File size: 4,877 Bytes
19605ab |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 |
/**
* Module requirements.
*/
var Polling = require('./polling');
var inherit = require('component-inherit');
/**
* Module exports.
*/
module.exports = JSONPPolling;
/**
* Cached regular expressions.
*/
var rNewline = /\n/g;
var rEscapedNewline = /\\n/g;
/**
* Global JSONP callbacks.
*/
var callbacks;
/**
* Noop.
*/
function empty () { }
/**
* JSONP Polling constructor.
*
* @param {Object} opts.
* @api public
*/
function JSONPPolling (opts) {
Polling.call(this, opts);
this.query = this.query || {};
// define global callbacks array if not present
// we do this here (lazily) to avoid unneeded global pollution
if (!callbacks) {
// we need to consider multiple engines in the same page
if (!global.___eio) global.___eio = [];
callbacks = global.___eio;
}
// callback identifier
this.index = callbacks.length;
// add callback to jsonp global
var self = this;
callbacks.push(function (msg) {
self.onData(msg);
});
// append to query string
this.query.j = this.index;
// prevent spurious errors from being emitted when the window is unloaded
if (global.document && global.addEventListener) {
global.addEventListener('beforeunload', function () {
if (self.script) self.script.onerror = empty;
}, false);
}
}
/**
* Inherits from Polling.
*/
inherit(JSONPPolling, Polling);
/*
* JSONP only supports binary as base64 encoded strings
*/
JSONPPolling.prototype.supportsBinary = false;
/**
* Closes the socket.
*
* @api private
*/
JSONPPolling.prototype.doClose = function () {
if (this.script) {
this.script.parentNode.removeChild(this.script);
this.script = null;
}
if (this.form) {
this.form.parentNode.removeChild(this.form);
this.form = null;
this.iframe = null;
}
Polling.prototype.doClose.call(this);
};
/**
* Starts a poll cycle.
*
* @api private
*/
JSONPPolling.prototype.doPoll = function () {
var self = this;
var script = document.createElement('script');
if (this.script) {
this.script.parentNode.removeChild(this.script);
this.script = null;
}
script.async = true;
script.src = this.uri();
script.onerror = function (e) {
self.onError('jsonp poll error', e);
};
var insertAt = document.getElementsByTagName('script')[0];
if (insertAt) {
insertAt.parentNode.insertBefore(script, insertAt);
} else {
(document.head || document.body).appendChild(script);
}
this.script = script;
var isUAgecko = 'undefined' !== typeof navigator && /gecko/i.test(navigator.userAgent);
if (isUAgecko) {
setTimeout(function () {
var iframe = document.createElement('iframe');
document.body.appendChild(iframe);
document.body.removeChild(iframe);
}, 100);
}
};
/**
* Writes with a hidden iframe.
*
* @param {String} data to send
* @param {Function} called upon flush.
* @api private
*/
JSONPPolling.prototype.doWrite = function (data, fn) {
var self = this;
if (!this.form) {
var form = document.createElement('form');
var area = document.createElement('textarea');
var id = this.iframeId = 'eio_iframe_' + this.index;
var iframe;
form.className = 'socketio';
form.style.position = 'absolute';
form.style.top = '-1000px';
form.style.left = '-1000px';
form.target = id;
form.method = 'POST';
form.setAttribute('accept-charset', 'utf-8');
area.name = 'd';
form.appendChild(area);
document.body.appendChild(form);
this.form = form;
this.area = area;
}
this.form.action = this.uri();
function complete () {
initIframe();
fn();
}
function initIframe () {
if (self.iframe) {
try {
self.form.removeChild(self.iframe);
} catch (e) {
self.onError('jsonp polling iframe removal error', e);
}
}
try {
// ie6 dynamic iframes with target="" support (thanks Chris Lambacher)
var html = '<iframe src="javascript:0" name="' + self.iframeId + '">';
iframe = document.createElement(html);
} catch (e) {
iframe = document.createElement('iframe');
iframe.name = self.iframeId;
iframe.src = 'javascript:0';
}
iframe.id = self.iframeId;
self.form.appendChild(iframe);
self.iframe = iframe;
}
initIframe();
// escape \n to prevent it from being converted into \r\n by some UAs
// double escaping is required for escaped new lines because unescaping of new lines can be done safely on server-side
data = data.replace(rEscapedNewline, '\\\n');
this.area.value = data.replace(rNewline, '\\n');
try {
this.form.submit();
} catch (e) {}
if (this.iframe.attachEvent) {
this.iframe.onreadystatechange = function () {
if (self.iframe.readyState === 'complete') {
complete();
}
};
} else {
this.iframe.onload = complete;
}
};
|