eccothedolphin / angular-xhr-access

AngularJS service for getting access to a native XHR object used by $htpp service

#Angular XHR Access

---

Motivation

AngularJS framework provides $http service for accessing HTTP servers. As for now, this service neither supports progress notifications, nor provides access to the underlying XHR object. This module provides services that allow you to get access to the underling XHR and thus enables you to receive progress notification or, for example, to abort already running request.

NOTE: Although the XHR object is a standard, there are variations in its
behavior on different browsers - so use it with caution.

About

angularXhrAccess is a module for the AngularJS framework. It provides the following services:

• XhrAccessService - gives you the ability to access XHR instance that was created by $http service.
• XhrProgressService - provides you with "quick and dirty" way to receive progress notification for your ajax requests.

##How this module works

Its a hack - but it helps to get the job done :). That being said, you should use this module only if you know what you are doing.

1. Current AngularJS implementation uses window.XMLHttpRequest to create XHR for $http service. This module overrides this global object with a tiny wrapper. When angular tries to create xhr it creates this wrapper instead, and upon creation this wrapper monkey-patches open method of original xhr to inject some custom logic.

2. When http service tries to call open method of its xhr object, it actually calls our monkey-patched version of this method, which in turn (after our custom logic is executed) calls original.

3. This custom logic mentioned above does the following:

4. It searches for a specific pattern in a url.

5. If url contains this specific pattern it removes this pattern from a url and then calls callbacks corresponding to this pattern.

6. To provide callbacks and modify original url you must use services that this module provides.

##Usage

XHR access:

angular.module('app', [
  'angularXhrAccess'
]).run([
  '$http',
  '$log',
  'XhrAccessService',
  function ($http, $log, xhra) {
    'use strict';
    var url = 'https://api.github.com/';
    //modify url and provide callback
    //NOTE: URL WILL BE RESTORED TO ORIGINAL STATE BEFORE ACTUAL AJAX CALL
    url = xhra.hookupUrl(url, function (xhr) {
      //here we have access to xhr object
      $log.log('your XHR object:', xhr);
    });
    //make AJAX request
    $http.get(url).then(function (result) {
      $log.log(result.data);
    });
  }
});

Progress event:

angular.module('app', [
  'angularXhrAccess'
]).run([
  '$http',
  '$log',
  'XhrProgressService',
  function ($http, $log, xhrp) {
    'use strict';
    var url = 'https://api.github.com/';
    var form = new FormData();
    form.append('example_field', 'example_field');
    //modify url and provide callback
    //NOTE: URL WILL BE RESTORED TO ORIGINAL STATE BEFORE ACTUAL AJAX CALL
    url = xhrp.hookupUrl(url, function (evt) {
      //here we have access to *progress* event
      $log.log('your *progress* event:', evt);
    });
    var headers = { 'Content-Type' : undefined };
    //this request will end up with 404, but you will receive *progress* event
    $http.post(url, form, {headers : headers}).then(function (result) {
      $log.log(result.data);
    });
  }
]);

##Install

####Bower

bower install angular-xhr-access