Add indexer service (equivalent of Dereferencer, but named more accurately)

app/assets/javascripts/admin/services/indexer.js.coffee

@@ -0,0 +1,13 @@
+# Convert an array of objects into a hash, indexed by the objects' ids
+#
+# producers = [{id: 1, name: 'one'}, {id: 2, name: 'two'}]
+# Indexer.index producers
+# -> {1: {id: 1, name: 'one'}, 2: {id: 2, name: 'two'}}
+
+angular.module("ofn.admin").factory 'Indexer', ->
+  new class Indexer
+    index: (data) ->
+      index = []
+      for e in data
+        index[e.id] = e
+      index