add app helper

.autotest

@@ -2,4 +2,12 @@ Autotest.add_hook(:initialize) do |at|
   at.add_mapping(%r{bin/(.*)}, true) do |filename, matches|
     at.files_matching(%r{spec/bin/#{matches[1]}_spec\.rb})
   end
+
+  at.add_mapping(%r{spec/(.*)}, true) do |filename, matches|
+    at.files_matching(%r{#{filename}})
+  end
+
+  at.add_mapping(%r{templates/.*}, true) do |filename, matches|
+    at.files_matching(%r{spec/bin/.*_spec\.rb})
+  end
 end

bin/backbone-generator

@@ -86,6 +86,11 @@ class BackboneGenerator < Thor
     template('spec_helper.js.erb', 'spec/javascripts/helpers/backbone_spec_helper.js')
   end
 
+  desc 'app-helper', "Generate an application helper for useful Backbone things"
+  def app_helper
+    template('app_helper.js.erb', 'public/javascripts/applications/backbone_helper.js')
+  end
+
   private
   def pluralize(string)
     singularize(string) + 's'

spec/bin/backbone-generator_spec.rb

@@ -125,4 +125,12 @@ describe 'backbone-generator' do
       File.file?(collection = 'spec/javascripts/helpers/backbone_spec_helper.js').should be_true
     end
   end
+
+  describe 'app helper' do
+    it "should generate an app helper" do
+      system %{bin/backbone-generator app-helper}
+
+      File.file?(collection = 'public/javascripts/applications/backbone_helper.js').should be_true
+    end
+  end
 end

templates/app_helper.js.erb

@@ -0,0 +1,19 @@
+/* Ensure a Collection is fetched and has entries before running a block of code. */
+
+_.extend(Backbone.Collection.prototype, {
+  ensureFetched: function(callback) {
+    if (this.length == 0 || this._alreadyEnsureFetched) {
+      var _this = this;
+      var _refresher = function() {
+        _this.unbind('refresh', _refresher);
+        callback.apply(_this);
+        _this._alreadyEnsureFetched = true;
+      };
+      this.bind('refresh', _refresher);
+      this.fetch();
+    } else {
+      callback.apply(this);
+    }
+  }
+});
+