Handle AsciiDoc better, reuse HTML pipeline filters (fixes #9263)

1 files changed, 60 insertions, 0 deletions

diff --git a/lib/gitlab/asciidoc.rb b/lib/gitlab/asciidoc.rb
new file mode 100644
index 00000000000..bf33e5b1b1e
--- /dev/null
+++ b/lib/gitlab/asciidoc.rb
@@ -0,0 +1,60 @@
+require 'asciidoctor'
+require 'html/pipeline'
+
+module Gitlab
+  # Parser/renderer for the AsciiDoc format that uses Asciidoctor and filters
+  # the resulting HTML through HTML pipeline filters.
+  module Asciidoc
+
+    # Provide autoload paths for filters to prevent a circular dependency error
+    autoload :RelativeLinkFilter, 'gitlab/markdown/relative_link_filter'
+
+    DEFAULT_ADOC_ATTRS = [
+      'showtitle', 'idprefix=user-content-', 'idseparator=-', 'env=gitlab',
+      'env-gitlab', 'source-highlighter=html-pipeline'
+    ].freeze
+
+    # Public: Converts the provided Asciidoc markup into HTML.
+    #
+    # input         - the source text in Asciidoc format
+    # context       - a Hash with the template context:
+    #                 :commit
+    #                 :project
+    #                 :project_wiki
+    #                 :requested_path
+    #                 :ref
+    # asciidoc_opts - a Hash of options to pass to the Asciidoctor converter
+    # html_opts     - a Hash of options for HTML output:
+    #                 :xhtml - output XHTML instead of HTML
+    #
+    def self.render(input, context, asciidoc_opts = {}, html_opts = {})
+      asciidoc_opts = asciidoc_opts.reverse_merge(
+        safe: :secure,
+        backend: html_opts[:xhtml] ? :xhtml5 : :html5,
+        attributes: []
+      )
+      asciidoc_opts[:attributes].unshift(*DEFAULT_ADOC_ATTRS)
+
+      html = ::Asciidoctor.convert(input, asciidoc_opts)
+
+      if context[:project]
+        result = HTML::Pipeline.new(filters).call(html, context)
+
+        save_opts = html_opts[:xhtml] ?
+          Nokogiri::XML::Node::SaveOptions::AS_XHTML : 0
+
+        html = result[:output].to_html(save_with: save_opts)
+      end
+
+      html.html_safe
+    end
+
+    private
+
+    def self.filters
+      [
+        Gitlab::Markdown::RelativeLinkFilter
+      ]
+    end
+  end
+end