Writing Browserify modules for your Angular app

How to create little re-usable modules

Following up on my previous Let’s Build an angular app with Browserify post I got a few questions on how to create modules for your app. Let me show you.

If you haven’t already, make sure you’ve read the walkthrough on how to set up the environment to work with Browserify and Gulp, so you can follow along.

Basically, what you do when you require() a module, is looking for what the script you require exposes to the outside world through module.exports. This is following the CommonJS spec. This allows us to encapsulate functionality privately within our module, and only export the ‘public’ methods or variables to the outside world.

Now, what does this look like for our Browserify Angular app?

A Controller module

Let’s assume we’re using ui-router for the awesome stateprovider, and want to specify one of our own controllers through require()

var app = angular.module('myApp', ['uiRouter']);

$stateProvider

  .state('about', {
    views: {
      'contents': {
        controller: require('./controllers/AboutCtrl').inject(app),
        templateUrl: '/views/home.html'
      }
    }
  });

What we do here is not that much different from the plain old way, but instead of including a script tag to controllers/AboutCtrl.js and using the name, we call require() on our module, and call .injdect(app) on it.

This works, because our module exports an angular controller object, which it is able to do because we inject our app. Here’s what it looks like:

exports.inject = function(app) {
  app.controller('AboutCtrl', exports.controller);
  return exports.controller;
};

exports.controller = function AboutCtrl($scope) {
  $scope.regularAngular = 'Hello!';
};

As you can see, our inject function takes the app, and in turn returns our controller function. Simple, clean and effective.

Dependency injection

But what if we want to use a dependency. Simply require it and inject it:

exports.inject = function(app) {
  require('./../services/SomeService').inject(app); // Require the someservice module
  app.controller('AboutCtrl', exports.controller);
  return exports.controller;
};

// Pass the SomeService as parameter
exports.controller = function AboutCtrl($scope, SomeService) {
  // And profit.
  $scope.regularAngular = SomeService.getYourStuff();
};

This is how that SomeService would look like. Not much different, but instead of exposing a controller, we return a factory:

exports.inject = function(app) {
  app.factory('SomeService', exports.factory);
  return exports.factory;
};

// Any extra dependencies can just be passed in
exports.factory = function($http, $cookieStore, $resource) {

  var monkey = 'Strawberry';

  return {
    getYourStuff: function() {
      return monkey;
    }
  }
};

And that’s how we can write little re-usable modules to use in our Angular App!

I hope the above helps, and if you have any questions feel free to ask.

Happy coding.


Questions or comments?

As always, if you have any questions or comments, you can find me on Twitter.