1 files changed, 19 insertions, 0 deletions
diff --git a/app/controllers/concerns/markdown_preview.rb b/app/controllers/concerns/markdown_preview.rb
new file mode 100644
index 00000000000..40eff267348
--- /dev/null
+++ b/app/controllers/concerns/markdown_preview.rb
@@ -0,0 +1,19 @@
+module MarkdownPreview
+  private
+
+  def render_markdown_preview(text, markdown_context = {})
+    render json: {
+      body: view_context.markdown(text, markdown_context),
+      references: {
+        users: preview_referenced_users(text)
+      }
+    }
+  end
+
+  def preview_referenced_users(text)
+    extractor = Gitlab::ReferenceExtractor.new(@project, current_user)
+    extractor.analyze(text, author: current_user)
+
+    extractor.users.map(&:username)
+  end
+end