Set the URL on the collection instead of the model.

cms/static/coffee/spec/models/asset_spec.coffee

-describe "CMS.Models.Asset", ->
-    beforeEach ->
-        CMS.URL.UPDATE_ASSET = "/update_asset/"
-        @model = new CMS.Models.Asset({id: "/c4x/id"})
-
-    afterEach ->
-        delete CMS.URL.UPDATE_ASSET
-
-    it "should have a url set", ->
-        expect(@model.url()).toEqual("/update_asset//c4x/id")
-

cms/static/coffee/spec/views/assets_spec.coffee

@@ -9,6 +9,7 @@ describe "CMS.Views.Asset", ->
         @model = new CMS.Models.Asset({display_name: "test asset", url: 'actual_asset_url', portable_url: 'portable_url', date_added: 'date', thumbnail: null, id: 'id'})
         spyOn(@model, "destroy").andCallThrough()
         @collection = new CMS.Models.AssetCollection([@model])
+        @collection.url = "update-asset-url"
         @view = new CMS.Views.Asset({model: @model})
 
         @promptSpies = spyOnConstructor(CMS.Views.Prompt, "Warning", ["show", "hide"])
@@ -82,6 +83,7 @@ describe "CMS.Views.Assets", ->
                 {display_name: "test asset 1", url: 'actual_asset_url_1', portable_url: 'portable_url_1', date_added: 'date_1', thumbnail: null, id: 'id_1'},
                 {display_name: "test asset 2", url: 'actual_asset_url_2', portable_url: 'portable_url_2', date_added: 'date_2', thumbnail: null, id: 'id_2'}
             ])
+        @collection.url = "update-asset-url"
         @view = new CMS.Views.Assets({collection: @collection, el: $('#asset_table_body')})
 
         @promptSpies = spyOnConstructor(CMS.Views.Prompt, "Warning", ["show", "hide"])

cms/static/js/models/asset.js

@@ -9,9 +9,5 @@ CMS.Models.Asset = Backbone.Model.extend({
         url: "",
         portable_url: "",
         is_locked: false
-    },
-
-    url: function() {
-        return CMS.URL.UPDATE_ASSET + this.id;
     }
 });

cms/templates/asset_index.html

@@ -18,8 +18,8 @@
     <script src="${static.url('js/vendor/jQuery-File-Upload/js/jquery.fileupload.js')}"> </script>
 
     <script type="text/javascript">
-        CMS.URL.UPDATE_ASSET = "${update_asset_callback_url}";
         var assets = new CMS.Models.AssetCollection(${asset_list});
+        assets.url = "${update_asset_callback_url}";
         var assetsView = new CMS.Views.Assets({collection: assets, el: $('#asset_table_body')});
 
         $(document).ready(function() {