AngularJS API

AngularJS API refers to the set of core functions and objects available in AngularJS to help developers interact with the framework, manage dependencies, manipulate data, and control the application's behavior. These APIs are the foundation for building AngularJS applications and provide essential utilities for various tasks like HTTP requests, routing, and more.

Key Components of the AngularJS API

1. Module API

• The angular.module API is used to define and configure AngularJS modules, which act as containers for components like controllers, services, and directives.
• You can create an AngularJS module and attach components to it.

Example:

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

2. Controller API

• The angular.controller API allows you to define controllers that manage the behavior and data for a view (HTML page).
• Controllers contain the logic for the application and are attached to a scope object to provide data binding.

Example:

app.controller('myCtrl', function($scope) {
    $scope.message = 'Hello, AngularJS!';
});

3. Service API

• Services in AngularJS are singleton objects that can be injected into other parts of the application.
• Services are used to share logic, data, and functionality across multiple controllers or directives.

Example:

app.service('myService', function() {
    this.getData = function() {
        return 'Data from service';
    };
});

4. Factory API

• A factory is a function that returns an object. Factories provide a way to create more flexible and dynamic services or objects.
• Factories are commonly used for complex services or when the service needs to return different objects or data depending on specific conditions.

Example:

app.factory('myFactory', function() {
    return {
        getMessage: function() {
            return 'Hello from Factory!';
        }
    };
});

5. Directive API

• The angular.directive API allows you to create custom HTML elements, attributes, or classes that can be used to add functionality to the application views.
• Directives can be used for various purposes such as DOM manipulation or event handling.

Example:

app.directive('myDirective', function() {
    return {
        template: '<h1>Hello from Directive!</h1>'
    };
});

6. Filter API

• AngularJS filters are used to format data for display in the view. They can be applied to expressions and bindings in templates.
• Filters are often used to format dates, currency, or perform sorting and searching on collections.

Example:

app.filter('capitalize', function() {
    return function(input) {
        return input.charAt(0).toUpperCase() + input.slice(1);
    };
});

7. $http API

• The $http service in AngularJS is used to make HTTP requests to retrieve or send data to external servers or APIs.
• It supports various HTTP methods like GET, POST, PUT, DELETE, etc.

Example:

app.controller('myCtrl', function($scope, $http) {
    $http.get('https://api.example.com/data')
        .then(function(response) {
            $scope.data = response.data;
        });
});

8. $routeProvider API

• The $routeProvider API is used to configure routing in AngularJS applications. Routing helps in navigating between different views and maintaining a single-page application (SPA) architecture.

Example:

app.config(function($routeProvider) {
    $routeProvider
        .when('/home', {
            templateUrl: 'home.html',
            controller: 'homeCtrl'
        })
        .when('/about', {
            templateUrl: 'about.html',
            controller: 'aboutCtrl'
        });
});

9. $scope API

• The $scope object is the glue between the controller and the view. It holds the data and functions that are available to the view.
• $scope is used to bind the data between the controller and the view in the AngularJS application.

Example:

app.controller('myCtrl', function($scope) {
    $scope.greeting = 'Hello, AngularJS!';
});

10. $compile API

• The $compile API is used to compile and link HTML elements to AngularJS scopes. It is generally used to dynamically add or manipulate elements in the DOM.
• $compile allows the injection of AngularJS directives and expressions into dynamically created HTML.

Example:

app.controller('myCtrl', function($scope, $compile) {
    var dynamicHTML = '<div>{{ greeting }}</div>';
    var compiled = $compile(dynamicHTML)($scope);
    angular.element(document.body).append(compiled);
});

11. $location API

• The $location service is used to interact with the browser's URL and the browser's history state. It helps in managing the application's routing without the need to reload the page.
• $location is used to get or set the URL, manipulate query parameters, and manage the history state.

Example:

app.controller('myCtrl', function($scope, $location) {
    $scope.goToPage = function() {
        $location.path('/newPage');
    };
});

12. $timeout API

• The $timeout service in AngularJS is similar to JavaScript's setTimeout, but it is integrated with AngularJS's digest cycle, which means it will work with AngularJS's two-way data binding and update the view automatically.
• It allows you to execute functions after a specified delay.

Example:

app.controller('myCtrl', function($scope, $timeout) {
    $timeout(function() {
        $scope.message = 'This message is delayed!';
    }, 2000);
});

 

Summary

The AngularJS API provides a rich set of services and tools for building dynamic, interactive web applications. It includes modules for managing components like controllers, directives, filters, and services. With built-in support for HTTP requests, routing, and DOM manipulation, AngularJS makes it easier to develop sophisticated single-page applications (SPAs). Additionally, services like $scope, $http, and $timeout simplify common tasks such as data binding, API interaction, and asynchronous behavior. Understanding the AngularJS API is crucial for developers to efficiently build scalable and maintainable applications.