1 files changed, 26 insertions, 0 deletions
diff --git a/lib/gitlab/markdown/cross_project_reference.rb b/lib/gitlab/markdown/cross_project_reference.rb
new file mode 100644
index 00000000000..114247d0a33
--- /dev/null
+++ b/lib/gitlab/markdown/cross_project_reference.rb
@@ -0,0 +1,26 @@
+module Gitlab
+  module Markdown
+    # Includes shared code for reference filters that support an optional
+    # cross-project reference.
+    module CrossProjectReference
+      NAMING_PATTERN  = Gitlab::Regex::NAMESPACE_REGEX_STR
+      PROJECT_PATTERN = "(?<project>#{NAMING_PATTERN}/#{NAMING_PATTERN})"
+
+      # Given a cross-project reference string, get the Project record
+      #
+      # If no valid reference is given, returns the `:project` value for the
+      # current context.
+      #
+      # ref - String reference.
+      #
+      # Returns a Project
+      def project_from_ref(ref)
+        if ref && other = Project.find_with_namespace(ref)
+          other
+        else
+          context[:project]
+        end
+      end
+    end
+  end
+end