ember-ajax

Service for making AJAX requests in Ember 1.13+ applications.

• customizable service
• returns RSVP promises
• improved error handling
• ability to specify request headers
• upgrade path from ic-ajax

Getting started

To use the ajax service, inject the ajax service into your route or component.

import Ember from 'ember';

export default Ember.Route.extend({
  ajax: Ember.inject.service(),
  model() {
    return this.get('ajax').request('/posts');
  }
});

Ajax Service

Basic Usage

The AJAX service provides methods to be used to make AJAX requests, similar to the way that you would use jQuery.ajax. In fact, ember-ajax is a wrapper around jQuery's method, and can be configured in much the same way.

In general, you will use the request(url, options) method, where url is the destination of the request and options is a configuration hash for jQuery.ajax.

import Ember from 'ember';

export default Ember.Controller.extend({
  ajax: Ember.inject.service(),
  actions: {
    sendRequest() {
      return this.get('ajax').request('/posts', {
        method: 'POST',
        data: {
          foo: 'bar'
        }
      });
    }
  }
});

In this example, this.get('ajax').request() will return a promise with the result of the request. Your handler code inside .then or .catch will automatically be wrapped in an Ember run loop for maximum compatibility with Ember, right out of the box.

HTTP-verbed methods

You can skip setting the method or type keys in your options object when calling request(url, options) by instead calling post(url, options), put(url, options), patch(url, options) or del(url, options).

post('/posts', { data: { title: 'Ember' } })    // Makes a POST request to /posts
put('/posts/1', { data: { title: 'Ember' } })   // Makes a PUT request to /posts/1
patch('/posts/1', { data: { title: 'Ember' } }) // Makes a PATCH request to /posts/1
del('/posts/1')                                 // Makes a DELETE request to /posts/1

Custom Request Headers

ember-ajax allows you to specify headers to be used with a request. This is especially helpful when you have a session service that provides an auth token that you have to include with the requests to authorize your requests.

To include custom headers to be used with your requests, you can specify headers hash on the Ajax Service.

// app/services/ajax.js

import Ember from 'ember';
import AjaxService from 'ember-ajax/services/ajax';

export default AjaxService.extend({
  session: Ember.inject.service(),
  headers: Ember.computed('session.authToken', {
    get() {
      let headers = {};
      const authToken = this.get('session.authToken');
      if (authToken) {
        headers['auth-token'] = authToken;
      }
      return headers;
    }
  })
});

Headers by default are only passed if the hosts match, or the request is a relative path. You can overwrite this behavior by either passing a host in with the request, setting the host for the ajax service, or by setting an array of trustedHosts that can be either an array of strings or regexes.

// app/services/ajax.js

import Ember from 'ember';
import AjaxService from 'ember-ajax/services/ajax';

export default AjaxService.extend({
  trustedHosts: [
    /\.example\./,
    'foo.bar.com',
  ]
});

Custom Endpoint Path

The namespace property can be used to prefix requests with a specific url namespace.

// app/services/ajax.js

import Ember from 'ember';
import AjaxService from 'ember-ajax/services/ajax';

export default AjaxService.extend({
  namespace: '/api/v1'
});

request('/users/me') would now target /api/v1/users/me

If you need to override the namespace for a custom request, use the namespace as an option to the request methods.

// GET /api/legacy/users/me
request('/users/me', { namespace: '/api/legacy' })

Custom Host

ember-ajax allows you to specify a host to be used with a request. This is especially helpful so you don't have to continually pass in the host along with the path, makes request() a bit cleaner.

To include a custom host to be used with your requests, you can specify host property on the Ajax Service.

// app/services/ajax.js

import Ember from 'ember';
import AjaxService from 'ember-ajax/services/ajax';

export default AjaxService.extend({
  host: 'http://api.example.com'
});

That allows you to only have to make a call to request() as such:

// GET http://api.example.com/users/me
request('/users/me')

You can even leave off the forward slash if you'd like:

// GET http://api.example.com/users/me
request('users/me')

Custom Content-Type

ember-ajax allows you to specify a default Content-Type header to be used with a request.

To include a custom Content-Type you can specify contentType property on the Ajax Service.

// app/services/ajax.js

import Ember from 'ember';
import AjaxService from 'ember-ajax/services/ajax';

export default AjaxService.extend({
  contentType: 'application/json; charset=utf-8'
});

You can also override the Content-Type per request with the options parameter.

Customize isSuccess

Some APIs respond with status code 200, even though an error has occurred and provide a status code in the payload. With the service, you can easily account for this behaviour by overwriting the isSuccess method.

// app/services/ajax.js

import AjaxService from 'ember-ajax/services/ajax';

export default AjaxService.extend({
  isSuccess(status, headers, payload ) {
    let isSuccess = this._super(...arguments);
    if (isSuccess && payload.status) {
      // when status === 200 and payload has status property,
      // check that payload.status is also considered a success request
      return this._super(payload.status);
    }
    return isSuccess;
  }
});

Error handling

ember-ajax provides built in error classes that you can use to check the error that was returned by the response. This allows you to restrict determination of error result to the service instead of sprinkling it around your code.

Built in error types

ember-ajax has built-in error types that will be returned from the service in the event of an error:

• BadRequestError (400)
• UnauthorizedError(401)
• ForbiddenError(403)
• NotFoundError (404)
• InvalidError(422)
• ServerError (5XX)
• AbortError
• TimeoutError

All of the above errors are subtypes of AjaxError.

Error detection helpers

ember-ajax comes with helper functions for matching response errors to their respective ember-ajax error type. Each of the errors listed above has a corresponding is* function (e.g., isBadRequestError).

Use of these functions is strongly encouraged to help eliminate the need for boilerplate error detection code.

import Ember from 'ember';
import {isAjaxError, isNotFoundError, isForbiddenError} from 'ember-ajax/errors';

export default Ember.Route.extend({
  ajax: Ember.inject.service(),
  model() {
    const ajax = this.get('ajax');

    return ajax.request('/user/doesnotexist')
      .catch(function(error) {
        if (isNotFoundError(error)) {
          // handle 404 errors here
          return;
        }

        if (isForbiddenError(error)) {
          // handle 403 errors here
          return;
        }

        if(isAjaxError(error)) {
          // handle all other AjaxErrors here
          return;
        }

        // other errors are handled elsewhere
        throw error;
      });
  }
});

If your errors aren't standard, the helper function for that error type can be used as the base to build your custom detection function.

Access the response in case of error

If you need to access the json response of a request that failed, you can use the raw method instead of request.

this.get('ajax').raw(url, options)
  .then(({ response }) => this.handleSuccess(response))
  .catch(({ response, jqXHR, payload }) => this.handleError(response));

Note that in this use case there's no access to the error object. You can inspect the jqXHR object for additional information about the failed request. In particular jqXHR.status returns the relevant HTTP error code.

Usage with Ember Data

Ember AJAX provides a mixin that can be used in an Ember Data Adapter to avoid the networking code provided by Ember Data and rely on Ember AJAX instead. This serves as a first step toward true integration of Ember AJAX into Ember Data.

To use the mixin, you can include the mixin into an Adapter, like so:

// app/adapters/application.js
import DS from 'ember-data';
import AjaxServiceSupport from 'ember-ajax/mixins/ajax-support';

export default DS.JSONAPIAdapter.extend(AjaxServiceSupport);

That's all the configuration required! If you want to customize the adapter, such as using an alternative AJAX service (like one you extended yourself), hooks to do so are provided; check out the mixin's implementation for details.

Note that instead of using the Ember Data error checking code in your application, you should use the ones provided by Ember AJAX.

Stand-Alone Usage

If you aren't using Ember Data and do not have access to services, you can import the ajax utility like so:

import request from 'ember-ajax/request';

export default function someUtility(url) {
  var options = {
    // request options
  };

  return request(url, options).then(response => {
    // `response` is the data from the server
    return response;
  });
}

Which will have the same API as the ajax service. If you want the raw jQuery XHR object then you can use the raw method instead:

import raw from 'ember-ajax/raw';

export default function someOtherUtility(url) {
  var options = {
    // raw options
  };

  return raw(url, options).then(result => {
    // `result` is an object containing `response` and `jqXHR`, among other items
    return result;
  });
}

Testing

Fixture Data

When writing tests, you will often need to provide fixture data for your application. This can be accomplished by mocking your server with Pretender.js. You can use it directly with ember-cli-pretender or through a helper library.

If you're looking for a full featured mock server with fixtures support, choose EmberCLI Mirage otherwise use the leaner EmberCLI Fake Server.

Error Handling

When writing integration & acceptance tests, your tests should be testing for what the user can see. Therefore, your tests should be checking if the errors are in the DOM. If errors bubble up to the console, then you should catch the failure in your app code and present the errors to the user.

Acceptance Tests

import { test } from 'qunit';
import moduleForAcceptance from 'dummy/tests/helpers/module-for-acceptance';

import Pretender from 'pretender';

let server;

moduleForAcceptance('ajax-get component', {
  beforeEach() {
    server = new Pretender();
  },
  afterEach() {
    server.shutdown();
  }
});

test('waiting for a route with async widget', function(assert) {

  const PAYLOAD = [{ title: 'Foo' }, { title: 'Bar' }, { title: 'Baz' }];

  server.get('/posts', function(){
    return [ 200, {"Content-Type": "application/json"}, JSON.stringify(PAYLOAD) ];
  }, 300);

  visit('/');

  andThen(function() {
    assert.equal(currentURL(), '/');
    assert.ok($('.ajax-get').length === 1, 'ajax-get component is rendered');
  });

  click('button:contains(Load Data)');

  andThen(function(){
    assert.equal($('.ajax-get li:eq(0)').text(), 'Foo');
    assert.equal($('.ajax-get li:eq(1)').text(), 'Bar');
    assert.equal($('.ajax-get li:eq(2)').text(), 'Baz');
  });
});

Integration Test

import hbs from 'htmlbars-inline-precompile';
import {
  moduleForComponent,
  test
} from 'ember-qunit';

import Pretender from 'pretender';
import json from 'dummy/tests/helpers/json';
import wait from 'ember-test-helpers/wait';

let server;
moduleForComponent('ajax-get', {
  integration: true,
  beforeEach() {
    server = new Pretender();
  },
  afterEach() {
    server.shutdown();
  }
});

test('clicking Load Data loads data', function(assert) {
  const PAYLOAD = [{ title: 'Foo' }, { title: 'Bar' }, { title: 'Baz' }];

  server.get('/foo', json(200, PAYLOAD), 300);

  this.render(hbs`
    {{#ajax-get url="/foo" as |data isLoaded|}}
      {{#if isLoaded}}
        <ul>
        {{#each data as |post|}}
          <li>{{post.title}}</li>
        {{/each}}
        </ul>
      {{else}}
        <button {{action data}}>Load Data</button>
      {{/if}}
    {{/ajax-get}}
  `);

  this.$(`.ajax-get button`).click();

  return wait().then(function(){
    assert.equal($('.ajax-get li:eq(0)').text(), 'Foo');
    assert.equal($('.ajax-get li:eq(1)').text(), 'Bar');
    assert.equal($('.ajax-get li:eq(2)').text(), 'Baz');
  });
});

Notice, the wait() helper. It waits for Ajax requests to complete before continuing.

Upgrade from ic-ajax

This addon was written to supersede ic-ajax and ember-cli-ic-ajax addon because ic-ajax includes features and practices that are no longer considered best practices.

In most cases, it should be fairly easy to upgrade to ember-ajax. To aid you in the migration process, I would recommend that you follow the following steps.

1. Install ember-ajax with ember install ember-ajax
2. Search and replace ic-ajax with ember-ajax
3. Run your test suite and look for ic-ajax related deprecations
4. Refactor your code to eliminate the deprecations.
5. Uninstall ic-ajax with npm uninstall --save-dev ember-cli-ic-ajax

Here is a list of notable changes that you need to consider when refactoring.

• ic-ajax is used by importing ic-ajax into a module. ember-ajax is used by injecting ajax service into a route or component.
• ic-ajax error handler returns a hash with { jqXHR, textStatus, errorThrown }. ember-ajax returns an error object that's an instance of AjaxError. error object will be either AjaxError with error.status or one of the error types listed above.
• When you import ajax from 'ic-ajax', ajax function will resolve to payload, same way as ajax.request. import raw from 'ic-ajax/raw' resolves to raw jqXHR object with payload on response property.

Installation

As an addon

• ember install ember-ajax

For development

• git clone this repository
• npm install
• bower install

Running

• ember server
• Visit your app at http://localhost:4200.

Running Tests

• ember test
• ember test --server

Building

• ember build

For more information on using ember-cli, visit http://www.ember-cli.com/.

Why an Ajax Service?

We need a singleton mechanism for making Ajax requests because currently many Ember applications have at least two ways to talk to backend APIs. With Ember Data, RESTAdapter#ajax offers the ability to specify custom headers and good error reporting. When making requests that don't require Ember Data, getting the same features is difficult because ic-ajax and Ember.$.ajax don't offer any interfaces that can automatically set headers based on property of another service (like a session service).

The idea with this addon is to provide a service that can be used by both Ember Data and on ad-hoc bases and provides consistent interface for making Ajax requests.

Special Thanks

This addon was based on ajax handing in Ember Data's Adapter.