AngularJS seed: putting JavaScript into separate files (app.js, controllers.js, directives.js, filters.js, services.js)

Question

I'm using the angular-seed template to structure my application. Initially I put all my JavaScript code into a single file, main.js. This file contained my module declaration, controllers, directives, filters, and services. The application works fine like this, but I'm worried about scalability and maintainability as my application becomes more complex. I noticed that the angular-seed template has separate files for each of these, so I've attempted to distribute my code from the single main.js file into each of the other files mentioned in the title to this question and found in the app/js directory of the angular-seed template.

My question is: how do I manage the dependencies to get the application to work? The existing documentation found here isn't very clear in this regard since each of the examples given shows a single JavaScript source file.

An example of what I have is:

app.js

angular.module('myApp', 
    ['myApp.filters',
     'myApp.services',
     'myApp.controllers']);

controllers.js

angular.module('myApp.controllers', []).
    controller('AppCtrl', [function ($scope, $http, $filter, MyService) {

        $scope.myService = MyService; // found in services.js

        // other functions...
    }
]);

filters.js

angular.module('myApp.filters', []).
    filter('myFilter', [function (MyService) {
        return function(value) {
            if (MyService.data) { // test to ensure service is loaded
                for (var i = 0; i < MyService.data.length; i++) {
                    // code to return appropriate value from MyService
                }
            }
        }
    }]
);

services.js

angular.module('myApp.services', []).
    factory('MyService', function($http) {
        var MyService = {};
        $http.get('resources/data.json').success(function(response) {
            MyService.data = response;
        });
        return MyService;
    }
);

main.js

/* This is the single file I want to separate into the others */
var myApp = angular.module('myApp'), []);

myApp.factory('MyService', function($http) {
    // same code as in services.js
}

myApp.filter('myFilter', function(MyService) {
    // same code as in filters.js
}

function AppCtrl ($scope, $http, $filter, MyService) {
    // same code as in app.js
}

How do I manage the dependencies?

Thanks in advance.

Answer 1

The problem is caused from you "redeclaring" your application module in all your separate files.

This is what the app module declaration (not sure declaration is the right term) looks like:

angular.module('myApp', []).controller( //...

This is what assignment (not sure if assignment is the right term either) to your application module looks like:

angular.module('myApp').controller( //...

Notice the lack of square brackets.

So, the former version, one with the square brackets, should only be used once, usually in your app.js or main.js. All other associated files — controllers, directives, filters … — should use the latter version, the one without the square brackets.

I hope that makes sense. Cheers!