Differences between Angular's $injector and Angular's dependency injectionAngular

Question

Differences between Angular's $injector and Angular's dependency injectionAngular

As a newcomer to Angular, I am exploring the use of $injector and its get function to retrieve specific services. For instance:

app.factory('$myService', function($injector) {
   return { ...
            var http = $injector.get('$http');
            ....
   }
}

This code snippet shows how to assign the Angular $http service to the variable http.

In some other examples, I have encountered syntax like this:

app.factory('$myService', function($http) {
    return {...}

Here, the $http service is injected directly into the factory.

Are there any differences between these two approaches? When would be the appropriate time to use one over the other?

Thanks in advance!

javascript angularjs

Answer 1

Answer №1

Do you think it's the same or do you have a preference?

In my view, directly injecting your dependencies (such as $http) is more beneficial for readability.

Keep in mind that you also have the option to utilize the $inject annotation:

someModule.controller('MyController', MyController);
MyController.$inject = ['$http'];

var MyController = function($http) {
    // ...
}

Answer 2

Do you think it's the same or do you have a preference?

In my view, directly injecting your dependencies (such as $http) is more beneficial for readability.

Keep in mind that you also have the option to utilize the $inject annotation:

someModule.controller('MyController', MyController);
MyController.$inject = ['$http'];

var MyController = function($http) {
    // ...
}

Answer 3

Answer №2

Although they serve similar purposes, the way in which you utilize them varies. When working with a controller where the requirements are known in advance, it is generally preferable to use parameter-based injection:

var controller = ['$http', function($http){ /* Controller stuff here */ }];

However, in more complex scenarios where all dependencies may not be known (such as creating a sub-framework that allows users to specify dependencies), it may be necessary to programmatically inject dependencies using $injector:

var controller = ['$scope','$injector', function($scope, $injector){
    $scope.dependencies = [];
    $scope.injectFromString = function(dependency){
        $scope.dependencies.push($injector.get(dependency));
    };
}];`

Answer 4

Although they serve similar purposes, the way in which you utilize them varies. When working with a controller where the requirements are known in advance, it is generally preferable to use parameter-based injection:

var controller = ['$http', function($http){ /* Controller stuff here */ }];

However, in more complex scenarios where all dependencies may not be known (such as creating a sub-framework that allows users to specify dependencies), it may be necessary to programmatically inject dependencies using $injector:

var controller = ['$scope','$injector', function($scope, $injector){
    $scope.dependencies = [];
    $scope.injectFromString = function(dependency){
        $scope.dependencies.push($injector.get(dependency));
    };
}];`

Differences between Angular's $injector and Angular's dependency injectionAngular

Answer №1

Answer №2

Similar questions

Display visual information without requiring the parameters to be filtered beforehand in vue.js

What is the best way to send props to a styled component without needing to convert them to transient props beforehand

When data is stored in Internet Explorer's cache, any changes made are not being reflected in

Tips for extracting the two characters following a space in a string with or without the use of regex

Can Node.js be utilized to generate an XLS excel file while specifying the cell type?

Retrieve JSON data from PHP using D3.request

Resolve the route expression before the API request is fully processed

Tips on boosting the speed and user-friendliness of your AJAX/REST application

Delay the occurrence of a hover effect until the previous effect has finished executing

Providing input to a nested mongoose query

Does React have an event component that detects when a user is actively viewing a specific component, such as a post?

Tips for showcasing elements individually in JavaScript when a button is clicked and halting on a random element

Ways to eliminate all attributes and their corresponding values within HTML tags

What is the best method for converting IDs into objects within ng-options in Angular?

Incorporating the non-typescript npm package "pondjs" into Meteor applications using typescript files

Passing arguments to EJS view with Express

"The error message appeared stating that the AngularJS Protractor element cannot be clicked at its current position due to another element

What is the best way to create a Div element that functions as a button, becoming active when clicked while deactivating all other Div elements

Highchart displays text centrally on legend hover

Selectize Fails to Populate Options Using Ajax