param DataTableInterface $dataTable
+     * @return DataTableInterface
+     */
+    public function applyGenericFilters($dataTable)
+    {
+        // if the flag disable_generic_filters is defined we skip the generic filters
+        if (0 == Common::getRequestVar('disable_generic_filters', '0', 'string', $this->request)) {
+            $this->applyProcessedMetricsGenericFilters($dataTable);
+
+            $genericFilter = new DataTableGenericFilter($this->request);
+
+            $self = $this;
+            $report = $this->report;
+            $dataTable->filter(function (DataTable $table) use ($genericFilter, $report, $self) {
+                $processedMetrics = Report::getProcessedMetricsForTable($table, $report);
+                if ($genericFilter->areProcessedMetricsNeededFor($processedMetrics)) {
+                    $self->computeProcessedMetrics($table);
+                }
+            });
+
+            $label = self::getLabelFromRequest($this->request);
+            if (!empty($label)) {
+                $genericFilter->disableFilters(array('Limit', 'Truncate'));
+            }
+
+            $genericFilter->filter($dataTable);
+        }
+
+        return $dataTable;
+    }
+
+    /**
+     * @param DataTableInterface $dataTable
+     * @return DataTableInterface
+     */
+    public function applyProcessedMetricsGenericFilters($dataTable)
+    {
+        $addNormalProcessedMetrics = null;
+        try {
+            $addNormalProcessedMetrics = Common::getRequestVar(
+                'filter_add_columns_when_show_all_columns', null, 'integer', $this->request);
+        } catch (Exception $ex) {
+            // ignore
+        }
+
+        if ($addNormalProcessedMetrics !== null) {
+            $dataTable->filter('AddColumnsProcessedMetrics', array($addNormalProcessedMetrics));
+        }
+
+        $addGoalProcessedMetrics = null;
+        try {
+            $addGoalProcessedMetrics = Common::getRequestVar(
+                'filter_update_columns_when_show_all_goals', null, 'integer', $this->request);
+        } catch (Exception $ex) {
+            // ignore
+        }
+
+        if ($addGoalProcessedMetrics !== null) {
+            $idGoal = Common::getRequestVar(
+                'idGoal', DataTable\Filter\AddColumnsProcessedMetricsGoal::GOALS_OVERVIEW, 'string', $this->request);
+
+            $dataTable->filter('AddColumnsProcessedMetricsGoal', array($ignore = true, $idGoal));
+        }
+
+        return $dataTable;
+    }
+
+    /**
+     * @param DataTableInterface $dataTable
+     * @return DataTableInterface
+     */
+    public function applyQueuedFilters($dataTable)
+    {
+        // if the flag disable_queued_filters is defined we skip the filters that were queued
+        if (Common::getRequestVar('disable_queued_filters', 0, 'int', $this->request) == 0) {
+            $dataTable->applyQueuedFilters();
+        }
+        return $dataTable;
+    }
+
+    /**
+     * @param DataTableInterface $dataTable
+     * @return DataTableInterface
+     */
+    public function applyRequestedColumnDeletion($dataTable)
+    {
+        // use the ColumnDelete filter if hideColumns/showColumns is provided (must be done
+        // after queued filters are run so processed metrics can be removed, too)
+        $hideColumns = Common::getRequestVar('hideColumns', '', 'string', $this->request);
+        $showColumns = Common::getRequestVar('showColumns', '', 'string', $this->request);
+        if (!empty($hideColumns)
+            || !empty($showColumns)
+        ) {
+            $dataTable->filter('ColumnDelete', array($hideColumns, $showColumns));
+        } else {
+            $this->removeTemporaryMetrics($dataTable);
+        }
+
+        return $dataTable;
+    }
+
+    /**
+     * @param DataTableInterface $dataTable
+     */
+    public function removeTemporaryMetrics(DataTableInterface $dataTable)
+    {
+        $allColumns = !empty($this->report) ? $this->report->getAllMetrics() : array();
+
+        $report = $this->report;
+        $dataTable->filter(function (DataTable $table) use ($report, $allColumns) {
+            $processedMetrics = Report::getProcessedMetricsForTable($table, $report);
+
+            $allTemporaryMetrics = array();
+            foreach ($processedMetrics as $metric) {
+                $allTemporaryMetrics = array_merge($allTemporaryMetrics, $metric->getTemporaryMetrics());
+            }
+
+            if (!empty($allTemporaryMetrics)) {
+                $table->filter('ColumnDelete', array($allTemporaryMetrics));
+            }
+        });
+    }
+
+    /**
+     * @param DataTableInterface $dataTable
+     * @return DataTableInterface
+     */
+    public function applyLabelFilter($dataTable)
+    {
+        $label = self::getLabelFromRequest($this->request);
+
+        // apply label filter: only return rows matching the label parameter (more than one if more than one label)
+        if (!empty($label)) {
+            $addLabelIndex = Common::getRequestVar('labelFilterAddLabelIndex', 0, 'int', $this->request) == 1;
+
+            $filter = new LabelFilter($this->apiModule, $this->apiMethod, $this->request);
+            $dataTable = $filter->filter($label, $dataTable, $addLabelIndex);
+        }
+        return $dataTable;
+    }
+
+    /**
+     * @param DataTableInterface $dataTable
+     * @return DataTableInterface
+     */
+    public function applyMetricsFormatting($dataTable)
+    {
+        $formatMetrics = Common::getRequestVar('format_metrics', 0, 'string', $this->request);
+        if ($formatMetrics == '0') {
+            return $dataTable;
+        }
+
+        // in Piwik 2.X & below, metrics are not formatted in API responses except for percents.
+        // this code implements this inconsistency
+        $onlyFormatPercents = $formatMetrics === 'bc';
+
+        $metricsToFormat = null;
+        if ($onlyFormatPercents) {
+            $metricsToFormat = $this->apiInconsistencies->getPercentMetricsToFormat();
+        }
+
+        $dataTable->filter(array($this->formatter, 'formatMetrics'), array($this->report, $metricsToFormat));
+        return $dataTable;
+    }
+
+    /**
+     * Returns the value for the label query parameter which can be either a string
+     * (ie, label=...) or array (ie, label[]=...).
+     *
+     * @param array $request
+     * @return array
+     */
+    public static function getLabelFromRequest($request)
+    {
+        $label = Common::getRequestVar('label', array(), 'array', $request);
+        if (empty($label)) {
+            $label = Common::getRequestVar('label', '', 'string', $request);
+            if (!empty($label)) {
+                $label = array($label);
+            }
+        }
+
+        $label = self::unsanitizeLabelParameter($label);
+        return $label;
+    }
+
+    public static function unsanitizeLabelParameter($label)
+    {
+        // this is needed because Proxy uses Common::getRequestVar which in turn
+        // uses Common::sanitizeInputValue. This causes the > that separates recursive labels
+        // to become &gt; and we need to undo that here.
+        $label = Common::unsanitizeInputValues($label);
+        return $label;
+    }
+
+    public function computeProcessedMetrics(DataTable $dataTable)
+    {
+        if ($dataTable->getMetadata(self::PROCESSED_METRICS_COMPUTED_FLAG)) {
+            return;
+        }
+
+        /** @var ProcessedMetric[] $processedMetrics */
+        $processedMetrics = Report::getProcessedMetricsForTable($dataTable, $this->report);
+        if (empty($processedMetrics)) {
+            return;
+        }
+
+        $dataTable->setMetadata(self::PROCESSED_METRICS_COMPUTED_FLAG, true);
+
+        foreach ($processedMetrics as $name => $processedMetric) {
+            if (!$processedMetric->beforeCompute($this->report, $dataTable)) {
+                continue;
+            }
+
+            foreach ($dataTable->getRows() as $row) {
+                if ($row->getColumn($name) === false) { // only compute the metric if it has not been computed already
+                    $computedValue = $processedMetric->compute($row);
+                    if ($computedValue !== false) {
+                        $row->addColumn($name, $computedValue);
+                    }
+
+                    $subtable = $row->getSubtable();
+                    if (!empty($subtable)) {
+                        $this->computeProcessedMetrics($subtable);
+                    }
+                }
+            }
+        }
+    }
+
+    public function applyComputeProcessedMetrics(DataTableInterface $dataTable)
+    {
+        $dataTable->filter(array($this, 'computeProcessedMetrics'));
+    }
+}
\ No newline at end of file
diff --git a/core/API/DocumentationGenerator.php b/core/API/DocumentationGenerator.php
index 6a140ac8fb..3c88f62027 100644
--- a/core/API/DocumentationGenerator.php
+++ b/core/API/DocumentationGenerator.php
@@ -132,13 +132,13 @@ class DocumentationGenerator
             $lastNUrls = '';
             if (preg_match('/(&period)|(&date)/', $exampleUrl)) {
                 $exampleUrlRss = $prefixUrls . $this->getExampleUrl($class, $methodName, array('date' => 'last10', 'period' => 'day') + $parametersToSet);
-                $lastNUrls = ", RSS of the last <a target=_blank href='$exampleUrlRss&format=rss$token_auth&translateColumnNames=1'>10 days</a>";
+                $lastNUrls = ", RSS of the last <a target='_blank' href='$exampleUrlRss&format=rss$token_auth&translateColumnNames=1'>10 days</a>";
             }
             $exampleUrl = $prefixUrls . $exampleUrl;
             $str .= " [ Example in
-                                                                    <a target=_blank href='$exampleUrl&format=xml$token_auth'>XML</a>,
-                                                                    <a target=_blank href='$exampleUrl&format=JSON$token_auth'>Json</a>,
-                                                                    <a target=_blank href='$exampleUrl&format=Tsv$token_auth&translateColumnNames=1'>Tsv (Excel)</a>
+                                                                    <a target='_blank' href='$exampleUrl&format=xml$token_auth'>XML</a>,
+                                                                    <a target='_blank' href='$exampleUrl&format=JSON$token_auth'>Json</a>,
+                                                                    <a target='_blank' href='$exampleUrl&format=Tsv$token_auth&translateColumnNames=1'>Tsv (Excel)</a>
                                                                     $lastNUrls
                                                                     ]";
         } else {
@@ -350,13 +350,13 @@ class DocumentationGenerator
                 $lastNUrls = '';
                 if (preg_match('/(&period)|(&date)/', $exampleUrl)) {
                     $exampleUrlRss = $prefixUrls . $this->getExampleUrl($class, $methodName, array('date' => 'last10', 'period' => 'day') + $parametersToSet);
-                    $lastNUrls = ",	RSS of the last <a target=_blank href='$exampleUrlRss&format=rss$token_auth&translateColumnNames=1'>10 days</a>";
+                    $lastNUrls = ",	RSS of the last <a target='_blank' href='$exampleUrlRss&format=rss$token_auth&translateColumnNames=1'>10 days</a>";
                 }
                 $exampleUrl = $prefixUrls . $exampleUrl;
                 $str .= " [ Example in
-									<a target=_blank href='$exampleUrl&format=xml$token_auth'>XML</a>,
-									<a target=_blank href='$exampleUrl&format=JSON$token_auth'>Json</a>,
-									<a target=_blank href='$exampleUrl&format=Tsv$token_auth&translateColumnNames=1'>Tsv (Excel)</a>
+									<a target='_blank' href='$exampleUrl&format=xml$token_auth'>XML</a>,
+									<a target='_blank' href='$exampleUrl&format=JSON$token_auth'>Json</a>,
+									<a target='_blank' href='$exampleUrl&format=Tsv$token_auth&translateColumnNames=1'>Tsv (Excel)</a>
 									$lastNUrls
 									]";
             } else {
diff --git a/core/API/Inconsistencies.php b/core/API/Inconsistencies.php
new file mode 100644
index 0000000000..5d0c20d418
--- /dev/null
+++ b/core/API/Inconsistencies.php
@@ -0,0 +1,42 @@
+<?php
+/**
+ * Piwik - free/libre analytics platform
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ */
+namespace Piwik\API;
+
+/**
+ * Contains logic to replicate inconsistencies in Piwik's API. This class exists
+ * to provide a way to clean up existing Piwik code and behavior without breaking
+ * backwards compatibility immediately.
+ *
+ * Code that handles the case when the 'format_metrics' query parameter value is
+ * 'bc' should be removed as well. This code is in API\Request and DataTablePostProcessor.
+ *
+ * Should be removed before releasing Piwik 3.0.
+ */
+class Inconsistencies
+{
+    /**
+     * In Piwik 2.X and below, the "raw" API would format percent values but no others.
+     * This method returns the list of percent metrics that were returned from the API
+     * formatted so we can maintain BC.
+     *
+     * Used by DataTablePostProcessor.
+     */
+    public function getPercentMetricsToFormat()
+    {
+        return array(
+            'bounce_rate',
+            'conversion_rate',
+            'interaction_rate',
+            'exit_rate',
+            'bounce_rate_returning',
+            'nb_visits_percentage',
+            '/.*_evolution/',
+            '/goal_.*_conversion_rate/'
+        );
+    }
+}
\ No newline at end of file
diff --git a/core/API/Request.php b/core/API/Request.php
index 64e8e054fa..979f1299d0 100644
--- a/core/API/Request.php
+++ b/core/API/Request.php
@@ -79,15 +79,23 @@ class Request
      *
      * @param string|array $request The base request string or array, eg,
      *                              `'module=UserSettings&action=getWidescreen'`.
+     * @param array $defaultRequest Default query parameters. If a query parameter is absent in `$request`, it will be loaded
+     *                              from this. Defaults to `$_GET + $_POST`.
      * @return array
      */
-    public static function getRequestArrayFromString($request)
+    public static function getRequestArrayFromString($request, $defaultRequest = null)
     {
-        $defaultRequest = $_GET + $_POST;
+        if ($defaultRequest === null) {
+            $defaultRequest = $_GET + $_POST;
 
-        $requestRaw = self::getRequestParametersGET();
-        if (!empty($requestRaw['segment'])) {
-            $defaultRequest['segment'] = $requestRaw['segment'];
+            $requestRaw = self::getRequestParametersGET();
+            if (!empty($requestRaw['segment'])) {
+                $defaultRequest['segment'] = $requestRaw['segment'];
+            }
+
+            if (empty($defaultRequest['format_metrics'])) {
+                $defaultRequest['format_metrics'] = 'bc';
+            }
         }
 
         $requestArray = $defaultRequest;
@@ -120,10 +128,12 @@ class Request
      *                              eg, `'method=UserSettings.getWideScreen&idSite=1&date=yesterday&period=week&format=xml'`
      *                              If a request is not provided, then we use the values in the `$_GET` and `$_POST`
      *                              superglobals.
+     * @param array $defaultRequest Default query parameters. If a query parameter is absent in `$request`, it will be loaded
+     *                              from this. Defaults to `$_GET + $_POST`.
      */
-    public function __construct($request = null)
+    public function __construct($request = null, $defaultRequest = null)
     {
-        $this->request = self::getRequestArrayFromString($request);
+        $this->request = self::getRequestArrayFromString($request, $defaultRequest);
         $this->sanitizeRequest();
     }
 
@@ -289,9 +299,13 @@ class Request
      * @param string $method The API method to call, ie, `'Actions.getPageTitles'`.
      * @param array $paramOverride The parameter name-value pairs to use instead of what's
      *                             in `$_GET` & `$_POST`.
+     * @param array $defaultRequest Default query parameters. If a query parameter is absent in `$request`, it will be loaded
+     *                              from this. Defaults to `$_GET + $_POST`.
+     *
+     *                              To avoid using any parameters from $_GET or $_POST, set this to an empty `array()`.
      * @return mixed The result of the API request. See {@link process()}.
      */
-    public static function processRequest($method, $paramOverride = array())
+    public static function processRequest($method, $paramOverride = array(), $defaultRequest = null)
     {
         $params = array();
         $params['format'] = 'original';
@@ -300,7 +314,7 @@ class Request
         $params = $paramOverride + $params;
 
         // process request
-        $request = new Request($params);
+        $request = new Request($params, $defaultRequest);
         return $request->process();
     }
 
diff --git a/core/API/ResponseBuilder.php b/core/API/ResponseBuilder.php
index 5b00c01a13..4ebe50305d 100644
--- a/core/API/ResponseBuilder.php
+++ b/core/API/ResponseBuilder.php
@@ -9,15 +9,13 @@
 namespace Piwik\API;
 
 use Exception;
-use Piwik\API\DataTableManipulator\Flattener;
-use Piwik\API\DataTableManipulator\LabelFilter;
-use Piwik\API\DataTableManipulator\ReportTotalsCalculator;
 use Piwik\Common;
 use Piwik\DataTable;
-use Piwik\DataTable\Filter\PivotByDimension;
 use Piwik\DataTable\Renderer;
 use Piwik\DataTable\DataTableInterface;
 use Piwik\DataTable\Filter\ColumnDelete;
+use Piwik\Plugin\Report;
+use Piwik\Plugins\API\Renderer\Original;
 
 /**
  */
@@ -166,66 +164,8 @@ class ResponseBuilder
 
     private function handleDataTable(DataTableInterface $datatable)
     {
-        $label = $this->getLabelFromRequest($this->request);
-
-        // handle pivot by dimension filter
-        $pivotBy = Common::getRequestVar('pivotBy', false, 'string', $this->request);
-        if (!empty($pivotBy)) {
-            $reportId = $this->apiModule . '.' . $this->apiMethod;
-            $pivotByColumn = Common::getRequestVar('pivotByColumn', false, 'string', $this->request);
-            $pivotByColumnLimit = Common::getRequestVar('pivotByColumnLimit', false, 'int', $this->request);
-
-            $datatable->filter('PivotByDimension', array($reportId, $pivotBy, $pivotByColumn, $pivotByColumnLimit,
-                PivotByDimension::isSegmentFetchingEnabledInConfig()));
-        }
-
-        // if requested, flatten nested tables
-        if (Common::getRequestVar('flat', '0', 'string', $this->request) == '1') {
-            $flattener = new Flattener($this->apiModule, $this->apiMethod, $this->request);
-            if (Common::getRequestVar('include_aggregate_rows', '0', 'string', $this->request) == '1') {
-                $flattener->includeAggregateRows();
-            }
-            $datatable = $flattener->flatten($datatable);
-        }
-
-        if (1 == Common::getRequestVar('totals', '1', 'integer', $this->request)) {
-            $genericFilter = new ReportTotalsCalculator($this->apiModule, $this->apiMethod, $this->request);
-            $datatable     = $genericFilter->calculate($datatable);
-        }
-
-        // if the flag disable_generic_filters is defined we skip the generic filters
-        if (0 == Common::getRequestVar('disable_generic_filters', '0', 'string', $this->request)) {
-            $genericFilter = new DataTableGenericFilter($this->request);
-            if (!empty($label)) {
-                $genericFilter->disableFilters(array('Limit', 'Truncate'));
-            }
-
-            $genericFilter->filter($datatable);
-        }
-
-        // we automatically safe decode all datatable labels (against xss)
-        $datatable->queueFilter('SafeDecodeLabel');
-
-        // if the flag disable_queued_filters is defined we skip the filters that were queued
-        if (Common::getRequestVar('disable_queued_filters', 0, 'int', $this->request) == 0) {
-            $datatable->applyQueuedFilters();
-        }
-
-        // use the ColumnDelete filter if hideColumns/showColumns is provided (must be done
-        // after queued filters are run so processed metrics can be removed, too)
-        $hideColumns = Common::getRequestVar('hideColumns', '', 'string', $this->request);
-        $showColumns = Common::getRequestVar('showColumns', '', 'string', $this->request);
-        if ($hideColumns !== '' || $showColumns !== '') {
-            $datatable->filter('ColumnDelete', array($hideColumns, $showColumns));
-        }
-
-        // apply label filter: only return rows matching the label parameter (more than one if more than one label)
-        if (!empty($label)) {
-            $addLabelIndex = Common::getRequestVar('labelFilterAddLabelIndex', 0, 'int', $this->request) == 1;
-
-            $filter = new LabelFilter($this->apiModule, $this->apiMethod, $this->request);
-            $datatable = $filter->filter($label, $datatable, $addLabelIndex);
-        }
+        $postProcessor = new DataTablePostProcessor($this->apiModule, $this->apiMethod, $this->request);
+        $datatable = $postProcessor->process($datatable);
 
         return $this->apiRenderer->renderDataTable($datatable);
     }
@@ -260,36 +200,6 @@ class ResponseBuilder
         return $this->apiRenderer->renderArray($array);
     }
 
-    /**
-     * Returns the value for the label query parameter which can be either a string
-     * (ie, label=...) or array (ie, label[]=...).
-     *
-     * @param array $request
-     * @return array
-     */
-    public static function getLabelFromRequest($request)
-    {
-        $label = Common::getRequestVar('label', array(), 'array', $request);
-        if (empty($label)) {
-            $label = Common::getRequestVar('label', '', 'string', $request);
-            if (!empty($label)) {
-                $label = array($label);
-            }
-        }
-
-        $label = self::unsanitizeLabelParameter($label);
-        return $label;
-    }
-
-    public static function unsanitizeLabelParameter($label)
-    {
-        // this is needed because Proxy uses Common::getRequestVar which in turn
-        // uses Common::sanitizeInputValue. This causes the > that separates recursive labels
-        // to become &gt; and we need to undo that here.
-        $label = Common::unsanitizeInputValues($label);
-        return $label;
-    }
-
     private function sendHeaderIfEnabled()
     {
         if ($this->sendHeader) {
diff --git a/core/Archive.php b/core/Archive.php
index 7101850c1d..b407465a45 100644
--- a/core/Archive.php
+++ b/core/Archive.php
@@ -744,7 +744,10 @@ class Archive
      */
     private function getArchiveGroupOfPlugin($plugin)
     {
-        if ($this->getPeriodLabel() != 'range') {
+        $periods = $this->params->getPeriods();
+        $periodLabel = reset($periods)->getLabel();
+        
+        if (Rules::shouldProcessReportsAllPlugins($this->params->getIdSites(), $this->params->getSegment(), $periodLabel)) {
             return self::ARCHIVE_ALL_PLUGINS_FLAG;
         }
 
diff --git a/core/Archive/DataTableFactory.php b/core/Archive/DataTableFactory.php
index 71eaa7a8c1..59af8a4e0b 100644
--- a/core/Archive/DataTableFactory.php
+++ b/core/Archive/DataTableFactory.php
@@ -10,6 +10,7 @@
 namespace Piwik\Archive;
 
 use Piwik\DataTable;
+use Piwik\DataTable\DataTableInterface;
 use Piwik\DataTable\Row;
 use Piwik\Site;
 
@@ -96,6 +97,23 @@ class DataTableFactory
     }
 
     /**
+     * Returns the ID of the site a table is related to based on the 'site' metadata entry,
+     * or null if there is none.
+     *
+     * @param DataTable $table
+     * @return int|null
+     */
+    public static function getSiteIdFromMetadata(DataTable $table)
+    {
+        $site = $table->getMetadata('site');
+        if (empty($site)) {
+            return null;
+        } else {
+            return $site->getId();
+        }
+    }
+
+    /**
      * Tells the factory instance to expand the DataTables that are created by
      * creating subtables and setting the subtable IDs of rows w/ subtables correctly.
      *
@@ -345,10 +363,10 @@ class DataTableFactory
      * Converts site IDs and period string ranges into Site instances and
      * Period instances in DataTable metadata.
      */
-    private function transformMetadata($table)
+    private function transformMetadata(DataTableInterface $table)
     {
         $periods = $this->periods;
-        $table->filter(function ($table) use ($periods) {
+        $table->filter(function (DataTable $table) use ($periods) {
             $table->setMetadata(DataTableFactory::TABLE_METADATA_SITE_INDEX, new Site($table->getMetadata(DataTableFactory::TABLE_METADATA_SITE_INDEX)));
             $table->setMetadata(DataTableFactory::TABLE_METADATA_PERIOD_INDEX, $periods[$table->getMetadata(DataTableFactory::TABLE_METADATA_PERIOD_INDEX)]);
         });
@@ -373,7 +391,7 @@ class DataTableFactory
      * @param $keyMetadata
      * @param $result
      */
-    private function setTableMetadata($keyMetadata, $result)
+    private function setTableMetadata($keyMetadata, DataTableInterface $result)
     {
         if (!isset($keyMetadata[DataTableFactory::TABLE_METADATA_SITE_INDEX])) {
             $keyMetadata[DataTableFactory::TABLE_METADATA_SITE_INDEX] = reset($this->sitesId);
@@ -385,7 +403,7 @@ class DataTableFactory
         }
 
         // Note: $result can be a DataTable\Map
-        $result->filter(function ($table) use ($keyMetadata) {
+        $result->filter(function (DataTable $table) use ($keyMetadata) {
             foreach ($keyMetadata as $name => $value) {
                 $table->setMetadata($name, $value);
             }
@@ -423,5 +441,4 @@ class DataTableFactory
         $result = $table;
         return $result;
     }
-}
-
+}
\ No newline at end of file
diff --git a/core/CronArchive.php b/core/CronArchive.php
index 151298fc6a..eb4e45e383 100644
--- a/core/CronArchive.php
+++ b/core/CronArchive.php
@@ -12,6 +12,7 @@ use Exception;
 use Piwik\ArchiveProcessor\Rules;
 use Piwik\CronArchive\FixedSiteIds;
 use Piwik\CronArchive\SharedSiteIds;
+use Piwik\Metrics\Formatter;
 use Piwik\Period\Factory as PeriodFactory;
 use Piwik\DataAccess\InvalidatedReports;
 use Piwik\Plugins\SitesManager\API as APISitesManager;
@@ -187,6 +188,8 @@ class CronArchive
     private $processed = 0;
     private $archivedPeriodsArchivesWebsite = 0;
 
+    private $formatter;
+
     /**
      * Returns the option name of the option that stores the time core:archive was last executed.
      *
@@ -209,6 +212,8 @@ class CronArchive
      */
     public function __construct($piwikUrl = false)
     {
+        $this->formatter = new Formatter();
+
         $this->initLog();
         $this->initPiwikHost($piwikUrl);
         $this->initCore();
@@ -489,7 +494,7 @@ class CronArchive
 
         if ($skipDayArchive) {
             $this->log("Skipped website id $idSite, already done "
-                . \Piwik\MetricsFormatter::getPrettyTimeFromSeconds($elapsedSinceLastArchiving, true, $isHtml = false)
+                . $this->formatter->getPrettyTimeFromSeconds($elapsedSinceLastArchiving, true)
                 . " ago, " . $timerWebsite->__toString());
             $this->skippedDayArchivesWebsites++;
             $this->skipped++;
@@ -503,7 +508,7 @@ class CronArchive
 
         if (!$shouldArchivePeriods) {
             $this->log("Skipped website id $idSite periods processing, already done "
-                . \Piwik\MetricsFormatter::getPrettyTimeFromSeconds($elapsedSinceLastArchiving, true, $isHtml = false)
+                . $this->formatter->getPrettyTimeFromSeconds($elapsedSinceLastArchiving, true)
                 . " ago, " . $timerWebsite->__toString());
             $this->skippedDayArchivesWebsites++;
             $this->skipped++;
@@ -860,6 +865,8 @@ class CronArchive
 
         $config->log = $log;
 
+        Log::unsetInstance();
+
         // Make sure we log at least INFO (if logger is set to DEBUG then keep it)
         $logLevel = Log::getInstance()->getLogLevel();
         if ($logLevel < Log::INFO) {
@@ -1048,7 +1055,7 @@ class CronArchive
     {
         $sitesIdWithVisits = APISitesManager::getInstance()->getSitesIdWithVisits(time() - $this->shouldArchiveOnlySitesWithTrafficSince);
         $websiteIds = !empty($sitesIdWithVisits) ? ", IDs: " . implode(", ", $sitesIdWithVisits) : "";
-        $prettySeconds = \Piwik\MetricsFormatter::getPrettyTimeFromSeconds( $this->shouldArchiveOnlySitesWithTrafficSince, true, false);
+        $prettySeconds = $this->formatter->getPrettyTimeFromSeconds( $this->shouldArchiveOnlySitesWithTrafficSince, true);
         $this->log("- Will process " . count($sitesIdWithVisits) . " websites with new visits since "
             . $prettySeconds
             . " "
@@ -1156,7 +1163,8 @@ class CronArchive
         // Try and not request older data we know is already archived
         if ($this->lastSuccessRunTimestamp !== false) {
             $dateLast = time() - $this->lastSuccessRunTimestamp;
-            $this->log("- Archiving was last executed without error " . \Piwik\MetricsFormatter::getPrettyTimeFromSeconds($dateLast, true, $isHtml = false) . " ago");
+            $this->log("- Archiving was last executed without error "
+                . $this->formatter->getPrettyTimeFromSeconds($dateLast, true) . " ago");
         }
     }
 
@@ -1213,6 +1221,10 @@ class CronArchive
 
         $today = end($stats);
 
+        if (empty($today['nb_visits'])) {
+            return 0;
+        }
+
         return $today['nb_visits'];
     }
 
diff --git a/core/DataTable.php b/core/DataTable.php
index 4d308f7d21..61e8abb1eb 100644
--- a/core/DataTable.php
+++ b/core/DataTable.php
@@ -200,6 +200,13 @@ class DataTable implements DataTableInterface, \IteratorAggregate, \ArrayAccess
     const LABEL_SUMMARY_ROW = -1;
 
     /**
+     * Name for metadata that contains extra {@link Piwik\Plugin\ProcessedMetric}s for a DataTable.
+     * These metrics will be added in addition to the ones specified in the table's associated
+     * {@link Piwik\Plugin\Report} class.
+     */
+    const EXTRA_PROCESSED_METRICS_METADATA_NAME = 'extra_processed_metrics';
+
+    /**
      * Maximum nesting level.
      */
     private static $maximumDepthLevelAllowed = self::MAX_DEPTH_DEFAULT;
@@ -1672,4 +1679,4 @@ class DataTable implements DataTableInterface, \IteratorAggregate, \ArrayAccess
     {
         $this->deleteRow($offset);
     }
-}
+}
\ No newline at end of file
diff --git a/core/DataTable/Filter/AddColumnsProcessedMetrics.php b/core/DataTable/Filter/AddColumnsProcessedMetrics.php
index f3d8191b1f..a3a9bd9776 100644
--- a/core/DataTable/Filter/AddColumnsProcessedMetrics.php
+++ b/core/DataTable/Filter/AddColumnsProcessedMetrics.php
@@ -11,7 +11,11 @@ namespace Piwik\DataTable\Filter;
 use Piwik\DataTable\BaseFilter;
 use Piwik\DataTable\Row;
 use Piwik\DataTable;
-use Piwik\Metrics;
+use Piwik\Plugin\Metric;
+use Piwik\Plugins\CoreHome\Columns\Metrics\ActionsPerVisit;
+use Piwik\Plugins\CoreHome\Columns\Metrics\AverageTimeOnSite;
+use Piwik\Plugins\CoreHome\Columns\Metrics\BounceRate;
+use Piwik\Plugins\CoreHome\Columns\Metrics\ConversionRate;
 
 /**
  * Adds processed metrics columns to a {@link DataTable} using metrics that already exist.
@@ -65,34 +69,21 @@ class AddColumnsProcessedMetrics extends BaseFilter
             $this->deleteRowsWithNoVisit($table);
         }
 
-        $metrics = new Metrics\Processed();
+        $extraProcessedMetrics = $table->getMetadata(DataTable::EXTRA_PROCESSED_METRICS_METADATA_NAME);
 
-        foreach ($table->getRows() as $row) {
-            $this->tryToAddColumn($row, 'conversion_rate', array($metrics, 'getConversionRate'));
-            $this->tryToAddColumn($row, 'nb_actions_per_visit', array($metrics, 'getActionsPerVisit'));
-            $this->tryToAddColumn($row, 'avg_time_on_site', array($metrics, 'getAvgTimeOnSite'));
-            $this->tryToAddColumn($row, 'bounce_rate', array($metrics, 'getBounceRate'));
+        $extraProcessedMetrics[] = new ConversionRate();
+        $extraProcessedMetrics[] = new ActionsPerVisit();
+        $extraProcessedMetrics[] = new AverageTimeOnSite();
+        $extraProcessedMetrics[] = new BounceRate();
 
-            $this->filterSubTable($row);
-        }
-    }
-
-    private function tryToAddColumn(Row $row, $column, $callable)
-    {
-        try {
-            $row->addColumn($column, $callable);
-        } catch (\Exception $e) {
-
-        }
+        $table->setMetadata(DataTable::EXTRA_PROCESSED_METRICS_METADATA_NAME, $extraProcessedMetrics);
     }
 
     private function deleteRowsWithNoVisit(DataTable $table)
     {
-        $metrics = new Metrics\Processed();
-
         foreach ($table->getRows() as $key => $row) {
-            $nbVisits  = $metrics->getColumn($row, Metrics::INDEX_NB_VISITS);
-            $nbActions = $metrics->getColumn($row, Metrics::INDEX_NB_ACTIONS);
+            $nbVisits  = Metric::getMetric($row, 'nb_visits');
+            $nbActions = Metric::getMetric($row, 'nb_actions');
 
             if ($nbVisits == 0
                 && $nbActions == 0
@@ -102,4 +93,4 @@ class AddColumnsProcessedMetrics extends BaseFilter
             }
         }
     }
-}
+}
\ No newline at end of file
diff --git a/core/DataTable/Filter/AddColumnsProcessedMetricsGoal.php b/core/DataTable/Filter/AddColumnsProcessedMetricsGoal.php
index 963ac9acbd..d63d9b9bc5 100644
--- a/core/DataTable/Filter/AddColumnsProcessedMetricsGoal.php
+++ b/core/DataTable/Filter/AddColumnsProcessedMetricsGoal.php
@@ -8,10 +8,18 @@
  */
 namespace Piwik\DataTable\Filter;
 
+use Piwik\Archive\DataTableFactory;
 use Piwik\DataTable;
 use Piwik\DataTable\Row;
-use Piwik\Metrics;
 use Piwik\Piwik;
+use Piwik\Plugin\Metric;
+use Piwik\Plugins\Goals\Columns\Metrics\GoalSpecific\AverageOrderRevenue;
+use Piwik\Plugins\Goals\Columns\Metrics\GoalSpecific\ConversionRate;
+use Piwik\Plugins\Goals\Columns\Metrics\GoalSpecific\Conversions;
+use Piwik\Plugins\Goals\Columns\Metrics\GoalSpecific\ItemsCount;
+use Piwik\Plugins\Goals\Columns\Metrics\GoalSpecific\Revenue;
+use Piwik\Plugins\Goals\Columns\Metrics\GoalSpecific\RevenuePerVisit as GoalSpecificRevenuePerVisit;
+use Piwik\Plugins\Goals\Columns\Metrics\RevenuePerVisit;
 
 /**
  * Adds goal related metrics to a {@link DataTable} using metrics that already exist.
@@ -66,8 +74,6 @@ class AddColumnsProcessedMetricsGoal extends AddColumnsProcessedMetrics
      */
     const GOALS_FULL_TABLE = 0;
 
-    private $expectedColumns = array();
-
     /**
      * Constructor.
      *
@@ -78,19 +84,14 @@ class AddColumnsProcessedMetricsGoal extends AddColumnsProcessedMetrics
      *                                  If self::GOALS_OVERVIEW, only the main goal metrics will be added.
      *                                  If an int > 0, then will process only metrics for this specific Goal.
      */
-    public function __construct($table, $enable = true, $processOnlyIdGoal)
+    public function __construct($table, $enable = true, $processOnlyIdGoal, $goalsToProcess = null)
     {
         $this->processOnlyIdGoal = $processOnlyIdGoal;
         $this->isEcommerce = $this->processOnlyIdGoal == Piwik::LABEL_ID_GOAL_IS_ECOMMERCE_ORDER || $this->processOnlyIdGoal == Piwik::LABEL_ID_GOAL_IS_ECOMMERCE_CART;
         parent::__construct($table);
         // Ensure that all rows with no visit but conversions will be displayed
         $this->deleteRowsWithNoVisit = false;
-    }
-
-    private function addColumn(Row $row, $columnName, $callback)
-    {
-        $this->expectedColumns[$columnName] = true;
-        $row->addColumn($columnName, $callback);
+        $this->goalsToProcess = $goalsToProcess;
     }
 
     /**
@@ -104,40 +105,27 @@ class AddColumnsProcessedMetricsGoal extends AddColumnsProcessedMetrics
         // Add standard processed metrics
         parent::filter($table);
 
-        $this->expectedColumns = array();
-
-        $metrics = new Metrics\ProcessedGoals();
-
-        foreach ($table->getRows() as $row) {
-            $goals = $metrics->getColumn($row, Metrics::INDEX_GOALS);
-
-            if (!$goals) {
-                continue;
-            }
-
-            $this->addColumn($row, 'revenue_per_visit', function (Row $row) use ($metrics) {
-                return $metrics->getRevenuePerVisit($row);
-            });
+        $goals = $this->getGoalsInTable($table);
+        if (!empty($this->goalsToProcess)) {
+            $goals = array_unique(array_merge($goals, $this->goalsToProcess));
+            sort($goals);
+        }
 
-            if ($this->processOnlyIdGoal == self::GOALS_MINIMAL_REPORT) {
-                continue;
-            }
+        $idSite = DataTableFactory::getSiteIdFromMetadata($table);
 
-            foreach ($goals as $goalId => $goalMetrics) {
-                $goalId = str_replace("idgoal=", "", $goalId);
+        $extraProcessedMetrics = $table->getMetadata(DataTable::EXTRA_PROCESSED_METRICS_METADATA_NAME);
 
+        $extraProcessedMetrics[] = new RevenuePerVisit();
+        if ($this->processOnlyIdGoal != self::GOALS_MINIMAL_REPORT) {
+            foreach ($goals as $idGoal) {
                 if (($this->processOnlyIdGoal > self::GOALS_FULL_TABLE
                         || $this->isEcommerce)
-                    && $this->processOnlyIdGoal != $goalId
+                    && $this->processOnlyIdGoal != $idGoal
                 ) {
                     continue;
                 }
 
-                $columnPrefix = 'goal_' . $goalId;
-
-                $this->addColumn($row, $columnPrefix . '_conversion_rate', function (Row $row) use ($metrics, $goalMetrics) {
-                    return $metrics->getConversionRate($row, $goalMetrics);
-                });
+                $extraProcessedMetrics[] = new ConversionRate($idSite, $idGoal); // PerGoal\ConversionRate
 
                 // When the table is displayed by clicking on the flag icon, we only display the columns
                 // Visits, Conversions, Per goal conversion rate, Revenue
@@ -145,51 +133,34 @@ class AddColumnsProcessedMetricsGoal extends AddColumnsProcessedMetrics
                     continue;
                 }
 
-                // Goal Conversions
-                $this->addColumn($row, $columnPrefix . '_nb_conversions', function () use ($metrics, $goalMetrics) {
-                    return $metrics->getNbConversions($goalMetrics);
-                });
-
-                // Goal Revenue per visit
-                $this->addColumn($row, $columnPrefix . '_revenue_per_visit', function (Row $row) use ($metrics, $goalMetrics) {
-                    return $metrics->getRevenuePerVisitForGoal($row, $goalMetrics);
-                });
-
-                // Total revenue
-                $this->addColumn($row, $columnPrefix . '_revenue', function () use ($metrics, $goalMetrics) {
-                    return $metrics->getRevenue($goalMetrics);
-                });
+                $extraProcessedMetrics[] = new Conversions($idSite, $idGoal); // PerGoal\Conversions or GoalSpecific\
+                $extraProcessedMetrics[] = new GoalSpecificRevenuePerVisit($idSite, $idGoal); // PerGoal\Revenue
+                $extraProcessedMetrics[] = new Revenue($idSite, $idGoal); // PerGoal\Revenue
 
                 if ($this->isEcommerce) {
-
-                    // AOV Average Order Value
-                    $this->addColumn($row, $columnPrefix . '_avg_order_revenue', function () use ($metrics, $goalMetrics) {
-                        return $metrics->getAvgOrderRevenue($goalMetrics);
-                    });
-
-                    // Items qty
-                    $this->addColumn($row, $columnPrefix . '_items', function () use ($metrics, $goalMetrics) {
-                        return $metrics->getItems($goalMetrics);
-                    });
-
+                    $extraProcessedMetrics[] = new AverageOrderRevenue($idSite, $idGoal);
+                    $extraProcessedMetrics[] = new ItemsCount($idSite, $idGoal);
                 }
             }
         }
 
-        $expectedColumns = array_keys($this->expectedColumns);
-        $rows = $table->getRows();
-        foreach ($rows as $row) {
-            foreach ($expectedColumns as $name) {
-                if (!$row->hasColumn($name)) {
-                    if (strpos($name, 'conversion_rate') !== false) {
-                        $row->addColumn($name, function () {
-                            return '0%';
-                        });
-                    } else {
-                        $row->addColumn($name, 0);
-                    }
-                }
+        $table->setMetadata(DataTable::EXTRA_PROCESSED_METRICS_METADATA_NAME, $extraProcessedMetrics);
+    }
+
+    private function getGoalsInTable(DataTable $table)
+    {
+        $result = array();
+        foreach ($table->getRows() as $row) {
+            $goals = Metric::getMetric($row, 'goals');
+            if (!$goals) {
+                continue;
+            }
+
+            foreach ($goals as $goalId => $goalMetrics) {
+                $goalId = str_replace("idgoal=", "", $goalId);
+                $result[] = $goalId;
             }
         }
+        return array_unique($result);
     }
-}
+}
\ No newline at end of file
diff --git a/core/DataTable/Filter/CalculateEvolutionFilter.php b/core/DataTable/Filter/CalculateEvolutionFilter.php
index 5fa55b329e..a8bd04d08d 100755
--- a/core/DataTable/Filter/CalculateEvolutionFilter.php
+++ b/core/DataTable/Filter/CalculateEvolutionFilter.php
@@ -27,6 +27,7 @@ use Piwik\Site;
  *     ((currentValue - pastValue) / pastValue) * 100
  *
  * @api
+ * @deprecated since v2.10.0
  */
 class CalculateEvolutionFilter extends ColumnCallbackAddColumnPercentage
 {
diff --git a/core/DataTable/Filter/ColumnCallbackReplace.php b/core/DataTable/Filter/ColumnCallbackReplace.php
index ca53405d7e..3e167b5593 100644
--- a/core/DataTable/Filter/ColumnCallbackReplace.php
+++ b/core/DataTable/Filter/ColumnCallbackReplace.php
@@ -29,6 +29,7 @@ use Piwik\DataTable\Row;
  *     // label, url and truncate_length are columns in $dataTable
  *     $dataTable->filter('ColumnCallbackReplace', array('label', 'url'), $truncateString, null, array('truncate_length'));
  *
+ * @api
  */
 class ColumnCallbackReplace extends BaseFilter
 {
diff --git a/core/DataTable/Filter/ExcludeLowPopulation.php b/core/DataTable/Filter/ExcludeLowPopulation.php
index ee135b59d6..cf54c5c7eb 100644
--- a/core/DataTable/Filter/ExcludeLowPopulation.php
+++ b/core/DataTable/Filter/ExcludeLowPopulation.php
@@ -10,6 +10,7 @@ namespace Piwik\DataTable\Filter;
 
 use Piwik\DataTable;
 use Piwik\DataTable\BaseFilter;
+use Piwik\Plugin\Metric;
 
 /**
  * Deletes all rows for which a specific column has a value that is lower than
@@ -59,6 +60,7 @@ class ExcludeLowPopulation extends BaseFilter
     public function __construct($table, $columnToFilter, $minimumValue, $minimumPercentageThreshold = false)
     {
         parent::__construct($table);
+
         $this->columnToFilter = $columnToFilter;
 
         if ($minimumValue == 0) {
diff --git a/core/DataTable/Filter/PivotByDimension.php b/core/DataTable/Filter/PivotByDimension.php
index ce3ac98ec5..61e68423e8 100644
--- a/core/DataTable/Filter/PivotByDimension.php
+++ b/core/DataTable/Filter/PivotByDimension.php
@@ -161,7 +161,7 @@ class PivotByDimension extends BaseFilter
         $this->pivotByColumnLimit = $pivotByColumnLimit ?: self::getDefaultColumnLimit();
         $this->isFetchingBySegmentEnabled = $isFetchingBySegmentEnabled;
 
-        $namesToId = Metrics::getMappingFromIdToName();
+        $namesToId = Metrics::getMappingFromNameToId();
         $this->metricIndexValue = isset($namesToId[$this->pivotColumn]) ? $namesToId[$this->pivotColumn] : null;
 
         $this->setPivotByDimension($pivotByDimension);
diff --git a/core/DataTable/Filter/Sort.php b/core/DataTable/Filter/Sort.php
index 9df2250288..6ffe33bced 100644
--- a/core/DataTable/Filter/Sort.php
+++ b/core/DataTable/Filter/Sort.php
@@ -192,7 +192,7 @@ class Sort extends BaseFilter
             return $this->columnToSort;
         }
 
-        $columnIdToName = Metrics::getMappingFromIdToName();
+        $columnIdToName = Metrics::getMappingFromNameToId();
         // sorting by "nb_visits" but the index is Metrics::INDEX_NB_VISITS in the table
         if (isset($columnIdToName[$this->columnToSort])) {
             $column = $columnIdToName[$this->columnToSort];
diff --git a/core/Error.php b/core/Error.php
index c56e3301a7..d8fa0706fc 100644
--- a/core/Error.php
+++ b/core/Error.php
@@ -148,7 +148,7 @@ class Error
             $htmlString = '';
             $htmlString .= "\n<div style='word-wrap: break-word; border: 3px solid red; padding:4px; width:70%; background-color:#FFFF96;'>
         <strong>There is an error. Please report the message (Piwik " . (class_exists('Piwik\Version') ? Version::VERSION : '') . ")
-        and full backtrace in the <a href='?module=Proxy&action=redirect&url=http://forum.piwik.org' target='_blank'>Piwik forums</a> (please do a Search first as it might have been reported already!).<br /><br/>
+        and full backtrace in the <a href='?module=Proxy&action=redirect&url=http://forum.piwik.org' rel='noreferrer' target='_blank'>Piwik forums</a> (please do a Search first as it might have been reported already!).<br /><br/>
         ";
             $htmlString .= Error::getErrNoString($message->errno);
             $htmlString .= ":</strong> <em>{$message->errstr}</em> in <strong>{$message->errfile}</strong>";
diff --git a/core/Metrics.php b/core/Metrics.php
index 0f8baf5a10..009fa36151 100644
--- a/core/Metrics.php
+++ b/core/Metrics.php
@@ -10,6 +10,7 @@ namespace Piwik;
 
 use Piwik\Cache\LanguageAwareStaticCache;
 use Piwik\Cache\PluginAwareStaticCache;
+use Piwik\Metrics\Formatter;
 
 require_once PIWIK_INCLUDE_PATH . "/core/Piwik.php";
 
@@ -183,11 +184,22 @@ class Metrics
         return $names;
     }
 
-    // TODO: this method is named wrong
-    public static function getMappingFromIdToName()
+    public static function getMappingFromNameToId()
     {
-        $idToName = array_flip(self::$mappingFromIdToName);
-        return $idToName;
+        static $nameToId = null;
+        if ($nameToId === null) {
+            $nameToId = array_flip(self::$mappingFromIdToName);
+        }
+        return $nameToId;
+    }
+
+    public static function getMappingFromNameToIdGoal()
+    {
+        static $nameToId = null;
+        if ($nameToId === null) {
+            $nameToId = array_flip(self::$mappingFromIdToNameGoal);
+        }
+        return $nameToId;
     }
 
     /**
@@ -223,7 +235,7 @@ class Metrics
     {
         $nameToUnit = array(
             '_rate'   => '%',
-            'revenue' => MetricsFormatter::getCurrencySymbol($idSite),
+            'revenue' => Formatter::getCurrencySymbol($idSite),
             '_time_'  => 's'
         );
 
diff --git a/core/Metrics/Base.php b/core/Metrics/Base.php
deleted file mode 100644
index 838d7c2ee6..0000000000
--- a/core/Metrics/Base.php
+++ /dev/null
@@ -1,61 +0,0 @@
-<?php
-/**
- * Piwik - free/libre analytics platform
- *
- * @link http://piwik.org
- * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
- *
- */
-namespace Piwik\Metrics;
-
-use Piwik\Metrics;
-use Piwik\DataTable\Row;
-
-class Base
-{
-    protected $invalidDivision = 0;
-    protected $roundPrecision = 2;
-
-    protected function getNumVisits(Row $row)
-    {
-        return (int) $this->getColumn($row, Metrics::INDEX_NB_VISITS);
-    }
-
-    /**
-     * Returns column from a given row.
-     * Will work with 2 types of datatable
-     * - raw datatables coming from the archive DB, which columns are int indexed
-     * - datatables processed resulting of API calls, which columns have human readable english names
-     *
-     * @param Row|array $row
-     * @param int $columnIdRaw see consts in Archive::
-     * @param bool|array $mappingIdToName
-     * @return mixed  Value of column, false if not found
-     */
-    public function getColumn($row, $columnIdRaw, $mappingIdToName = false)
-    {
-        if (empty($mappingIdToName)) {
-            $mappingIdToName = Metrics::$mappingFromIdToName;
-        }
-
-        $columnIdReadable = $mappingIdToName[$columnIdRaw];
-
-        if ($row instanceof Row) {
-            $raw = $row->getColumn($columnIdRaw);
-            if ($raw !== false) {
-                return $raw;
-            }
-            return $row->getColumn($columnIdReadable);
-        }
-
-        if (isset($row[$columnIdRaw])) {
-            return $row[$columnIdRaw];
-        }
-
-        if (isset($row[$columnIdReadable])) {
-            return $row[$columnIdReadable];
-        }
-
-        return false;
-    }
-}
\ No newline at end of file
diff --git a/core/Metrics/Formatter.php b/core/Metrics/Formatter.php
new file mode 100644
index 0000000000..0e5bbe719e
--- /dev/null
+++ b/core/Metrics/Formatter.php
@@ -0,0 +1,305 @@
+<?php
+/**
+ * Piwik - free/libre analytics platform
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ */
+namespace Piwik\Metrics;
+
+use Piwik\Common;
+use Piwik\DataTable;
+use Piwik\Piwik;
+use Piwik\Plugin\Metric;
+use Piwik\Plugin\ProcessedMetric;
+use Piwik\Plugin\Report;
+use Piwik\Site;
+use Piwik\Tracker\GoalManager;
+
+/**
+ * Contains methods to format metric values. Passed to the {@link \Piwik\Plugin\Metric::format()}
+ * method when formatting Metrics.
+ *
+ * @api
+ */
+class Formatter
+{
+    const PROCESSED_METRICS_FORMATTED_FLAG = 'processed_metrics_formatted';
+
+    private $decimalPoint = null;
+    private $thousandsSeparator = null;
+
+    /**
+     * Returns a prettified string representation of a number. The result will have
+     * thousands separators and a decimal point specific to the current locale, eg,
+     * `'1,000,000.05'` or `'1.000.000,05'`.
+     *
+     * @param number $value
+     * @return string
+     */
+    public function getPrettyNumber($value, $precision = 0)
+    {
+        if ($this->decimalPoint === null) {
+            $locale = localeconv();
+
+            $this->decimalPoint = $locale['decimal_point'];
+            $this->thousandsSeparator = $locale['thousands_sep'];
+        }
+
+        return number_format($value, $precision, $this->decimalPoint, $this->thousandsSeparator);
+    }
+
+    /**
+     * Returns a prettified time value (in seconds).
+     *
+     * @param int $numberOfSeconds The number of seconds.
+     * @param bool $displayTimeAsSentence If set to true, will output `"5min 17s"`, if false `"00:05:17"`.
+     * @param bool $round Whether to round to the nearest second or not.
+     * @return string
+     */
+    public function getPrettyTimeFromSeconds($numberOfSeconds, $displayTimeAsSentence = false, $round = false)
+    {
+        $numberOfSeconds = $round ? (int)$numberOfSeconds : (float)$numberOfSeconds;
+
+        $isNegative = false;
+        if ($numberOfSeconds < 0) {
+            $numberOfSeconds = -1 * $numberOfSeconds;
+            $isNegative = true;
+        }
+
+        // Display 01:45:17 time format
+        if ($displayTimeAsSentence === false) {
+            $hours   = floor($numberOfSeconds / 3600);
+            $minutes = floor(($reminder = ($numberOfSeconds - $hours * 3600)) / 60);
+            $seconds = floor($reminder - $minutes * 60);
+            $time    = sprintf("%02s", $hours) . ':' . sprintf("%02s", $minutes) . ':' . sprintf("%02s", $seconds);
+            $centiSeconds = ($numberOfSeconds * 100) % 100;
+            if ($centiSeconds) {
+                $time .= '.' . sprintf("%02s", $centiSeconds);
+            }
+            if ($isNegative) {
+                $time = '-' . $time;
+            }
+            return $time;
+        }
+        $secondsInYear = 86400 * 365.25;
+
+        $years      = floor($numberOfSeconds / $secondsInYear);
+        $minusYears = $numberOfSeconds - $years * $secondsInYear;
+        $days       = floor($minusYears / 86400);
+
+        $minusDays = $numberOfSeconds - $days * 86400;
+        $hours     = floor($minusDays / 3600);
+
+        $minusDaysAndHours = $minusDays - $hours * 3600;
+        $minutes = floor($minusDaysAndHours / 60);
+
+        $seconds   = $minusDaysAndHours - $minutes * 60;
+        $precision = ($seconds > 0 && $seconds < 0.01 ? 3 : 2);
+        $seconds   = round($seconds, $precision);
+
+        if ($years > 0) {
+            $return = sprintf(Piwik::translate('General_YearsDays'), $years, $days);
+        } elseif ($days > 0) {
+            $return = sprintf(Piwik::translate('General_DaysHours'), $days, $hours);
+        } elseif ($hours > 0) {
+            $return = sprintf(Piwik::translate('General_HoursMinutes'), $hours, $minutes);
+        } elseif ($minutes > 0) {
+            $return = sprintf(Piwik::translate('General_MinutesSeconds'), $minutes, $seconds);
+        } else {
+            $return = sprintf(Piwik::translate('General_Seconds'), $seconds);
+        }
+
+        if ($isNegative) {
+            $return = '-' . $return;
+        }
+
+        return $return;
+    }
+
+    /**
+     * Returns a prettified memory size value.
+     *
+     * @param number $size The size in bytes.
+     * @param string $unit The specific unit to use, if any. If null, the unit is determined by $size.
+     * @param int $precision The precision to use when rounding.
+     * @return string eg, `'128 M'` or `'256 K'`.
+     */
+    public function getPrettySizeFromBytes($size, $unit = null, $precision = 1)
+    {
+        if ($size == 0) {
+            return '0 M';
+        }
+
+        $units = array('B', 'K', 'M', 'G', 'T');
+
+        $currentUnit = null;
+        foreach ($units as $idx => $currentUnit) {
+            if ($size >= 1024 && $unit != $currentUnit && $idx != count($units) - 1) {
+                $size = $size / 1024;
+            } else {
+                break;
+            }
+        }
+
+        return round($size, $precision) . " " . $currentUnit;
+    }
+
+    /**
+     * Returns a pretty formated monetary value using the currency associated with a site.
+     *
+     * @param int|string $value The monetary value to format.
+     * @param int $idSite The ID of the site whose currency will be used.
+     * @return string
+     */
+    public function getPrettyMoney($value, $idSite)
+    {
+        $space = ' ';
+
+        $currencySymbol = self::getCurrencySymbol($idSite);
+
+        $currencyBefore =  $currencySymbol . $space;
+        $currencyAfter = '';
+
+        // (maybe more currencies prefer this notation?)
+        $currencySymbolToAppend = array('€', 'kr', 'zł');
+
+        // manually put the currency symbol after the amount
+        if (in_array($currencySymbol, $currencySymbolToAppend)) {
+            $currencyAfter = $space . $currencySymbol;
+            $currencyBefore = '';
+        }
+
+        // if the input is a number (it could be a string or INPUT form),
+        // and if this number is not an int, we round to precision 2
+        if (is_numeric($value)) {
+            if ($value == round($value)) {
+                // 0.0 => 0
+                $value = round($value);
+            } else {
+                $precision = GoalManager::REVENUE_PRECISION;
+                $value = sprintf("%01." . $precision . "f", $value);
+            }
+        }
+
+        $prettyMoney = $currencyBefore . $value . $currencyAfter;
+        return $prettyMoney;
+    }
+
+    /**
+     * Returns a percent string from a quotient value. Forces the use of a '.'
+     * decimal place.
+     *
+     * @param float $value
+     * @return string
+     */
+    public function getPrettyPercentFromQuotient($value)
+    {
+        $result = ($value * 100) . '%';
+        return Common::forceDotAsSeparatorForDecimalPoint($result);
+    }
+
+    /**
+     * Returns the currency symbol for a site.
+     *
+     * @param int $idSite The ID of the site to return the currency symbol for.
+     * @return string eg, `'$'`.
+     */
+    public static function getCurrencySymbol($idSite)
+    {
+        $symbols  = self::getCurrencyList();
+        $currency = Site::getCurrencyFor($idSite);
+
+        if (isset($symbols[$currency])) {
+            return $symbols[$currency][0];
+        }
+
+        return '';
+    }
+
+    /**
+     * Returns the list of all known currency symbols.
+     *
+     * @return array An array mapping currency codes to their respective currency symbols
+     *               and a description, eg, `array('USD' => array('$', 'US dollar'))`.
+     */
+    public static function getCurrencyList()
+    {
+        static $currenciesList = null;
+
+        if (is_null($currenciesList)) {
+            require_once PIWIK_INCLUDE_PATH . '/core/DataFiles/Currencies.php';
+            $currenciesList = $GLOBALS['Piwik_CurrencyList'];
+        }
+
+        return $currenciesList;
+    }
+
+    /**
+     * Formats all metrics, including processed metrics, for a DataTable. Metrics to format
+     * are found through report metadata and DataTable metadata.
+     *
+     * @param DataTable $dataTable The table to format metrics for.
+     * @param Report|null $report The report the table belongs to.
+     * @param string[]|null $metricsToFormat Whitelist of names of metrics to format.
+     */
+    public function formatMetrics(DataTable $dataTable, Report $report = null, $metricsToFormat = null)
+    {
+        $metrics = $this->getMetricsToFormat($dataTable, $report);
+        if (empty($metrics)
+            || $dataTable->getMetadata(self::PROCESSED_METRICS_FORMATTED_FLAG)
+        ) {
+            return;
+        }
+
+        $dataTable->setMetadata(self::PROCESSED_METRICS_FORMATTED_FLAG, true);
+
+        if ($metricsToFormat !== null) {
+            $metricMatchRegex = $this->makeRegexToMatchMetrics($metricsToFormat);
+            $metrics = array_filter($metrics, function (ProcessedMetric $metric) use ($metricMatchRegex) {
+                return preg_match($metricMatchRegex, $metric->getName());
+            });
+        }
+
+        foreach ($metrics as $name => $metric) {
+            if (!$metric->beforeFormat($report, $dataTable)) {
+                continue;
+            }
+
+            foreach ($dataTable->getRows() as $row) {
+                $columnValue = $row->getColumn($name);
+                if ($columnValue !== false) {
+                    $row->setColumn($name, $metric->format($columnValue, $this));
+                }
+
+                $subtable = $row->getSubtable();
+                if (!empty($subtable)) {
+                    $this->formatMetrics($subtable, $report, $metricsToFormat);
+                }
+            }
+        }
+    }
+
+    private function makeRegexToMatchMetrics($metricsToFormat)
+    {
+        $metricsRegexParts = array();
+        foreach ($metricsToFormat as $metricFilter) {
+            if ($metricFilter[0] == '/') {
+                $metricsRegexParts[] = '(?:' . substr($metricFilter, 1, strlen($metricFilter) - 2) . ')';
+            } else {
+                $metricsRegexParts[] = preg_quote($metricFilter);
+            }
+        }
+        return '/^' . implode('|', $metricsRegexParts) . '$/';
+    }
+
+    /**
+     * @param DataTable $dataTable
+     * @param Report $report
+     * @return Metric[]
+     */
+    private function getMetricsToFormat(DataTable $dataTable, Report $report = null)
+    {
+        return Report::getMetricsForTable($dataTable, $report, $baseType = 'Piwik\\Plugin\\Metric');
+    }
+}
\ No newline at end of file
diff --git a/core/Metrics/Formatter/Html.php b/core/Metrics/Formatter/Html.php
new file mode 100644
index 0000000000..c4f9e05664
--- /dev/null
+++ b/core/Metrics/Formatter/Html.php
@@ -0,0 +1,43 @@
+<?php
+/**
+ * Piwik - free/libre analytics platform
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ */
+namespace Piwik\Metrics\Formatter;
+
+use Piwik\Metrics\Formatter;
+
+/**
+ * Metrics formatter that formats for HTML output. Uses non-breaking spaces in formatted values
+ * so text will stay unbroken in HTML views.
+ */
+class Html extends Formatter
+{
+    public function getPrettyTimeFromSeconds($numberOfSeconds, $displayTimeAsSentence = true, $round = false)
+    {
+        $result = parent::getPrettyTimeFromSeconds($numberOfSeconds, $displayTimeAsSentence, $round);
+        $result = $this->replaceSpaceWithNonBreakingSpace($result);
+        return $result;
+    }
+
+    public function getPrettySizeFromBytes($size, $unit = null, $precision = 1)
+    {
+        $result = parent::getPrettySizeFromBytes($size, $unit, $precision);
+        $result = $this->replaceSpaceWithNonBreakingSpace($result);
+        return $result;
+    }
+
+    public function getPrettyMoney($value, $idSite)
+    {
+        $result = parent::getPrettyMoney($value, $idSite);
+        $result = $this->replaceSpaceWithNonBreakingSpace($result);
+        return $result;
+    }
+
+    private function replaceSpaceWithNonBreakingSpace($value)
+    {
+        return str_replace(' ', '&nbsp;', $value);
+    }
+}
\ No newline at end of file
diff --git a/core/Metrics/Processed.php b/core/Metrics/Processed.php
deleted file mode 100644
index 0e6b7c969b..0000000000
--- a/core/Metrics/Processed.php
+++ /dev/null
@@ -1,68 +0,0 @@
-<?php
-/**
- * Piwik - free/libre analytics platform
- *
- * @link http://piwik.org
- * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
- *
- */
-namespace Piwik\Metrics;
-
-use Piwik\Metrics;
-use Piwik\DataTable\Row;
-use Piwik\DataTable;
-
-class Processed extends Base
-{
-
-    public function getConversionRate(Row $row)
-    {
-        $nbVisits = $this->getNumVisits($row);
-
-        $nbVisitsConverted = (int) $this->getColumn($row, Metrics::INDEX_NB_VISITS_CONVERTED);
-        if ($nbVisitsConverted > 0) {
-            $conversionRate = round(100 * $nbVisitsConverted / $nbVisits, $this->roundPrecision);
-
-            return $conversionRate . '%';
-        }
-    }
-
-    public function getActionsPerVisit(Row $row)
-    {
-        $nbVisits  = $this->getNumVisits($row);
-        $nbActions = $this->getColumn($row, Metrics::INDEX_NB_ACTIONS);
-
-        if ($nbVisits == 0) {
-            return $this->invalidDivision;
-        }
-
-        return round($nbActions / $nbVisits, $this->roundPrecision);
-    }
-
-    public function getAvgTimeOnSite(Row $row)
-    {
-        $nbVisits = $this->getNumVisits($row);
-
-        if ($nbVisits == 0) {
-            return $this->invalidDivision;
-        }
-
-        $visitLength = $this->getColumn($row, Metrics::INDEX_SUM_VISIT_LENGTH);
-
-        return round($visitLength / $nbVisits, $rounding = 0);
-    }
-
-    public function getBounceRate(Row $row)
-    {
-        $nbVisits = $this->getNumVisits($row);
-
-        if ($nbVisits == 0) {
-            return $this->invalidDivision;
-        }
-
-        $bounceRate = round(100 * $this->getColumn($row, Metrics::INDEX_BOUNCE_COUNT) / $nbVisits, $this->roundPrecision);
-
-        return $bounceRate . "%";
-    }
-
-}
\ No newline at end of file
diff --git a/core/Metrics/ProcessedGoals.php b/core/Metrics/ProcessedGoals.php
deleted file mode 100644
index 6fb62231f3..0000000000
--- a/core/Metrics/ProcessedGoals.php
+++ /dev/null
@@ -1,123 +0,0 @@
-<?php
-/**
- * Piwik - free/libre analytics platform
- *
- * @link http://piwik.org
- * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
- *
- */
-namespace Piwik\Metrics;
-
-use Piwik\Metrics;
-use Piwik\DataTable\Row;
-use Piwik\DataTable;
-use Piwik\Piwik;
-use Piwik\Tracker\GoalManager;
-
-class ProcessedGoals extends Base
-{
-
-    public function getRevenuePerVisit(Row $row)
-    {
-        $goals = $this->getColumn($row, Metrics::INDEX_GOALS);
-
-        $revenue = 0;
-        foreach ($goals as $goalId => $goalMetrics) {
-            if ($goalId == Piwik::LABEL_ID_GOAL_IS_ECOMMERCE_CART) {
-                continue;
-            }
-            if ($goalId >= GoalManager::IDGOAL_ORDER
-                || $goalId == Piwik::LABEL_ID_GOAL_IS_ECOMMERCE_ORDER
-            ) {
-                $revenue += (int) $this->getColumn($goalMetrics, Metrics::INDEX_GOAL_REVENUE, Metrics::$mappingFromIdToNameGoal);
-            }
-        }
-
-        if ($revenue == 0) {
-            $revenue = (int) $this->getColumn($row, Metrics::INDEX_REVENUE);
-        }
-
-        $nbVisits    = $this->getNumVisits($row);
-        $conversions = (int) $this->getColumn($row, Metrics::INDEX_NB_CONVERSIONS);
-
-        // If no visit for this metric, but some conversions, we still want to display some kind of "revenue per visit"
-        // even though it will actually be in this edge case "Revenue per conversion"
-        $revenuePerVisit = $this->invalidDivision;
-
-        if ($nbVisits > 0
-            || $conversions > 0
-        ) {
-            $revenuePerVisit = round($revenue / ($nbVisits == 0 ? $conversions : $nbVisits), GoalManager::REVENUE_PRECISION);
-        }
-
-        return $revenuePerVisit;
-    }
-
-    public function getConversionRate(Row $row, $goalMetrics)
-    {
-        $nbVisits = $this->getNumVisits($row);
-
-        if ($nbVisits == 0) {
-            $value = $this->invalidDivision;
-        } else {
-            $conversions = $this->getNbConversions($goalMetrics);
-            $value = round(100 * $conversions / $nbVisits, GoalManager::REVENUE_PRECISION);
-        }
-
-        if (empty($value)) {
-            return '0%';
-        }
-
-        return $value . "%";
-    }
-
-    public function getNbConversions($goalMetrics)
-    {
-        return (int) $this->getColumn($goalMetrics,
-                                      Metrics::INDEX_GOAL_NB_CONVERSIONS,
-                                      Metrics::$mappingFromIdToNameGoal);
-    }
-
-    public function getRevenue($goalMetrics)
-    {
-        return (float) $this->getColumn($goalMetrics,
-                                        Metrics::INDEX_GOAL_REVENUE,
-                                        Metrics::$mappingFromIdToNameGoal);
-    }
-
-    public function getRevenuePerVisitForGoal(Row $row, $goalMetrics)
-    {
-        $nbVisits = $this->getNumVisits($row);
-
-        $div = $nbVisits;
-        if ($nbVisits == 0) {
-            $div = $this->getNbConversions($goalMetrics);
-        }
-
-        $goalRevenue = $this->getRevenue($goalMetrics);
-
-        return round($goalRevenue / $div, GoalManager::REVENUE_PRECISION);
-    }
-
-    public function getAvgOrderRevenue($goalMetrics)
-    {
-        $goalRevenue = $this->getRevenue($goalMetrics);
-        $conversions = $this->getNbConversions($goalMetrics);
-
-        return $goalRevenue / $conversions;
-    }
-
-    public function getItems($goalMetrics)
-    {
-        $items = $this->getColumn($goalMetrics,
-                                  Metrics::INDEX_GOAL_ECOMMERCE_ITEMS,
-                                  Metrics::$mappingFromIdToNameGoal);
-
-        if (empty($items)) {
-            return 0;
-        }
-
-        return $items;
-    }
-
-}
\ No newline at end of file
diff --git a/core/MetricsFormatter.php b/core/MetricsFormatter.php
index 8554663525..daa8710fc6 100644
--- a/core/MetricsFormatter.php
+++ b/core/MetricsFormatter.php
@@ -4,251 +4,69 @@
  *
  * @link http://piwik.org
  * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
- *
  */
 namespace Piwik;
 
-use Piwik\Tracker\GoalManager;
+use Piwik\Metrics\Formatter;
+use Piwik\Plugins\API\ProcessedReport;
 
 /**
  * Contains helper function that format numerical values in different ways.
  *
- * @api
+ * @deprecated
  */
 class MetricsFormatter
 {
-    /**
-     * Returns a prettified string representation of a number. The result will have
-     * thousands separators and a decimal point specific to the current locale, eg,
-     * `'1,000,000.05'` or `'1.000.000,05'`.
-     *
-     * @param number $value
-     * @return string
-     */
-    public static function getPrettyNumber($value)
-    {
-        static $decimalPoint = null;
-        static $thousandsSeparator = null;
-
-        if ($decimalPoint === null) {
-            $locale = localeconv();
-
-            $decimalPoint = $locale['decimal_point'];
-            $thousandsSeparator = $locale['thousands_sep'];
-        }
-
-        return number_format($value, 0, $decimalPoint, $thousandsSeparator);
-    }
+    private static $formatter = null;
+    private static $htmlFormatter = null;
 
-    /**
-     * Returns a prettified time value (in seconds).
-     *
-     * @param int $numberOfSeconds The number of seconds.
-     * @param bool $displayTimeAsSentence If set to true, will output `"5min 17s"`, if false `"00:05:17"`.
-     * @param bool $isHtml If true, replaces all spaces with `'&nbsp;'`.
-     * @param bool $round Whether to round to the nearest second or not.
-     * @return string
-     */
-    public static function getPrettyTimeFromSeconds($numberOfSeconds, $displayTimeAsSentence = true, $isHtml = true, $round = false)
+    public static function getFormatter($isHtml = false)
     {
-        $numberOfSeconds = $round ? (int)$numberOfSeconds : (float)$numberOfSeconds;
-
-        $isNegative = false;
-        if ($numberOfSeconds < 0) {
-            $numberOfSeconds = -1 * $numberOfSeconds;
-            $isNegative = true;
-        }
-
-        // Display 01:45:17 time format
-        if ($displayTimeAsSentence === false) {
-            $hours   = floor($numberOfSeconds / 3600);
-            $minutes = floor(($reminder = ($numberOfSeconds - $hours * 3600)) / 60);
-            $seconds = floor($reminder - $minutes * 60);
-            $time    = sprintf("%02s", $hours) . ':' . sprintf("%02s", $minutes) . ':' . sprintf("%02s", $seconds);
-            $centiSeconds = ($numberOfSeconds * 100) % 100;
-            if ($centiSeconds) {
-                $time .= '.' . sprintf("%02s", $centiSeconds);
-            }
-            if ($isNegative) {
-                $time = '-' . $time;
+        if ($isHtml) {
+            if (self::$formatter === null) {
+                self::$formatter = new Formatter();
             }
-            return $time;
-        }
-        $secondsInYear = 86400 * 365.25;
-
-        $years      = floor($numberOfSeconds / $secondsInYear);
-        $minusYears = $numberOfSeconds - $years * $secondsInYear;
-        $days       = floor($minusYears / 86400);
-
-        $minusDays = $numberOfSeconds - $days * 86400;
-        $hours     = floor($minusDays / 3600);
-
-        $minusDaysAndHours = $minusDays - $hours * 3600;
-        $minutes = floor($minusDaysAndHours / 60);
-
-        $seconds   = $minusDaysAndHours - $minutes * 60;
-        $precision = ($seconds > 0 && $seconds < 0.01 ? 3 : 2);
-        $seconds   = round($seconds, $precision);
-
-        if ($years > 0) {
-            $return = sprintf(Piwik::translate('General_YearsDays'), $years, $days);
-        } elseif ($days > 0) {
-            $return = sprintf(Piwik::translate('General_DaysHours'), $days, $hours);
-        } elseif ($hours > 0) {
-            $return = sprintf(Piwik::translate('General_HoursMinutes'), $hours, $minutes);
-        } elseif ($minutes > 0) {
-            $return = sprintf(Piwik::translate('General_MinutesSeconds'), $minutes, $seconds);
+            return self::$formatter;
         } else {
-            $return = sprintf(Piwik::translate('General_Seconds'), $seconds);
-        }
-
-        if ($isNegative) {
-            $return = '-' . $return;
+            if (self::$htmlFormatter === null) {
+                self::$htmlFormatter = new Formatter\Html();
+            }
+            return self::$htmlFormatter;
         }
+    }
 
-        if ($isHtml) {
-            return str_replace(' ', '&nbsp;', $return);
-        }
+    public static function getPrettyNumber($value)
+    {
+        return self::getFormatter()->getPrettyNumber($value);
+    }
 
-        return $return;
+    public static function getPrettyTimeFromSeconds($numberOfSeconds, $displayTimeAsSentence = true, $isHtml = true, $round = false)
+    {
+        return self::getFormatter($isHtml)->getPrettyTimeFromSeconds($numberOfSeconds, $displayTimeAsSentence, $round);
     }
 
-    /**
-     * Returns a prettified memory size value.
-     *
-     * @param number $size The size in bytes.
-     * @param string $unit The specific unit to use, if any. If null, the unit is determined by $size.
-     * @param int $precision The precision to use when rounding.
-     * @return string eg, `'128 M'` or `'256 K'`.
-     */
     public static function getPrettySizeFromBytes($size, $unit = null, $precision = 1)
     {
-        if ($size == 0) {
-            return '0 M';
-        }
-
-        $units = array('B', 'K', 'M', 'G', 'T');
-        foreach ($units as $currentUnit) {
-            if ($size >= 1024 && $unit != $currentUnit) {
-                $size = $size / 1024;
-            } else {
-                break;
-            }
-        }
-
-        return round($size, $precision) . " " . $currentUnit;
+        return self::getFormatter()->getPrettySizeFromBytes($size, $unit, $precision);
     }
 
-    /**
-     * Returns a pretty formated monetary value using the currency associated with a site.
-     *
-     * @param int|string $value The monetary value to format.
-     * @param int $idSite The ID of the site whose currency will be used.
-     * @param bool $isHtml If true, replaces all spaces with `'&nbsp;'`.
-     * @return string
-     */
     public static function getPrettyMoney($value, $idSite, $isHtml = true)
     {
-        $currencyBefore = MetricsFormatter::getCurrencySymbol($idSite);
-
-        $space = ' ';
-        if ($isHtml) {
-            $space = '&nbsp;';
-        }
-
-        $currencyAfter = '';
-        // (maybe more currencies prefer this notation?)
-        $currencySymbolToAppend = array('€', 'kr', 'zł');
-
-        // manually put the currency symbol after the amount
-        if (in_array($currencyBefore, $currencySymbolToAppend)) {
-            $currencyAfter = $space . $currencyBefore;
-            $currencyBefore = '';
-        }
-
-        // if the input is a number (it could be a string or INPUT form),
-        // and if this number is not an int, we round to precision 2
-        if (is_numeric($value)) {
-            if ($value == round($value)) {
-                // 0.0 => 0
-                $value = round($value);
-            } else {
-                $precision = GoalManager::REVENUE_PRECISION;
-                $value = sprintf("%01." . $precision . "f", $value);
-            }
-        }
-
-        $prettyMoney = $currencyBefore . $space . $value . $currencyAfter;
-        return $prettyMoney;
+        return self::getFormatter($isHtml)->getPrettyMoney($value, $idSite);
     }
 
-    /**
-     * Prettifies a metric value based on the column name.
-     *
-     * @param int $idSite The ID of the site the metric is for (used if the column value is an amount of money).
-     * @param string $columnName The metric name.
-     * @param mixed $value The metric value.
-     * @param bool $isHtml If true, replaces all spaces with `'&nbsp;'`.
-     * @return string
-     */
     public static function getPrettyValue($idSite, $columnName, $value, $isHtml)
     {
-        // Display time in human readable
-        if (strpos($columnName, 'time') !== false) {
-            // Little hack: Display 15s rather than 00:00:15, only for "(avg|min|max)_generation_time"
-            $timeAsSentence = (substr($columnName, -16) == '_time_generation');
-            return self::getPrettyTimeFromSeconds($value, $timeAsSentence);
-        }
-
-        // Add revenue symbol to revenues
-        if (strpos($columnName, 'revenue') !== false && strpos($columnName, 'evolution') === false) {
-            return self::getPrettyMoney($value, $idSite, $isHtml);
-        }
-
-        // Add % symbol to rates
-        if (strpos($columnName, '_rate') !== false) {
-            if (strpos($value, "%") === false) {
-                return $value . "%";
-            }
-        }
-
-        return $value;
+        return ProcessedReport::getPrettyValue(self::getFormatter($isHtml), $idSite, $columnName, $value);
     }
 
-    /**
-     * Returns the currency symbol for a site.
-     *
-     * @param int $idSite The ID of the site to return the currency symbol for.
-     * @return string eg, `'$'`.
-     */
     public static function getCurrencySymbol($idSite)
     {
-        $symbols  = MetricsFormatter::getCurrencyList();
-        $site     = new Site($idSite);
-        $currency = $site->getCurrency();
-
-        if (isset($symbols[$currency])) {
-            return $symbols[$currency][0];
-        }
-
-        return '';
+        return Formatter::getCurrencySymbol($idSite);
     }
 
-    /**
-     * Returns the list of all known currency symbols.
-     *
-     * @return array An array mapping currency codes to their respective currency symbols
-     *               and a description, eg, `array('USD' => array('$', 'US dollar'))`.
-     */
     public static function getCurrencyList()
     {
-        static $currenciesList = null;
-
-        if (is_null($currenciesList)) {
-            require_once PIWIK_INCLUDE_PATH . '/core/DataFiles/Currencies.php';
-            $currenciesList = $GLOBALS['Piwik_CurrencyList'];
-        }
-
-        return $currenciesList;
+        return Formatter::getCurrencyList();
     }
 }
diff --git a/core/Piwik.php b/core/Piwik.php
index 80ed01cd8c..bc5244dd52 100644
--- a/core/Piwik.php
+++ b/core/Piwik.php
@@ -112,10 +112,23 @@ class Piwik
      */
     public static function getPercentageSafe($dividend, $divisor, $precision = 0)
     {
+        return self::getQuotientSafe(100 * $dividend, $divisor, $precision);
+    }
+
+    /**
+     * Safely compute a ratio. Returns 0 if divisor is 0 (to avoid division by 0 error).
+     *
+     * @param number $dividend
+     * @param number $divisor
+     * @param int $precision
+     * @return number
+     */
+    public static function getQuotientSafe($dividend, $divisor, $precision = 0)
+    {
         if ($divisor == 0) {
             return 0;
         }
-        return round(100 * $dividend / $divisor, $precision);
+        return round($dividend / $divisor, $precision);
     }
 
     /**
diff --git a/core/Plugin/AggregatedMetric.php b/core/Plugin/AggregatedMetric.php
new file mode 100644
index 0000000000..7df1535727
--- /dev/null
+++ b/core/Plugin/AggregatedMetric.php
@@ -0,0 +1,22 @@
+<?php
+/**
+ * Piwik - free/libre analytics platform
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ */
+namespace Piwik\Plugin;
+
+use Piwik\DataTable\Row;
+
+/**
+ * Base type for metric metadata classes that describe aggregated metrics. These metrics are
+ * computed in the backend data store and are aggregated in PHP when Piwik archives period reports.
+ *
+ * Note: This class is a placeholder. It will be filled out at a later date. Right now, only
+ * processed metrics can be defined this way.
+ */
+abstract class AggregatedMetric extends Metric
+{
+    // stub, to be filled out later
+}
\ No newline at end of file
diff --git a/core/Plugin/ComponentFactory.php b/core/Plugin/ComponentFactory.php
index 9cb9cd1c1b..68415e9397 100644
--- a/core/Plugin/ComponentFactory.php
+++ b/core/Plugin/ComponentFactory.php
@@ -74,7 +74,7 @@ class ComponentFactory
      * @param callback $predicate
      * @return mixed The component that satisfies $predicate or null if not found.
      */
-    public static function getComponentif ($componentTypeClass, $pluginName, $predicate)
+    public static function getComponentIf($componentTypeClass, $pluginName, $predicate)
     {
         $pluginManager = PluginManager::getInstance();
 
diff --git a/core/Plugin/ControllerAdmin.php b/core/Plugin/ControllerAdmin.php
index 746395e88e..008cb4d2f4 100644
--- a/core/Plugin/ControllerAdmin.php
+++ b/core/Plugin/ControllerAdmin.php
@@ -131,7 +131,7 @@ abstract class ControllerAdmin extends Controller
         $message = sprintf("You are using the PHP accelerator & optimizer eAccelerator which is known to be not compatible with Piwik.
             We have disabled eAccelerator, which might affect the performance of Piwik.
             Read the %srelated ticket%s for more information and how to fix this problem.",
-            '<a target="_blank" href="https://github.com/piwik/piwik/issues/4439">', '</a>');
+            '<a rel="noreferrer" target="_blank" href="https://github.com/piwik/piwik/issues/4439">', '</a>');
 
         $notification = new Notification($message);
         $notification->context = Notification::CONTEXT_WARNING;
diff --git a/core/Plugin/Metric.php b/core/Plugin/Metric.php
new file mode 100644
index 0000000000..e475eb837f
--- /dev/null
+++ b/core/Plugin/Metric.php
@@ -0,0 +1,179 @@
+<?php
+/**
+ * Piwik - free/libre analytics platform
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ */
+namespace Piwik\Plugin;
+
+use Piwik\DataTable;
+use Piwik\DataTable\Row;
+use Piwik\Metrics;
+use Piwik\Metrics\Formatter;
+
+/**
+ * Base type of metric metadata classes.
+ *
+ * A metric metadata class is a class that describes how a metric is described, computed and
+ * formatted.
+ *
+ * There are two types of metrics: aggregated and processed. An aggregated metric is computed
+ * in the backend datastore and aggregated in PHP when archiving period reports.
+ *
+ * Currently, only processed metrics can be defined as metric metadata classes. Support for
+ * aggregated metrics will be added at a later date.
+ *
+ * See {@link Piwik\Plugin\ProcessedMetric} and {@link Piwik\Plugin|AggregatedMetric}.
+ *
+ * @api
+ */
+abstract class Metric
+{
+    /**
+     * The sub-namespace name in a plugin where Metric components are stored.
+     */
+    const COMPONENT_SUBNAMESPACE = 'Metrics';
+
+    /**
+     * Returns the column name of this metric, eg, `"nb_visits"` or `"avg_time_on_site"`.
+     *
+     * This string is what appears in API output.
+     *
+     * @return string
+     */
+    abstract public function getName();
+
+    /**
+     * Returns the human readable translated name of this metric, eg, `"Visits"` or `"Avg. time on site"`.
+     *
+     * This string is what appears in the UI.
+     *
+     * @return string
+     */
+    abstract public function getTranslatedName();
+
+    /**
+     * Returns a string describing what the metric represents. The result will be included in report metadata
+     * API output, including processed reports.
+     *
+     * Implementing this method is optional.
+     *
+     * @return string
+     */
+    public function getDocumentation()
+    {
+        return "";
+    }
+
+    /**
+     * Returns a formatted metric value. This value is what appears in API output. From within Piwik,
+     * (core & plugins) the computed value is used. Only when outputting to the API does a metric
+     * get formatted.
+     *
+     * By default, just returns the value.
+     *
+     * @param mixed $value The metric value.
+     * @param Formatter $formatter The formatter to use when formatting a value.
+     * @return mixed $value
+     */
+    public function format($value, Formatter $formatter)
+    {
+        return $value;
+    }
+
+    /**
+     * Executed before formatting all metrics for a report. Implementers can return `false`
+     * to skip formatting this metric and can use this method to access information needed for
+     * formatting (for example, the site ID).
+     *
+     * @param Report $report
+     * @param DataTable $table
+     * @return bool Return `true` to format the metric for the table, `false` to skip formatting.
+     */
+    public function beforeFormat($report, DataTable $table)
+    {
+        return true;
+    }
+
+    /**
+     * Helper method that will access a metric in a {@link Piwik\DataTable\Row} or array either by
+     * its name or by its special numerical index value.
+     *
+     * @param Row|array $row
+     * @param string $columnName
+     * @param int[]|null $mappingNameToId A custom mapping of metric names to special index values. By
+     *                                    default {@link Metrics::getMappingFromNameToId()} is used.
+     * @return mixed The metric value or false if none exists.
+     */
+    public static function getMetric($row, $columnName, $mappingNameToId = null)
+    {
+        if (empty($mappingNameToId)) {
+            $mappingNameToId = Metrics::getMappingFromNameToId();
+        }
+
+        if ($row instanceof Row) {
+            $value = $row->getColumn($columnName);
+            if ($value === false
+                && isset($mappingNameToId[$columnName])
+            ) {
+                $value = $row->getColumn($mappingNameToId[$columnName]);
+            }
+        } else {
+            $value = @$row[$columnName];
+            if ($value === null
+                && isset($mappingNameToId[$columnName])
+            ) {
+                $columnName = $mappingNameToId[$columnName];
+                $value = @$row[$columnName];
+            }
+            return $value;
+        }
+
+        return $value;
+    }
+
+    /**
+     * Helper method that will determine the actual column name for a metric in a
+     * {@link Piwik\DataTable} and return every column value for this name.
+     *
+     * @param DataTable $table
+     * @param string $columnName
+     * @param int[]|null $mappingNameToId A custom mapping of metric names to special index values. By
+     *                                    default {@link Metrics::getMappingFromNameToId()} is used.
+     * @return array
+     */
+    public static function getMetricValues(DataTable $table, $columnName, $mappingNameToId = null)
+    {
+        if (empty($mappingIdToName)) {
+            $mappingNameToId = Metrics::getMappingFromNameToId();
+        }
+
+        $columnName = self::getActualMetricColumn($table, $columnName, $mappingNameToId);
+        return $table->getColumn($columnName);
+    }
+
+    /**
+     * Helper method that determines the actual column for a metric in a {@link Piwik\DataTable}.
+     *
+     * @param DataTable $table
+     * @param string $columnName
+     * @param int[]|null $mappingNameToId A custom mapping of metric names to special index values. By
+     *                                    default {@link Metrics::getMappingFromNameToId()} is used.
+     * @return string
+     */
+    public static function getActualMetricColumn(DataTable $table, $columnName, $mappingNameToId = null)
+    {
+        if (empty($mappingIdToName)) {
+            $mappingNameToId = Metrics::getMappingFromNameToId();
+        }
+
+        $firstRow = $table->getFirstRow();
+        if (!empty($firstRow)
+            && $firstRow->getColumn($columnName) === false
+        ) {
+            $columnName = $mappingNameToId[$columnName];
+        }
+        return $columnName;
+    }
+}
\ No newline at end of file
diff --git a/core/Plugin/ProcessedMetric.php b/core/Plugin/ProcessedMetric.php
new file mode 100644
index 0000000000..20201d0887
--- /dev/null
+++ b/core/Plugin/ProcessedMetric.php
@@ -0,0 +1,70 @@
+<?php
+/**
+ * Piwik - free/libre analytics platform
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ */
+namespace Piwik\Plugin;
+
+use Piwik\DataTable;
+use Piwik\DataTable\Row;
+
+/**
+ * Base type for processed metrics. A processed metric is a metric that is computed using
+ * one or more other metrics.
+ *
+ * @api
+ */
+abstract class ProcessedMetric extends Metric
+{
+    /**
+     * The sub-namespace name in a plugin where ProcessedMetrics are stored.
+     */
+    const COMPONENT_SUBNAMESPACE = 'Columns\\Metrics';
+
+    /**
+     * Computes the metric using the values in a {@link Piwik\DataTable\Row}.
+     *
+     * The computed value should be numerical and not formatted in any way. For example, for
+     * a percent value, `0.14` should be returned instead of `"14%"`.
+     *
+     * @return mixed
+     */
+    abstract public function compute(Row $row);
+
+    /**
+     * Returns the array of metrics that are necessary for computing this metric. The elements
+     * of the array are metric names.
+     *
+     * @return string[]
+     */
+    abstract public function getDependentMetrics();
+
+    /**
+     * Returns the array of metrics that are necessary for computing this metric, but should not
+     * be displayed to the user unless explicitly requested. These metrics are intermediate
+     * metrics that are not really valuable to the user. On a request, if showColumns or hideColumns
+     * is not used, they will be removed automatically.
+     *
+     * @return string[]
+     */
+    public function getTemporaryMetrics()
+    {
+        return array();
+    }
+
+    /**
+     * Executed before computing all processed metrics for a report. Implementers can return `false`
+     * to skip computing this metric.
+     *
+     * @param Report $report
+     * @param DataTable $table
+     * @return bool Return `true` to compute the metric for the table, `false` to skip computing
+     *              this metric.
+     */
+    public function beforeCompute($report, DataTable $table)
+    {
+        return true;
+    }
+}
\ No newline at end of file
diff --git a/core/Plugin/Report.php b/core/Plugin/Report.php
index c30e731d46..1824b6774f 100644
--- a/core/Plugin/Report.php
+++ b/core/Plugin/Report.php
@@ -119,7 +119,7 @@ class Report
      * platform default processed metrics, see {@link Metrics::getDefaultProcessedMetrics()}. Set it to boolean `false`
      * if your report does not support any processed metrics at all. Otherwise an array of metric names.
      * Eg `array('avg_time_on_site', 'nb_actions_per_visit', ...)`
-     * @var array|false
+     * @var array
      * @api
      */
     protected $processedMetrics = array('nb_actions_per_visit', 'avg_time_on_site', 'bounce_rate', 'conversion_rate');
@@ -196,6 +196,7 @@ class Report
         'General_Visitors',
         'DevicesDetection_DevicesDetection',
         'UserSettings_VisitorSettings',
+        'API'
     );
 
     /**
@@ -359,6 +360,44 @@ class Report
     }
 
     /**
+     * Returns the list of metrics required at minimum for a report factoring in the columns requested by
+     * the report requester.
+     *
+     * This will return all the metrics requested (or all the metrics in the report if nothing is requested)
+     * **plus** the metrics required to calculate the requested processed metrics.
+     *
+     * This method should be used in **Plugin.get** API methods.
+     *
+     * @param string[]|null $allMetrics The list of all available unprocessed metrics. Defaults to this report's
+     *                                  metrics.
+     * @param string[]|null $restrictToColumns The requested columns.
+     * @return string[]
+     */
+    public function getMetricsRequiredForReport($allMetrics = null, $restrictToColumns = null)
+    {
+        if (empty($allMetrics)) {
+            $allMetrics = $this->metrics;
+        }
+
+        if (empty($restrictToColumns)) {
+            $restrictToColumns = array_merge($allMetrics, array_keys($this->getProcessedMetrics()));
+        }
+
+        $processedMetricsById = $this->getProcessedMetricsById();
+        $metricsSet = array_flip($allMetrics);
+
+        $metrics = array();
+        foreach ($restrictToColumns as $column) {
+            if (isset($processedMetricsById[$column])) {
+                $metrics = array_merge($metrics, $processedMetricsById[$column]->getDependentMetrics());
+            } else if (isset($metricsSet[$column])) {
+                $metrics[] = $column;
+            }
+        }
+        return array_unique($metrics);
+    }
+
+    /**
      * Returns an array of supported processed metrics and their corresponding translations. Eg
      * `array('nb_visits' => 'Visits')`. By default the given {@link $processedMetrics} are used and their
      * corresponding translations are looked up automatically. If a metric is not translated, you should add the
@@ -378,6 +417,18 @@ class Report
     }
 
     /**
+     * Returns the array of all metrics displayed by this report.
+     *
+     * @return array
+     * @api
+     */
+    public function getAllMetrics()
+    {
+        $processedMetrics = $this->getProcessedMetrics() ?: array();
+        return array_keys(array_merge($this->getMetrics(), $processedMetrics));
+    }
+
+    /**
      * Returns an array of metric documentations and their corresponding translations. Eg
      * `array('nb_visits' => 'If a visitor comes to your website for the first time or if he visits a page more than 30 minutes after...')`.
      * By default the given {@link $metrics} are used and their corresponding translations are looked up automatically.
@@ -399,6 +450,23 @@ class Report
             }
         }
 
+        $processedMetrics = $this->processedMetrics ?: array();
+        foreach ($processedMetrics as $processedMetric) {
+            if (!($processedMetric instanceof ProcessedMetric)) {
+                continue;
+            }
+
+            $name = $processedMetric->getName();
+            $metricDocs = $processedMetric->getDocumentation();
+            if (empty($metricDocs)) {
+                $metricDocs = @$translations[$name];
+            }
+
+            if (!empty($metricDocs)) {
+                $documentation[$processedMetric->getName()] = $metricDocs;
+            }
+        }
+
         return $documentation;
     }
 
@@ -666,7 +734,7 @@ class Report
      */
     public static function getAllReports()
     {
-        $reports = PluginManager::getInstance()->findMultipleComponents('Reports', '\\Piwik\\Plugin\\Report');
+        $reports = self::getAllReportClasses();
         $cache   = new LanguageAwareStaticCache('Reports' . implode('', $reports));
 
         if (!$cache->has()) {
@@ -685,6 +753,17 @@ class Report
     }
 
     /**
+     * Returns class names of all Report metadata classes.
+     *
+     * @return string[]
+     * @api
+     */
+    public static function getAllReportClasses()
+    {
+        return PluginManager::getInstance()->findMultipleComponents('Reports', '\\Piwik\\Plugin\\Report');
+    }
+
+    /**
      * API metadata are sorted by category/name,
      * with a little tweak to replicate the standard Piwik category ordering
      *
@@ -705,11 +784,15 @@ class Report
         $metrics = array();
 
         foreach ($metricsToTranslate as $metric) {
-            if (!empty($translations[$metric])) {
-                $metrics[$metric] = $translations[$metric];
+            if ($metric instanceof Metric) {
+                $metricName = $metric->getName();
+                $translation = $metric->getTranslatedName();
             } else {
-                $metrics[$metric] = $metric;
+                $metricName = $metric;
+                $translation = @$translations[$metric];
             }
+
+            $metrics[$metricName] = $translation ?: $metricName;
         }
 
         return $metrics;
@@ -738,10 +821,76 @@ class Report
      */
     public static function getForDimension(Dimension $dimension)
     {
-        return ComponentFactory::getComponentif (__CLASS__, $dimension->getModule(), function (Report $report) use ($dimension) {
+        return ComponentFactory::getComponentIf(__CLASS__, $dimension->getModule(), function (Report $report) use ($dimension) {
             return !$report->isSubtableReport()
                 && $report->getDimension()
                 && $report->getDimension()->getId() == $dimension->getId();
         });
     }
-}
+
+    /**
+     * Returns an array mapping the ProcessedMetrics served by this report by their string names.
+     *
+     * @return ProcessedMetric[]
+     */
+    public function getProcessedMetricsById()
+    {
+        $processedMetrics = $this->processedMetrics ?: array();
+
+        $result = array();
+        foreach ($processedMetrics as $processedMetric) {
+            if ($processedMetric instanceof ProcessedMetric) { // instanceof check for backwards compatibility
+                $result[$processedMetric->getName()] = $processedMetric;
+            }
+        }
+        return $result;
+    }
+
+    /**
+     * Returns the Metrics that are displayed by a DataTable of a certain Report type.
+     *
+     * Includes ProcessedMetrics and Metrics.
+     *
+     * @param DataTable $dataTable
+     * @param Report|null $report
+     * @param string $baseType The base type each metric class needs to be of.
+     * @return Metric[]
+     * @api
+     */
+    public static function getMetricsForTable(DataTable $dataTable, Report $report = null, $baseType = 'Piwik\\Plugin\\Metric')
+    {
+        $metrics = $dataTable->getMetadata(DataTable::EXTRA_PROCESSED_METRICS_METADATA_NAME) ?: array();
+
+        if (!empty($report)) {
+            $metrics = array_merge($metrics, $report->getProcessedMetricsById());
+        }
+
+        $result = array();
+
+        /** @var Metric $metric */
+        foreach ($metrics as $metric) {
+            if (!($metric instanceof $baseType)) {
+                continue;
+            }
+
+            $result[$metric->getName()] = $metric;
+        }
+
+        return $result;
+    }
+
+    /**
+     * Returns the ProcessedMetrics that should be computed and formatted for a DataTable of a
+     * certain report. The ProcessedMetrics returned are those specified by the Report metadata
+     * as well as the DataTable metadata.
+     *
+     * @param DataTable $dataTable
+     * @param Report|null $report
+     * @return ProcessedMetric[]
+     * @api
+     */
+    public static function getProcessedMetricsForTable(DataTable $dataTable, Report $report = null)
+    {
+        return self::getMetricsForTable($dataTable, $report, 'Piwik\\Plugin\\ProcessedMetric');
+    }
+}
\ No newline at end of file
diff --git a/core/Plugin/Visualization.php b/core/Plugin/Visualization.php
index 938bcb7a4d..7e6aec2eaa 100644
--- a/core/Plugin/Visualization.php
+++ b/core/Plugin/Visualization.php
@@ -9,11 +9,12 @@
 
 namespace Piwik\Plugin;
 
+use Piwik\API\DataTablePostProcessor;
 use Piwik\Common;
 use Piwik\DataTable;
 use Piwik\Date;
 use Piwik\Log;
-use Piwik\MetricsFormatter;
+use Piwik\Metrics\Formatter\Html as HtmlFormatter;
 use Piwik\NoAccessException;
 use Piwik\Option;
 use Piwik\Period;
@@ -143,6 +144,12 @@ class Visualization extends ViewDataTable
     private $templateVars = array();
     private $reportLastUpdatedMessage = null;
     private $metadata = null;
+    protected $metricsFormatter = null;
+
+    /**
+     * @var Report
+     */
+    protected $report;
 
     final public function __construct($controllerAction, $apiMethodToRequestDataTable, $params = array())
     {
@@ -152,7 +159,11 @@ class Visualization extends ViewDataTable
             throw new \Exception('You have not defined a constant named TEMPLATE_FILE in your visualization class.');
         }
 
+        $this->metricsFormatter = new HtmlFormatter();
+
         parent::__construct($controllerAction, $apiMethodToRequestDataTable, $params);
+
+        $this->report = Report::factory($this->requestConfig->getApiModuleToRequest(), $this->requestConfig->getApiMethodToRequest());
     }
 
     protected function buildView()
@@ -160,20 +171,19 @@ class Visualization extends ViewDataTable
         $this->overrideSomeConfigPropertiesIfNeeded();
 
         try {
-
             $this->beforeLoadDataTable();
 
-            $this->loadDataTableFromAPI(array('disable_generic_filters' => 1));
+            $this->loadDataTableFromAPI(array('disable_generic_filters' => 1, 'format_metrics' => 0));
             $this->postDataTableLoadedFromAPI();
 
             $requestPropertiesAfterLoadDataTable = $this->requestConfig->getProperties();
 
             $this->applyFilters();
+            $this->addVisualizationInfoFromMetricMetadata();
             $this->afterAllFiltersAreApplied();
             $this->beforeRender();
 
             $this->logMessageIfRequestPropertiesHaveChanged($requestPropertiesAfterLoadDataTable);
-
         } catch (NoAccessException $e) {
             throw $e;
         } catch (\Exception $e) {
@@ -306,6 +316,27 @@ class Visualization extends ViewDataTable
         }
     }
 
+    private function addVisualizationInfoFromMetricMetadata()
+    {
+        $dataTable = $this->dataTable instanceof DataTable\Map ? $this->dataTable->getFirstRow() : $this->dataTable;
+
+        $metrics = Report::getMetricsForTable($dataTable, $this->report);
+
+        // TODO: instead of iterating & calling translate everywhere, maybe we can get all translated names in one place.
+        //       may be difficult, though, since translated metrics are specific to the report.
+        foreach ($metrics as $metric) {
+            $name = $metric->getName();
+
+            if (empty($this->config->translations[$name])) {
+                $this->config->translations[$name] = $metric->getTranslatedName();
+            }
+
+            if (empty($this->config->metrics_documentation[$name])) {
+                $this->config->metrics_documentation[$name] = $metric->getDocumentation();
+            }
+        }
+    }
+
     private function applyFilters()
     {
         list($priorityFilters, $otherFilters) = $this->config->getFiltersToRun();
@@ -322,10 +353,14 @@ class Visualization extends ViewDataTable
             $this->requestConfig->setDefaultSort($this->config->columns_to_display, $hasNbUniqVisitors, $this->dataTable->getColumns());
         }
 
+        $postProcessor = $this->makeDataTablePostProcessor(); // must be created after requestConfig is final
+
         if (!$this->requestConfig->areGenericFiltersDisabled()) {
-            $this->applyGenericFilters();
+            $this->dataTable = $postProcessor->applyGenericFilters($this->dataTable);
         }
 
+        $postProcessor->applyComputeProcessedMetrics($this->dataTable);
+
         $this->afterGenericFiltersAreAppliedToLoadedDataTable();
 
         // queue other filters so they can be applied later if queued filters are disabled
@@ -338,6 +373,12 @@ class Visualization extends ViewDataTable
         if (!$this->requestConfig->areQueuedFiltersDisabled()) {
             $this->dataTable->applyQueuedFilters();
         }
+
+        $formatter = $this->metricsFormatter;
+        $report = $this->report;
+        $this->dataTable->filter(function (DataTable $table) use ($formatter, $report) {
+            $formatter->formatMetrics($table, $report);
+        });
     }
 
     private function removeEmptyColumnsFromDisplay()
@@ -372,9 +413,8 @@ class Visualization extends ViewDataTable
         $today    = mktime(0, 0, 0);
 
         if ($date->getTimestamp() > $today) {
-
             $elapsedSeconds = time() - $date->getTimestamp();
-            $timeAgo        = MetricsFormatter::getPrettyTimeFromSeconds($elapsedSeconds);
+            $timeAgo        = $this->metricsFormatter->getPrettyTimeFromSeconds($elapsedSeconds);
 
             return Piwik::translate('CoreHome_ReportGeneratedXAgo', $timeAgo);
         }
@@ -567,10 +607,7 @@ class Visualization extends ViewDataTable
         // eg $this->config->showFooterColumns = true;
     }
 
-    /**
-     * Second, generic filters (Sort, Limit, Replace Column Names, etc.)
-     */
-    private function applyGenericFilters()
+    private function makeDataTablePostProcessor()
     {
         $requestArray = $this->request->getRequestArray();
         $request      = \Piwik\API\Request::getRequestArrayFromString($requestArray);
@@ -580,8 +617,7 @@ class Visualization extends ViewDataTable
             $request['filter_sort_order']  = '';
         }
 
-        $genericFilter = new \Piwik\API\DataTableGenericFilter($request);
-        $genericFilter->filter($this->dataTable);
+        return new DataTablePostProcessor($this->requestConfig->getApiModuleToRequest(), $this->requestConfig->getApiMethodToRequest(), $request);
     }
 
     private function logMessageIfRequestPropertiesHaveChanged(array $requestPropertiesBefore)
diff --git a/core/Session.php b/core/Session.php
index d55d399bbe..a002243f70 100644
--- a/core/Session.php
+++ b/core/Session.php
@@ -121,7 +121,7 @@ class Session extends Zend_Session
             $enableDbSessions = '';
             if (DbHelper::isInstalled()) {
                 $enableDbSessions = "<br/>If you still experience issues after trying these changes,
-			            			we recommend that you <a href='http://piwik.org/faq/how-to-install/#faq_133' target='_blank'>enable database session storage</a>.";
+			            			we recommend that you <a href='http://piwik.org/faq/how-to-install/#faq_133' rel='noreferrer' target='_blank'>enable database session storage</a>.";
             }
 
             $pathToSessions = Filechecks::getErrorMessageMissingPermissions(Filesystem::getPathToPiwikRoot() . '/tmp/sessions/');
diff --git a/core/Timer.php b/core/Timer.php
index 82addaa1cd..c7401677bf 100644
--- a/core/Timer.php
+++ b/core/Timer.php
@@ -7,6 +7,7 @@
  *
  */
 namespace Piwik;
+use Piwik\Metrics\Formatter;
 
 /**
  *
@@ -15,12 +16,15 @@ class Timer
 {
     private $timerStart;
     private $memoryStart;
+    private $formatter;
 
     /**
      * @return \Piwik\Timer
      */
     public function __construct()
     {
+        $this->formatter = new Formatter();
+
         $this->init();
     }
 
@@ -56,7 +60,7 @@ class Timer
      */
     public function getMemoryLeak()
     {
-        return "Memory delta: " . MetricsFormatter::getPrettySizeFromBytes($this->getMemoryUsage() - $this->memoryStart);
+        return "Memory delta: " . $this->formatter->getPrettySizeFromBytes($this->getMemoryUsage() - $this->memoryStart);
     }
 
     /**
diff --git a/core/Twig.php b/core/Twig.php
index 1ce277e235..1127d47a60 100755
--- a/core/Twig.php
+++ b/core/Twig.php
@@ -11,6 +11,7 @@ namespace Piwik;
 use Exception;
 use Piwik\Container\StaticContainer;
 use Piwik\DataTable\Filter\SafeDecodeLabel;
+use Piwik\Metrics\Formatter;
 use Piwik\Translate;
 use Piwik\View\RenderTokenParser;
 use Piwik\Visualization\Sparkline;
@@ -35,6 +36,8 @@ class Twig
      */
     private $twig;
 
+    private $formatter;
+
     public function __construct()
     {
         $loader = $this->getDefaultThemeLoader();
@@ -45,6 +48,8 @@ class Twig
 		$theme   = $manager->getThemeEnabled();
 		$loaders = array();
 
+        $this->formatter = new Formatter();
+
 		//create loader for custom theme to overwrite twig templates
 		if ($theme && $theme->getPluginName() != \Piwik\Plugin\Manager::DEFAULT_THEME) {
 			$customLoader = $this->getCustomThemeLoader($theme);
@@ -272,21 +277,23 @@ class Twig
 
     protected function addFilter_money()
     {
-        $moneyFilter = new Twig_SimpleFilter('money', function ($amount) {
+        $formatter = $this->formatter;
+        $moneyFilter = new Twig_SimpleFilter('money', function ($amount) use ($formatter) {
             if (func_num_args() != 2) {
                 throw new Exception('the money modifier expects one parameter: the idSite.');
             }
             $idSite = func_get_args();
             $idSite = $idSite[1];
-            return MetricsFormatter::getPrettyMoney($amount, $idSite);
+            return $formatter->getPrettyMoney($amount, $idSite);
         });
         $this->twig->addFilter($moneyFilter);
     }
 
     protected function addFilter_sumTime()
     {
-        $sumtimeFilter = new Twig_SimpleFilter('sumtime', function ($numberOfSeconds) {
-            return MetricsFormatter::getPrettyTimeFromSeconds($numberOfSeconds);
+        $formatter = $this->formatter;
+        $sumtimeFilter = new Twig_SimpleFilter('sumtime', function ($numberOfSeconds) use ($formatter) {
+            return $formatter->getPrettyTimeFromSeconds($numberOfSeconds, true);
         });
         $this->twig->addFilter($sumtimeFilter);
     }
diff --git a/core/Updates/0.6-rc1.php b/core/Updates/0.6-rc1.php
index 9f293dda97..9a946251ad 100644
--- a/core/Updates/0.6-rc1.php
+++ b/core/Updates/0.6-rc1.php
@@ -42,8 +42,8 @@ class Updates_0_6_rc1 extends Updates
     {
         // first we disable the plugins and keep an array of warnings messages
         $pluginsToDisableMessage = array(
-            'SearchEnginePosition' => "SearchEnginePosition plugin was disabled, because it is not compatible with the new Piwik 0.6. \n You can download the latest version of the plugin, compatible with Piwik 0.6.\n<a target='_blank' href='?module=Proxy&action=redirect&url=https://github.com/piwik/piwik/issues/502'>Click here.</a>",
-            'GeoIP'                => "GeoIP plugin was disabled, because it is not compatible with the new Piwik 0.6. \nYou can download the latest version of the plugin, compatible with Piwik 0.6.\n<a target='_blank' href='?module=Proxy&action=redirect&url=https://github.com/piwik/piwik/issues/45'>Click here.</a>"
+            'SearchEnginePosition' => "SearchEnginePosition plugin was disabled, because it is not compatible with the new Piwik 0.6. \n You can download the latest version of the plugin, compatible with Piwik 0.6.\n<a rel='noreferrer' target='_blank' href='?module=Proxy&action=redirect&url=https://github.com/piwik/piwik/issues/502'>Click here.</a>",
+            'GeoIP'                => "GeoIP plugin was disabled, because it is not compatible with the new Piwik 0.6. \nYou can download the latest version of the plugin, compatible with Piwik 0.6.\n<a rel='noreferrer' target='_blank' href='?module=Proxy&action=redirect&url=https://github.com/piwik/piwik/issues/45'>Click here.</a>"
         );
         $disabledPlugins = array();
         foreach ($pluginsToDisableMessage as $pluginToDisable => $warningMessage) {
diff --git a/core/Updates/1.2-rc1.php b/core/Updates/1.2-rc1.php
index e268ad8570..658dffeb27 100644
--- a/core/Updates/1.2-rc1.php
+++ b/core/Updates/1.2-rc1.php
@@ -129,7 +129,7 @@ class Updates_1_2_rc1 extends Updates
     {
         // first we disable the plugins and keep an array of warnings messages
         $pluginsToDisableMessage = array(
-            'GeoIP'     => "GeoIP plugin was disabled, because it is not compatible with the new Piwik 1.2. \nYou can download the latest version of the plugin, compatible with Piwik 1.2.\n<a target='_blank' href='?module=Proxy&action=redirect&url=https://github.com/piwik/piwik/issues/45'>Click here.</a>",
+            'GeoIP'     => "GeoIP plugin was disabled, because it is not compatible with the new Piwik 1.2. \nYou can download the latest version of the plugin, compatible with Piwik 1.2.\n<a rel='noreferrer' target='_blank' href='?module=Proxy&action=redirect&url=https://github.com/piwik/piwik/issues/45'>Click here.</a>",
             'EntryPage' => "EntryPage plugin is not compatible with this version of Piwik, it was disabled.",
         );
         $disabledPlugins = array();
diff --git a/core/testMinimumPhpVersion.php b/core/testMinimumPhpVersion.php
index a24780077d..eec5a50d1b 100644
--- a/core/testMinimumPhpVersion.php
+++ b/core/testMinimumPhpVersion.php
@@ -52,11 +52,11 @@ if ($minimumPhpInvalid) {
             $composerInstall = "Download and run <a href=\"https://getcomposer.org/Composer-Setup.exe\"><b>Composer-Setup.exe</b></a>, it will install the latest Composer version and set up your PATH so that you can just call composer from any directory in your command line. "
                 . " <br>Then run this command in a terminal in the piwik directory: <br> $ php composer.phar update ";
         }
-        $piwik_errorMessage .= "<p>It appears the <a href='https://getcomposer.org/' target='_blank'>composer</a> tool is not yet installed. You can install Composer in a few easy steps:\n\n".
+        $piwik_errorMessage .= "<p>It appears the <a href='https://getcomposer.org/' rel='noreferrer' target='_blank'>composer</a> tool is not yet installed. You can install Composer in a few easy steps:\n\n".
                     "<br/>" . $composerInstall.
                     " This will initialize composer for Piwik and download libraries we use in vendor/* directory.".
                     "\n\n<br/><br/>Then reload this page to access your analytics reports." .
-                    "\n\n<br/><br/>For more information check out this FAQ: <a href='http://piwik.org/faq/how-to-install/faq_18271/' target='_blank'>How do I use Piwik from the Git repository?</a>." .
+                    "\n\n<br/><br/>For more information check out this FAQ: <a href='http://piwik.org/faq/how-to-install/faq_18271/' rel='noreferrer' target='_blank'>How do I use Piwik from the Git repository?</a>." .
                     "\n\n<br/><br/>Note: if for some reasons you cannot install composer, instead install the latest Piwik release from ".
                     "<a href='http://builds.piwik.org/piwik.zip'>builds.piwik.org</a>.</p>";
     }
@@ -122,11 +122,11 @@ if (!function_exists('Piwik_GetErrorMessagePage')) {
 
         if ($optionalLinks) {
             $optionalLinks = '<ul>
-                            <li><a target="_blank" href="http://piwik.org">Piwik.org homepage</a></li>
-                            <li><a target="_blank" href="http://piwik.org/faq/">Piwik Frequently Asked Questions</a></li>
-                            <li><a target="_blank" href="http://piwik.org/docs/">Piwik Documentation</a></li>
-                            <li><a target="_blank" href="http://forum.piwik.org/">Piwik Forums</a></li>
-                            <li><a target="_blank" href="http://demo.piwik.org">Piwik Online Demo</a></li>
+                            <li><a rel="noreferrer" target="_blank" href="http://piwik.org">Piwik.org homepage</a></li>
+                            <li><a rel="noreferrer" target="_blank" href="http://piwik.org/faq/">Piwik Frequently Asked Questions</a></li>
+                            <li><a rel="noreferrer" target="_blank" href="http://piwik.org/docs/">Piwik Documentation</a></li>
+                            <li><a rel="noreferrer" target="_blank" href="http://forum.piwik.org/">Piwik Forums</a></li>
+                            <li><a rel="noreferrer" target="_blank" href="http://demo.piwik.org">Piwik Online Demo</a></li>
                             </ul>';
         }
         if ($optionalLinkBack) {