Simplify the bridge service

 - Remove unused support for options
 - Simplify the handling of scope
 - Make it a simpleton, and register the class as the constructor function.

Also updated all tests.

Kudos to @tilgovi for the feedback and ideas.

h/static/scripts/annotator/plugin/cross-frame.coffee

@@ -20,8 +20,7 @@ CrossFrame = class Annotator.Plugin.CrossFrame extends Annotator.Plugin
     opts = extract(options, 'server')
     discovery = new CrossFrame.Discovery(window, opts)
 
-    opts = extract(options, 'scope')
-    bridge = new CrossFrame.Bridge(opts)
+    bridge = new CrossFrame.Bridge()
 
     opts = extract(options, 'on', 'emit', 'formatter', 'parser')
     annotationSync = new CrossFrame.AnnotationSync(bridge, opts)

h/static/scripts/annotator/plugin/test/cross-frame-test.coffee

@@ -51,10 +51,6 @@ describe 'Annotator.Plugin.CrossFrame', ->
       createCrossFrame()
       assert.calledWith(cf.CrossFrame.Discovery)
 
-    it 'passes the options along to the bridge', ->
-      createCrossFrame(scope: 'myscope')
-      assert.calledWith(cf.CrossFrame.Bridge, scope: 'myscope')
-
     it 'instantiates the AnnotationSync component', ->
       createCrossFrame()
       assert.called(cf.CrossFrame.AnnotationSync)

h/static/scripts/bridge.coffee

 $ = require('jquery')
 Channel = require('jschannel')
 
+# The Bridge service sets up a channel between frames
+# and provides an events API on top of it.
 class Bridge
-  options:
-    # Scope identifier to distinguish this channel from any others
-    scope: 'bridge'
-
-    # Callback to invoke when a connection is established. The function is
-    # passed:
-    # - the newly created channel object
-    # - the window just connected to
-    onConnect: null
-
-    # Any callbacks for messages on the channel. Max one callback per method.
-    channelListeners: null
-
   # Connected links to other frames
   links: null
   channelListeners: null
   onConnectListeners: null
 
-  constructor: (options) ->
-    @options = $.extend(true, {}, @options, options)
+  constructor: ->
     @links = []
-    @channelListeners = @options.channelListeners || {}
+    @channelListeners = {}
     @onConnectListeners = []
-    if typeof @options.onConnect == 'function'
-      @onConnectListeners.push(@options.onConnect)
 
-  createChannel: (source, origin, token) ->
+  createChannel: (source, origin, scope) ->
     # Set up a channel
-    scope = @options.scope + ':' + token
     channelOptions =
       window: source
       origin: origin
@@ -119,6 +104,6 @@ class Bridge
     channel = Channel.build(options)
 
 if angular?
-  angular.module('h').value('Bridge', Bridge)
+  angular.module('h').service 'bridge', Bridge
 else
   Annotator.Plugin.CrossFrame.Bridge = Bridge

h/static/scripts/cross-frame-service.coffee

@@ -4,12 +4,12 @@ class CrossFrameService
 
   this.inject = [
     '$rootScope', '$document', '$window', 'store', 'annotationUI'
-    'Discovery', 'Bridge',
+    'Discovery', 'bridge',
     'AnnotationSync', 'AnnotationUISync'
   ]
   constructor: (
     $rootScope, $document, $window, store, annotationUI
-    Discovery, Bridge,
+    Discovery, bridge,
     AnnotationSync, AnnotationUISync
   ) ->
     @providers = []
@@ -19,13 +19,6 @@ class CrossFrameService
         server: true
       new Discovery($window, options)
 
-    # Set up the bridge plugin, which bridges the main annotation methods
-    # between the host page and the panel widget.
-    createBridge = ->
-      options =
-        scope: 'annotator:bridge'
-      new Bridge(options)
-
     createAnnotationSync = (bridge) ->
       whitelist = ['target', 'document', 'uri']
       options =
@@ -63,7 +56,6 @@ class CrossFrameService
 
     this.connect = ->
       discovery = createDiscovery()
-      bridge = createBridge()
 
       bridge.onConnect(addProvider)
       annotationSync = createAnnotationSync(bridge)

h/static/scripts/guest.coffee

@@ -60,7 +60,6 @@ module.exports = class Annotator.Guest extends Annotator
     delete @options.app
 
     cfOptions =
-      scope: 'annotator:bridge'
       on: (event, handler) =>
         this.subscribe(event, handler)
       emit: (event, args...) =>

h/static/scripts/test/bridge-test.coffee

@@ -7,7 +7,7 @@ sinon.assert.expose assert, prefix: null
 
 describe 'Bridge', ->
   sandbox = sinon.sandbox.create()
-  createBridge = null
+  bridge = null
   createChannel = null
 
   before ->
@@ -15,9 +15,8 @@ describe 'Bridge', ->
     require('../bridge')
 
   beforeEach module('h')
-  beforeEach inject (Bridge) ->
-    createBridge = (options) ->
-      new Bridge(options)
+  beforeEach inject (_bridge_) ->
+    bridge = _bridge_
 
     createChannel = ->
       call: sandbox.stub()
@@ -34,21 +33,19 @@ describe 'Bridge', ->
   describe '.createChannel', ->
     it 'creates a new channel with the provided options', ->
       Channel.build.returns(createChannel())
-      bridge = createBridge()
       bridge.createChannel('WINDOW', 'ORIGIN', 'TOKEN')
 
       assert.called(Channel.build)
       assert.calledWith(Channel.build, {
         window: 'WINDOW'
         origin: 'ORIGIN'
-        scope: 'bridge:TOKEN'
+        scope: 'TOKEN'
         onReady: sinon.match.func
       })
 
     it 'adds the channel to the .links property', ->
       channel = createChannel()
       Channel.build.returns(channel)
-      bridge = createBridge()
       bridge.createChannel('WINDOW', 'ORIGIN', 'TOKEN')
 
       assert.include(bridge.links, {channel: channel, window: 'WINDOW'})
@@ -57,7 +54,6 @@ describe 'Bridge', ->
       channel = createChannel()
       Channel.build.returns(channel)
 
-      bridge = createBridge()
       bridge.on('message1', sinon.spy())
       bridge.on('message2', sinon.spy())
       bridge.createChannel('WINDOW', 'ORIGIN', 'TOKEN')
@@ -70,7 +66,6 @@ describe 'Bridge', ->
       channel = createChannel()
       Channel.build.returns(channel)
 
-      bridge = createBridge()
       ret = bridge.createChannel('WINDOW', 'ORIGIN', 'TOKEN')
 
       assert.equal(ret, channel)
@@ -80,7 +75,6 @@ describe 'Bridge', ->
       channel = createChannel()
       Channel.build.returns(channel)
 
-      bridge = createBridge()
       bridge.createChannel('WINDOW', 'ORIGIN', 'TOKEN')
       bridge.call({method: 'method1', params: 'params1'})
 
@@ -93,7 +87,6 @@ describe 'Bridge', ->
       channel = createChannel()
       Channel.build.returns(channel)
 
-      bridge = createBridge()
       bridge.createChannel('WINDOW', 'ORIGIN', 'TOKEN')
       bridge.call({method: 'method1', params: 'params1'})
 
@@ -108,7 +101,6 @@ describe 'Bridge', ->
 
       callback = sandbox.stub()
 
-      bridge = createBridge()
       Channel.build.returns(channel1)
       bridge.createChannel('WINDOW', 'ORIGIN', 'TOKEN')
       Channel.build.returns(channel2)
@@ -127,7 +119,6 @@ describe 'Bridge', ->
       channel2.call.yieldsTo('success', 'result2')
 
       callback = sandbox.stub()
-      bridge = createBridge()
 
       Channel.build.returns(channel1)
       bridge.createChannel('WINDOW', 'ORIGIN', 'TOKEN')
@@ -144,7 +135,6 @@ describe 'Bridge', ->
       channel.call.yieldsTo('error', new Error(''), 'A reason for the error')
       Channel.build.returns(channel)
 
-      bridge = createBridge()
       bridge.createChannel('WINDOW', 'ORIGIN', 'TOKEN')
       bridge.call({method: 'method1', params: 'params1', callback: sandbox.stub()})
 
@@ -155,7 +145,6 @@ describe 'Bridge', ->
       channel.call.yieldsTo('error', new Error(''), 'A reason for the error')
       Channel.build.returns(channel)
 
-      bridge = createBridge()
       bridge.createChannel('WINDOW', 'ORIGIN', 'TOKEN')
       bridge.call({method: 'method1', params: 'params1', callback: sandbox.stub()})
       bridge.call({method: 'method1', params: 'params1', callback: sandbox.stub()})
@@ -168,7 +157,6 @@ describe 'Bridge', ->
       Channel.build.returns(channel)
 
       callback = sandbox.stub()
-      bridge = createBridge()
       bridge.createChannel('WINDOW', 'ORIGIN', 'TOKEN')
       bridge.call({method: 'method1', params: 'params1', callback: callback})
 
@@ -180,7 +168,6 @@ describe 'Bridge', ->
       channel.call.yieldsTo('error', 'timeout_error', 'timeout')
       Channel.build.returns(channel)
 
-      bridge = createBridge()
       ret = bridge.call({method: 'method1', params: 'params1'})
       assert.isFunction(ret.then)
 
@@ -190,7 +177,6 @@ describe 'Bridge', ->
       message = {method: 'message1', params: 'params'}
       Channel.build.returns(channel)
 
-      bridge = createBridge()
       bridge.createChannel('WINDOW', 'ORIGIN', 'TOKEN')
       bridge.notify(message)
 
@@ -202,7 +188,6 @@ describe 'Bridge', ->
       channel = createChannel()
       Channel.build.returns(channel)
 
-      bridge = createBridge()
       bridge.createChannel('WINDOW', 'ORIGIN', 'TOKEN')
       bridge.on('message1', sandbox.spy())
 
@@ -210,7 +195,6 @@ describe 'Bridge', ->
       assert.calledWith(channel.bind, 'message1', sinon.match.func)
 
     it 'only allows one message to be registered per method', ->
-      bridge = createBridge()
       bridge.on('message1', sandbox.spy())
       assert.throws ->
         bridge.on('message1', sandbox.spy())
@@ -220,7 +204,6 @@ describe 'Bridge', ->
       channel = createChannel()
       Channel.build.returns(channel)
 
-      bridge = createBridge()
       bridge.createChannel('WINDOW', 'ORIGIN', 'TOKEN')
       bridge.off('message1', sandbox.spy())
 
@@ -229,7 +212,6 @@ describe 'Bridge', ->
       channel2 = createChannel()
       Channel.build.returns(channel1)
 
-      bridge = createBridge()
       bridge.createChannel('WINDOW', 'ORIGIN', 'TOKEN')
       bridge.off('message1', sandbox.spy())
 
@@ -243,7 +225,6 @@ describe 'Bridge', ->
       Channel.build.yieldsTo('onReady', channel)
 
       callback = sandbox.stub()
-      bridge = createBridge()
       bridge.onConnect(callback)
 
       bridge.createChannel('WINDOW', 'ORIGIN', 'TOKEN')
@@ -258,7 +239,6 @@ describe 'Bridge', ->
 
       callback1 = sandbox.stub()
       callback2 = sandbox.stub()
-      bridge = createBridge()
       bridge.onConnect(callback1)
       bridge.onConnect(callback2)
 

h/static/scripts/test/cross-frame-service-test.coffee

@@ -42,8 +42,7 @@ describe 'CrossFrameService', ->
     $provide.value('annotationUI', fakeAnnotationUI)
     $provide.value('Discovery',
       sandbox.stub().returns(fakeDiscovery))
-    $provide.value('Bridge',
-      sandbox.stub().returns(fakeBridge))
+    $provide.value('bridge', fakeBridge)
     $provide.value('AnnotationSync',
       sandbox.stub().returns(fakeAnnotationSync))
     $provide.value('AnnotationUISync',

h/static/scripts/test/guest-test.coffee

@@ -39,10 +39,6 @@ describe 'Annotator.Guest', ->
     sandbox.restore()
 
   describe 'setting up the bridge', ->
-    it 'sets the scope for the cross frame bridge', ->
-      guest = createGuest()
-      options = Annotator.Plugin.CrossFrame.lastCall.args[1]
-      assert.equal(options.scope, 'annotator:bridge')
 
     it 'provides an event bus for the annotation sync module', ->
       guest = createGuest()