Add `to_reference` for models that support references

Now there is a single source of information for which attribute a model
uses to be referenced, and its special character.

1 files changed, 17 insertions, 2 deletions

diff --git a/app/models/snippet.rb b/app/models/snippet.rb
index d2af26539b6..90fada3c114 100644
--- a/app/models/snippet.rb
+++ b/app/models/snippet.rb
@@ -16,10 +16,11 @@
 #
 
 class Snippet < ActiveRecord::Base
-  include Sortable
-  include Linguist::BlobHelper
   include Gitlab::VisibilityLevel
+  include Linguist::BlobHelper
   include Participable
+  include Referable
+  include Sortable
 
   default_value_for :visibility_level, Snippet::PRIVATE
 
@@ -50,6 +51,20 @@ class Snippet < ActiveRecord::Base
 
   participant :author, :notes
 
+  def self.reference_prefix
+    '$'
+  end
+
+  def to_reference(from_project = nil)
+    reference = "#{self.class.reference_prefix}#{id}"
+
+    if cross_project_reference?(from_project)
+      reference = project.to_reference + reference
+    end
+
+    reference
+  end
+
   def self.content_types
     [
       ".rb", ".py", ".pl", ".scala", ".c", ".cpp", ".java",