Refactor controller functions as services declared in different files
As you correctly stated, a great approach to refactor the functions is to put them into different services.
According to the angular Service docs:
Angular services are singletons objects or functions that carry out specific tasks common to web apps.
Here is an example:
Original code
Here we have a simple Hello World app, with a controller that has two functions: greet() and getName().
app.js
var app = angular.module('plunker', []);
app.controller('MainCtrl', function($scope) {
$scope.getName = function () {
return 'World';
}
$scope.greet = function (name) {
return 'Hello ' + name;
};
});
index.html
...
<div id="container" ng-controller="MainCtrl">
<h1>{{greet(getName())}}</h1>
</div>
...
We want to test that our scope always has both functions, so we know it is working as intended, so we are going to write two simple jasmine tests:
appSpec.js
describe('Testing a Hello World controller', function() {
var $scope = null;
var ctrl = null;
//you need to indicate your module in a test
beforeEach(module('plunker'));
beforeEach(inject(function($rootScope, $controller) {
$scope = $rootScope.$new();
ctrl = $controller('MainCtrl', {
$scope: $scope
});
}));
it('should say hallo to the World', function() {
expect($scope.getName()).toEqual('World');
});
it('shuld greet the correct person', function () {
expect($scope.greet('Jon Snow')).toEqual('Hello Jon Snow');
})
});
Check it out in plnkr
Step 1: Refactor controller functions into separate functions
In order to start decoupling our controller to our functions we are going to make two individual functions inside app.js.
app.js
var app = angular.module('plunker', []);
app.controller('MainCtrl', function($scope) {
$scope.getName = getName;
$scope.greet = greet;
});
function getName() {
return 'World';
}
function greet(name) {
return 'Hello ' + name;
}
Now we check our test output and we see that everything is working perfectly.
Check out the plnkr for step 1
Step 2: Move functions to their own services
We will define a NameService and GreetService, put our functions in them and then define the services as dependencies in our controller.
app.js
var app = angular.module('plunker', []);
app.service('NameService', function () {
this.getName = function getName() {
return 'World';
};
});
app.service('GreetService', function() {
this.greet = function greet(name) {
return 'Hello ' + name;
}
});
app.controller('MainCtrl', ['$scope', 'NameService', 'GreetService', function($scope, NameService, GreetService) {
$scope.getName = NameService.getName;
$scope.greet = GreetService.greet;
}]);
We make sure that our tests are still green, so we can move on to the final step.
Have a look at step 2 in plunker
Final Step: Put our services in different files
Finally we will make two files, NameService.js and GreetService.js and put our services in them.
NameService.js
angular.module('plunker').service('NameService', function () {
this.getName = function getName() {
return 'World';
};
});
GreetService.js
angular.module('plunker').service('GreetService', function() {
this.greet = function greet(name) {
return 'Hello ' + name;
}
});
We also need to make sure to add the new scripts to our index.html
index.html
...
<script src="NameService.js"></script>
<script src="GreetService.js"></script>
...
This is how our controller looks like now, neat huh?
app.js
var app = angular.module('plunker', []);
app.controller('MainCtrl', ['$scope', 'NameService', 'GreetService', function($scope, NameService, GreetService) {
$scope.getName = NameService.getName;
$scope.greet = GreetService.greet;
}]);
Plunker for the final step.
And that's it! Our tests still pass, so we know everything works like a charm.
