Two small changes for GA importer (#14727)

* Add ignored Visualization.beforeRender event.

* When creating datatables from blob rows, keep any existing metadata instead of overwriting everything.

* Add some docs to the new event.

* Update changelog.

2 files changed, 18 insertions, 5 deletions

diff --git a/core/Archive/DataTableFactory.php b/core/Archive/DataTableFactory.php
index 9c7deef31f..d46fb14a6e 100644
--- a/core/Archive/DataTableFactory.php
+++ b/core/Archive/DataTableFactory.php
@@ -271,7 +271,7 @@ class DataTableFactory
         }
 
         // set table metadata
-        $table->setAllTableMetadata(array_merge(DataCollection::getDataRowMetadata($blobRow), $keyMetadata));
+        $table->setAllTableMetadata(array_merge($table->getAllTableMetadata(), DataCollection::getDataRowMetadata($blobRow), $keyMetadata));
 
         if ($this->expandDataTable) {
             $table->enableRecursiveFilters();
@@ -297,7 +297,7 @@ class DataTableFactory
 
         foreach ($blobRow as $name => $blob) {
             $newTable = DataTable::fromSerializedArray($blob);
-            $newTable->setAllTableMetadata($tableMetadata);
+            $newTable->setAllTableMetadata(array_merge($newTable->getAllTableMetadata(), $tableMetadata));
 
             $table->addTable($newTable, $name);
         }
@@ -452,7 +452,7 @@ class DataTableFactory
         $table = new DataTable\Simple();
 
         if (!empty($data)) {
-            $table->setAllTableMetadata(array_merge(DataCollection::getDataRowMetadata($data), $keyMetadata));
+            $table->setAllTableMetadata(array_merge($table->getAllTableMetadata(), DataCollection::getDataRowMetadata($data), $keyMetadata));
 
             DataCollection::removeMetadataFromDataRow($data);
 
@@ -470,7 +470,7 @@ class DataTableFactory
                 $table->addRow(new Row(array(Row::COLUMNS => array($name => 0))));
             }
 
-            $table->setAllTableMetadata($keyMetadata);
+            $table->setAllTableMetadata(array_merge($table->getAllTableMetadata(), $keyMetadata));
         }
 
         $result = $table;
@@ -496,7 +496,7 @@ class DataTableFactory
                 $table = new DataTable();
             }
 
-            $table->setAllTableMetadata($metadata);
+            $table->setAllTableMetadata(array_merge($table->getAllTableMetadata(), $metadata));
             $map->addTable($table, $this->prettifyIndexLabel(self::TABLE_METADATA_PERIOD_INDEX, $range));
 
             $tables[$range] = $table;
diff --git a/core/Plugin/Visualization.php b/core/Plugin/Visualization.php
index b130f3c28e..e3a8b51bb1 100644
--- a/core/Plugin/Visualization.php
+++ b/core/Plugin/Visualization.php
@@ -190,7 +190,9 @@ class Visualization extends ViewDataTable
             $this->applyFilters();
             $this->addVisualizationInfoFromMetricMetadata();
             $this->afterAllFiltersAreApplied();
+
             $this->beforeRender();
+            $this->fireBeforeRenderHook();
 
             $this->logMessageIfRequestPropertiesHaveChanged($requestPropertiesAfterLoadDataTable);
         } catch (NoAccessException $e) {
@@ -723,6 +725,17 @@ class Visualization extends ViewDataTable
         // eg $this->config->showFooterColumns = true;
     }
 
+    private function fireBeforeRenderHook()
+    {
+        /**
+         * Posted immediately before rendering the view. Plugins can use this event to perform last minute
+         * configuration of the view based on it's data or the report being viewed.
+         *
+         * @param Visualization $view The instance to configure.
+         */
+        Piwik::postEvent('Visualization.beforeRender', [$this]);
+    }
+
     private function makeDataTablePostProcessor()
     {
         $request = $this->buildApiRequestArray();