Jeffarese Jeffarese - 4 months ago 10
AngularJS Question

Services with ES6 (AngularJS)

I'm having problems accessing Angular built-in services such as $http when creating a service with ES6.

For example, I'm creating a "ResultsFinder" service that will do an AJAX call and then do some stuff.
The problem is that I only have access to $http on the constructor (if I pass it as an argument), but not on other methods (such as getResults).

See this code example:



(() => {
'use strict';

class ResultsFinder {
constructor($http) {}
getResults() {
return 'ResultsFinder';
}
}

/**
* @ngdoc service
* @name itemManager.service:ResultsFinder
*
* @description
*
*/
angular
.module('itemManager')
.service('ResultsFinder', ResultsFinder);
}());





Inside getResults I don't have access to $http. In order to have access I should do something that I don't feel right like this:



(() => {
'use strict';

class ResultsFinder {
constructor($http) {
this.$http = $http;
}
getResults() {
// Here I have access to this.$http
return 'ResultsFinder';
}
}

/**
* @ngdoc service
* @name itemManager.service:ResultsFinder
*
* @description
*
*/
angular
.module('itemManager')
.service('ResultsFinder', ResultsFinder);
}());





Anyone can give me some advice about the proper way to handle this?

Answer

You need to use this.$http inside your getResults method.

(() => {
  'use strict';
      
class ResultsFinder {
	
    static $inject = ['$http'];   
    constructor($http) {
        this.$http = $http;
    }
		
    getResults() {
        return this.$http.get('/foo/bar/');
    }
}

  /**
   * @ngdoc service
   * @name itemManager.service:ResultsFinder
   *
   * @description
   *
   */
  angular
    .module('itemManager')
    .service('ResultsFinder', ResultsFinder);
}());

As a side note, I added a static $inject "annotation" to your class. This is a best practice if you are not using something like ngAnnotate. It also makes it easier to change out implementations by only changing the $inject values.

If you are a ES5 developer it may help to think about how this would look in ES5

ResultsFinder.$inject = ['$http'];
var ResultsFinder = function($http) {
    this.$http = $http;
}

ResultsFinder.prototype.getResults = function() {
    return this.$http.get('/foo/bar/');
}