Wrap images in discussions and wikis with a link to the image source using ImageLinkFilter.

Resolves #14411.

See merge request !3464

2 files changed, 28 insertions, 0 deletions

diff --git a/lib/banzai/filter/image_link_filter.rb b/lib/banzai/filter/image_link_filter.rb
new file mode 100644
index 00000000000..ccd106860bd
--- /dev/null
+++ b/lib/banzai/filter/image_link_filter.rb
@@ -0,0 +1,27 @@
+module Banzai
+  module Filter
+    # HTML filter that wraps links around inline images.
+    class ImageLinkFilter < HTML::Pipeline::Filter
+      
+      # Find every image that isn't already wrapped in an `a` tag, create
+      # a new node (a link to the image source), copy the image as a child
+      # of the anchor, and then replace the img with the link-wrapped version.
+      def call
+        doc.xpath('descendant-or-self::img[not(ancestor::a)]').each do |img|
+
+          link = doc.document.create_element(
+            'a',
+            class: 'no-attachment-icon',
+            href: img['src'],
+            target: '_blank'
+          )
+
+          link.children = img.clone
+          img.replace(link)
+        end
+
+        doc
+      end
+    end
+  end
+end
diff --git a/lib/banzai/pipeline/gfm_pipeline.rb b/lib/banzai/pipeline/gfm_pipeline.rb
index 8cd4b50e65a..ed3cfd6b023 100644
--- a/lib/banzai/pipeline/gfm_pipeline.rb
+++ b/lib/banzai/pipeline/gfm_pipeline.rb
@@ -7,6 +7,7 @@ module Banzai
           Filter::SanitizationFilter,
 
           Filter::UploadLinkFilter,
+          Filter::ImageLinkFilter,
           Filter::EmojiFilter,
           Filter::TableOfContentsFilter,
           Filter::AutolinkFilter,