What is the reason for injecting dependencies twice in AngularJS?

Question

What is the reason for injecting dependencies twice in AngularJS?

I'm a beginner in Angular and I'm curious to understand the reasoning behind injecting all our dependencies twice. Here is an example:

var analysisApp=angular.module('analysisApp',[]);

analysisApp.controller('analysisController',function($scope,$http,$cookies,$state,globalService){   

});

However, the code can also be written like this:

var analysisApp=angular.module('analysisApp',[]);

analysisApp.controller('analysisController',['$scope','$http','$cookies','$state','globalService',function($scope,$http,$cookies,$state,globalService){ 

}]);

But why do we need to do this?

javascript angularjs dependency-injection

Answer 1

Answer №1

To ensure the app is secure, it needs to be made minsafe.

Caution: When minifying your code, be aware that dependency names may be altered and could potentially disrupt the functionality of your app.

When you choose to minify all files, the dependencies will be replaced with generic terms like a, b, etc.

However, by using array and string syntax, as demonstrated in the following example, certain elements like string are not subject to minification and can be utilized for mapping purposes. This allows the app to recognize that a corresponds to $scope(View example below).

Example:

// Once minified
var _ = angular.module('analysisApp', []);

_.controller('analysisController', ['$scope', '$http', '$cookies', '$state', 'globalService', function (a, b, c, d, e) {
    a.name = 'John Doe'; // Now 'a' refers to `$scope`.
}]);

Refer to Angular Docs for more information.

Check out this helpful article on achieving minification safety with Grunt.

For best practices in minification, visit: Angularjs minify best practice

Answer 2

To ensure the app is secure, it needs to be made minsafe.

Caution: When minifying your code, be aware that dependency names may be altered and could potentially disrupt the functionality of your app.

When you choose to minify all files, the dependencies will be replaced with generic terms like a, b, etc.

However, by using array and string syntax, as demonstrated in the following example, certain elements like string are not subject to minification and can be utilized for mapping purposes. This allows the app to recognize that a corresponds to $scope(View example below).

Example:

// Once minified
var _ = angular.module('analysisApp', []);

_.controller('analysisController', ['$scope', '$http', '$cookies', '$state', 'globalService', function (a, b, c, d, e) {
    a.name = 'John Doe'; // Now 'a' refers to `$scope`.
}]);

Refer to Angular Docs for more information.

Check out this helpful article on achieving minification safety with Grunt.

For best practices in minification, visit: Angularjs minify best practice

Answer 3

Answer №2

Angular's implementation of dependency injection involves converting the function into a string and identifying its arguments. However, this method is problematic when minifying your code because variable names can become mangled, leading to malfunctions in your application. To address this issue, Angular allows you to specify the names of these injections using strings to prevent them from being mangled. In essence, after minification, your code might resemble the following:

analysisApp.controller('analysisController',
['$scope','$http','$cookies','$state','globalService', function(a,b,c,d,e) {

}]);

Internally, Angular will correspond $scope to a, $http to b, and so forth.

Alternatively, you can utilize ngannotate, a pre-processor tool that can be integrated into your build process. This tool transforms the initial code snippet into the annotated version mentioned above.

Answer 4

Angular's implementation of dependency injection involves converting the function into a string and identifying its arguments. However, this method is problematic when minifying your code because variable names can become mangled, leading to malfunctions in your application. To address this issue, Angular allows you to specify the names of these injections using strings to prevent them from being mangled. In essence, after minification, your code might resemble the following:

analysisApp.controller('analysisController',
['$scope','$http','$cookies','$state','globalService', function(a,b,c,d,e) {

}]);

Internally, Angular will correspond $scope to a, $http to b, and so forth.

Alternatively, you can utilize ngannotate, a pre-processor tool that can be integrated into your build process. This tool transforms the initial code snippet into the annotated version mentioned above.

Answer 5

Answer №3

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

app.controller('controller',['$scope','$http','$cookies','$state','service',function($scope,$http,$cookies,$state,service){ 

}]);

When minifying this code, it may look like:

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

app.controller('controller',['$scope','$http','$cookies','$state','service',function(a,b,c,d,e){ 

}]);

In this scenario, a, b, c, d will hold references to

'$scope','$http','$cookies','$state','service'

respectively and everything will function as expected.

The values of

'$scope','$http','$cookies','$state','service'

remain unchanged during minification since they are strings.

app.controller('controller',function($scope,$http,$cookies,$state,service){   

});

However, after minification, the above code may transform into:

app.controller('controller',function(a, b, c, d, e){   

});

At this point, Angular objects such as $scope lose their original meaning and the functionality breaks down.

Answer 6

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

app.controller('controller',['$scope','$http','$cookies','$state','service',function($scope,$http,$cookies,$state,service){ 

}]);

When minifying this code, it may look like:

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

app.controller('controller',['$scope','$http','$cookies','$state','service',function(a,b,c,d,e){ 

}]);

In this scenario, a, b, c, d will hold references to

'$scope','$http','$cookies','$state','service'

respectively and everything will function as expected.

The values of

'$scope','$http','$cookies','$state','service'

remain unchanged during minification since they are strings.

app.controller('controller',function($scope,$http,$cookies,$state,service){   

});

However, after minification, the above code may transform into:

app.controller('controller',function(a, b, c, d, e){   

});

At this point, Angular objects such as $scope lose their original meaning and the functionality breaks down.

What is the reason for injecting dependencies twice in AngularJS?

Answer №1

Answer №2

Answer №3

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