https://static.openpetition.de/javascript/module/HttpRequest.js?1790086250

1var HttpRequest = (function() {
2	'use strict';
3
4	var HttpRequest = function(url) {
5		// Because we overwrite this.url in the get-function every GET-parameter is appended after each request.
6		// This results in broken urls after multiple calls.
7		// this.urlWithoutParameters is used to reset the url before we append the parameters.
8		this.url = url;
9		this.urlWithoutParameters = url;
10
11		this.requestHeaders = {
12			'x-requested-with': 'xmlhttprequest'
13		};
14
15		// JavaScript Events only work with DOM elements (such as a "div" or text nodes)
16		// so we create a new empty text node (which will never be added to the DOM)
17		// to bind the actual event to this node
18		var target = document.createTextNode(null);
19
20		// Pass EventTarget interface calls to DOM EventTarget object
21		this.addEventListener = target.addEventListener.bind(target);
22		this.removeEventListener = target.removeEventListener.bind(target);
23		this.dispatchEvent = target.dispatchEvent.bind(target);
24	};
25
26	/**
27	 * Make a HTTP GET request with optional query parameters
28	 *
29	 * @author Jonas Hantelmann <[email protected]>
30	 */
31	HttpRequest.prototype.get = function(payload, requestSilently) {
32		// Add the payload as query parameters to the URL
33		if (payload) {
34			this.url = this.urlWithoutParameters;		// Reset url
35			this.url += '?' + Object.keys(payload).map(function(key) {
36				return encodeURIComponent(key) + '=' + encodeURIComponent(payload[key]);
37			}).join('&');
38		}
39
40		this.send('GET', null, requestSilently);
41	};
42
43	/**
44	 * Make a HTTP POST request with an optional payload
45	 *
46	 * @author Jonas Hantelmann <[email protected]>
47	 */
48	HttpRequest.prototype.post = function(payload, requestSilently) {
49		// Set the correct content-type header if we want to pass parameters
50		if (typeof payload == 'object' && !(payload instanceof FormData)) {
51			this.addRequestHeader('content-type', 'application/x-www-form-urlencoded');
52
53			// Format the payload as urlencoded query string
54			payload = Object.keys(payload).map(function(key) {
55				return encodeURIComponent(key) + '=' + encodeURIComponent(payload[key]);
56			}).join('&');
57		}
58
59		this.send('POST', payload, requestSilently);
60	};
61
62	/**
63	 * Add a request header (key, value)
64	 *
65	 * @author Jonas Hantelmann <[email protected]>
66	 */
67	HttpRequest.prototype.addRequestHeader = function(key, value) {
68		this.requestHeaders[key.toLowerCase()] = value;
69	};
70
71	/**
72	 * Generic function to make a HTTP request with an optional payload
73	 *
74	 * @author Jonas Hantelmann <[email protected]>
75	 */
76	HttpRequest.prototype.send = function(type, payload, requestSilently) {
77		var request = new XMLHttpRequest();
78		var _this = this;
79
80		request.open(type, this.url, true);
81
82		// Set previously defined request headers
83		for (var requestHeaderName in this.requestHeaders) {
84			request.setRequestHeader(requestHeaderName, this.requestHeaders[requestHeaderName]);
85		}
86
87		request.addEventListener('readystatechange', function() {
88			if (this.readyState == XMLHttpRequest.HEADERS_RECEIVED) {
89				// If we got a JSON response, tell JavaScript to format it accordingly
90				if (/^application\/json/.test(this.getResponseHeader('Content-Type'))) {
91					request.responseType = 'json';
92				}
93			}
94		});
95
96		request.addEventListener('load', function() {
97			// Update URL in browser history/address bar after Ajax call
98			if (!requestSilently && typeof this.responseURL !== 'undefined') {
99				history.pushState(null, '', this.responseURL);
100			}
101
102			// If we got any response from the Ajax request,
103			// fire the "load" event and pass the XMLHttpRequest object
104			_this.dispatchEvent(new CustomEvent('load', {
105				detail: this
106			}));
107		});
108
109		request.addEventListener('error', function() {
110			// If the request failed (maybe the server is offline)
111			// fire the "error" event
112			_this.dispatchEvent(new CustomEvent('error'));
113		});
114
115		request.send(payload || null);
116	};
117
118	return HttpRequest;
119}());