How to access the services from RESTful API in my angularjs page?

Question

I am very new to angularJS. I am searching for accessing services from RESTful API, but I didn't get any idea. How can I do that?

Dimmer

Answer 1

Option 1: $http service

AngularJS provides the $http service that does exactly what you want: Sending AJAX requests to web services and receiving data from them, using JSON (which is perfectly for talking to REST services).

To give an example (taken from the AngularJS documentation and slightly adapted):

$http({ method: 'GET', url: '/foo' }).
  success(function (data, status, headers, config) {
    // ...
  }).
  error(function (data, status, headers, config) {
    // ...
  });

Option 2: $resource service

Please note that there is also another service in AngularJS, the $resource service which provides access to REST services in a more high-level fashion (example again taken from AngularJS documentation):

var Users = $resource('/user/:userId', { userId: '@id' });
var user = Users.get({ userId: 123 }, function () {
  user.abc = true;
  user.$save();
});

Option 3: Restangular

Moreover, there are also third-party solutions, such as Restangular. See its documentation on how to use it. Basically, it's way more declarative and abstracts more of the details away from you.

Muricate

Can you please help me here. I am getting no idea. #16463956. I am unable to load the service from REST API. getting an empty array. Thank You – Dimmer

@GoloRoden i saw someone using $http.defaults.useXDomain = true in angular when dealing with CORS. Is it really necessary to do that? because I just set up laravel and angular in different domain. i hit the laravel controller with http request from angular. It just work fine, Whether i use the $http.defaults.useXDomain or not. Is there any logical explanation for this? – Don

Answer 2

The $http service can be used for general purpose AJAX. If you have a proper RESTful API, you should take a look at ngResource.

You might also take a look at Restangular, which is a third party library to handle REST APIs easy.

Pyxis

Answer 3

Welcome to the wonderful world of Angular !!

I am very new to angularJS. I am searching for accessing services from RESTful API but I didn't get any idea. please help me to do that. Thank you

There are two (very big) hurdles to writing your first Angular scripts, if you're currently using 'GET' services.

First, your services must implement the "Access-Control-Allow-Origin" property, otherwise the services will work a treat when called from, say, a web browser, but fail miserably when called from Angular.

So, you'll need to add a few lines to your web.config file:

<configuration>
  ... 
  <system.webServer>
    <httpErrors errorMode="Detailed"/>
    <validation validateIntegratedModeConfiguration="false"/>
    <!-- We need the following 6 lines, to let AngularJS call our REST web services -->
    <httpProtocol>
        <customHeaders>
            <add name="Access-Control-Allow-Origin" value="*"/>
            <add name="Access-Control-Allow-Headers" value="Content-Type"/>
        </customHeaders>
    </httpProtocol>
  </system.webServer>
  ... 
</configuration>

Next, you need to add a little bit of code to your HTML file, to force Angular to call 'GET' web services:

// Make sure AngularJS calls our WCF Service as a "GET", rather than as an "OPTION"
var myApp = angular.module('myApp', []);
myApp.config(['$httpProvider', function ($httpProvider) {
    $httpProvider.defaults.useXDomain = true;
    delete $httpProvider.defaults.headers.common['X-Requested-With'];
}]);

Once you have these fixes in place, actually calling a RESTful API is really straightforward.

function YourAngularController($scope, $http) 
{
    $http.get('http://www.iNorthwind.com/Service1.svc/getAllCustomers')
        .success(function (data) {
        //  
        //  Do something with the data !
        //  
    });
}

You can find a really clear walkthrough of these steps on this webpage:

Using Angular, with JSON data

Good luck !

Mike

Layard

Why would you encourage someone to totally open their web services to the internet? The Access-Control-Allow-Origin should never be a wild-card unless you're a public facing API... – Talos

Answer 4

Just to expand on $http (shortcut methods) here: http://docs.angularjs.org/api/ng.$http

//Snippet from the page

$http.get('/someUrl').success(successCallback);
$http.post('/someUrl', data).success(successCallback);

//available shortcut methods

$http.get
$http.head
$http.post
$http.put
$http.delete
$http.jsonp

Jukebox

.success() and .error() is deprected. you should use .then() and .catch() instead – Conjunct

Answer 5

For instance your json looks like this : {"id":1,"content":"Hello, World!"}

You can access this thru angularjs like so:

angular.module('app', [])
    .controller('myApp', function($scope, $http) {
        $http.get('http://yourapp/api').
            then(function(response) {
                $scope.datafromapi = response.data;
            });
    });

Then on your html you would do it like this:

<!doctype html>
<html ng-app="myApp">
    <head>
        <title>Hello AngularJS</title>
        <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.4.3/angular.min.js"></script>
        <script src="hello.js"></script>
    </head>

    <body>
        <div ng-controller="myApp">
            <p>The ID is {{datafromapi.id}}</p>
            <p>The content is {{datafromapi.content}}</p>
        </div>
    </body>
</html>

This calls the CDN for angularjs in case you don't want to download them.

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.4.3/angular.min.js"></script>
<script src="hello.js"></script>

Hope this helps.

Colonic