angular-vertxbus

Client side library using VertX Event Bus as an Angular Service module

Status

Branch	Stability	Status
Canary	unstable
Master	stable

How to get

Either download it manually or install it automatically with Bower: bower install angular-vertxbus --save

If you have a standard non AMD styled project, use dist/angular-vertxbus.js or dist/angular-vertxbus.min.js.

In case of an AMD styled project, there is also a package available at dist/requirejs/angular-vertxbus.js. In addition, because of the lack of vertxbus package, there is a Vert.X Event Bus package at dist/requirejs/vertxbus.js which includes the version of the Event Bus defined in the bower.json.

How to use

You have to define the module dependency, this module is named knalli.angular-vertxbus.

angular.module('your-component', ['knalli.angular-vertxbus']).controller('MyCtrl', function(vertxEventBus, vertxEventBusService){

  // using the EventBus directly
  vertxEventBus.send('my.address', {data: 123});

  // using the service
  vertxEventBusService.send('my.address', {data: 123})

});

Consume messages

vertxEventBusService.on('myaddress', function(message) {
  console.log('Received a message: ', message);
});

Publish a message

vertxEventBusService.publish('myaddress', {data: 123});

Send a message

vertxEventBusService.send('myaddress', {data: 123}).then(function(reply){
  console.log('A reply received: ', reply);
}).catch(function(){
  console.warn('No message');
});

// The "No reply message found" is controlled via a timeout (default 10000ms)
vertxEventBusService.send('myaddress', {data: 123}, 3000).then(function(reply){
  console.log('A reply received: ', reply);
}).catch(function(){
  console.warn('No message within 3 seconds');
});

Advanced configuration

The module has some advanced configuration options. Perhaps you do not have to change them, but at least you should know them!

Each module configuration option must be defined in the run phase, i.e.:

var module = angular.module('your-component', ['knalli.angular-vertxbus']);
module.config(function(vertxEventBusProvider) {
  vertxEventBusProvider
  .enable()
  .useReconnect()
  .useUrlServer('http://live.example.org:8888');
});

Config Function	Default	Description
enable(bool)	true	if false, the usage of the Event Bus will be disabled (actually, no vertx.EventBus will be created)
useDebug(bool)	false	if true, some additional debug loggings will be displayed
usePrefix(string)	'vertx-eventbus.'	a prefix used for the global broadcasts
useUrlServer(string)	(same origin)*	full URL to the server (must be changed if the target server is not the origin)
useUrlPath(string)	'/eventbus'	path to the event bus
useReconnect	true	if false, the disconnect will be recognized but no further actions
useSockJsStateInterval	10000 (ms)	defines the check interval of the underlayling SockJS connection
useSockJsReconnectInterval	10000 (ms)	defines the wait time for a reconnect after a disconnect has been recognized
useSockJsOptions	{}	optional SockJS options (technically new SockJS(url, undefined, sockjsOptions))

• location.protocol + '//' + location.hostname + ':' + (location.port or 80)

Architecture details

The module contains two items: the stub holder vertxEventBus for the Vert.X EventBus and a more comfortbale high level service vertxEventBusService.

The stub is required because the Vert.X Event Bus cannot handle a reconnect. The reason is the underlaying SockJS which cannot handle a reconnect, too. A reconnect means to create a new instance of SockJS, therefore a new instanve of vertx.EventBus. The stub ensures only one single instance exists. Otherwise a global module was not possible.

More or less the stub supports the same API calls like the original vertx.EventBus.

Based on the stub, the high level service vertxEventBusService detects disconnects, handles reconnects and ensures re-registrations of subscriptions. Furthermore, the service provides some neat aliases for the usage of handlers.

// Same as vertx.EventBus.registerHandler()
service.registerHandler('myaddress', callback);
service.on('myaddress', callback);
service.addListener('myaddress', callback);

// Same as vertx.EventBus.unregisterHandler()
service.unregisterHandler('myaddress', callback);
service.un('myaddress', callback);
service.removeListener('myaddress', callback);

// Same as vertx.EventBus.send()
service.send('myaddress', data)

// Same as vertx.EventBus.publish
service.publish('myaddress', data)
service.emit('myaddress', data)

// Same as vertx.readyState()
service.readyState()

In addition to this, when sending a message with an expected reply:

// Same as vertx.EventBus.send() but with a promise
service.send('myaddress', data).then(function(replyMessage) {})

For each connect or disconnect, a global broadcast will be emitted (on $rootScope with 'vertx-eventbus.system.connected', 'vertx-eventbus.system.disconnected')

Setup for using same callback with different addresses

In some scenarios you will want to use a single callback definition to many different addresses. To do this you will have to follow this pattern.

Create a javascript object that defines your callback. Do not attempt to use .prototype as the methods defined as such will always point to the same memory allocation - so will always be found identical when adding to the internal array.

function FunctionHolder(){
  "use strict";
  return {
      handler: function (message) {
          // do stuff here
      }
  }
};

Then when adding the listeners, you will create a new instance of your object and use your defined function.

var funcHolder = new FunctionHolder();
vertxEventBusService.addListener('address', funcHolder.handler);

NOTE: this functionality is only available after version 0.8.0.

Tests

Unit tests

Note: Check that dependencies are be installed (npm install).

The unit tests are available with npm test which is actually a shortcut for grunt test. It performs tests under the current primary target version of AngularJS. Use npm run-script test-scopes for testing other scoped versions as well.

E2E tests (manually)

Note: Check that dependencies are be installed (npm install).

The end-to-end tests start and utilize a full Vert.X node and a NodeJS based web server.

1. npm run-script install-it-vertx-server downloads and installs a Vert.X locally.
2. npm run-script start-it-vertx-server starts Vert.X on port 8080.
3. npm run-script start-it-web-server starts a web server on port 3000.
4. Open http://localhost:3000/ in your browser.

License

Copyright 2014 by Jan Philipp. Licensed under MIT.