/**
* Extends the IO base class to enable file uploads, with HTML forms,
* using an iframe as the transport medium.
* @module io
* @submodule io-upload-iframe
*/
var w = Y.config.win,
d = Y.config.doc,
_std = (d.documentMode && d.documentMode >= 8),
_d = decodeURIComponent;
/**
* @description Parses the POST data object and creates hidden form elements
* for each key-value, and appends them to the HTML form object.
* @method appendData
* @private
* @static
* @param {object} f HTML form object.
* @param {string} s The key-value POST data.
* @return {array} e Array of created fields.
*/
function _addData(f, s) {
var o = [],
m = s.split('='),
i, l;
for (i = 0, l = m.length - 1; i < l; i++) {
o[i] = d.createElement('input');
o[i].type = 'hidden';
o[i].name = _d(m[i].substring(m[i].lastIndexOf('&') + 1));
o[i].value = (i + 1 === l) ? _d(m[i + 1]) : _d(m[i + 1].substring(0, (m[i + 1].lastIndexOf('&'))));
f.appendChild(o[i]);
Y.log('key: ' + o[i].name + ' and value: ' + o[i].value + ' added as form data.', 'info', 'io');
}
return o;
}
/**
* @description Removes the custom fields created to pass additional POST
* data, along with the HTML form fields.
* @method f
* @private
* @static
* @param {object} f HTML form object.
* @param {object} o HTML form fields created from configuration.data.
* @return {void}
*/
function _removeData(f, o) {
var i, l;
for (i = 0, l = o.length; i < l; i++) {
f.removeChild(o[i]);
}
}
/**
* @description Sets the appropriate attributes and values to the HTML
* form, in preparation of a file upload transaction.
* @method _setAttrs
* @private
* @static
* @param {object} f HTML form object.
* @param {object} id The Transaction ID.
* @param {object} uri Qualified path to transaction resource.
* @return {void}
*/
function _setAttrs(f, id, uri) {
f.setAttribute('action', uri);
f.setAttribute('method', 'POST');
f.setAttribute('target', 'ioupload' + id );
f.setAttribute(Y.UA.ie && !_std ? 'encoding' : 'enctype', 'multipart/form-data');
}
/**
* @description Reset the HTML form attributes to their original values.
* @method _resetAttrs
* @private
* @static
* @param {object} f HTML form object.
* @param {object} a Object of original attributes.
* @return {void}
*/
function _resetAttrs(f, a){
var p;
for (p in a) {
if (a.hasOwnProperty(p)) {
if (a[p]) {
f.setAttribute(p, f[p]);
}
else {
f.removeAttribute(p);
}
}
}
}
/**
* @description Starts timeout count if the configuration object
* has a defined timeout property.
*
* @method _startTimeout
* @private
* @static
* @param {object} o Transaction object generated by _create().
* @param {object} c Configuration object passed to YUI.io().
* @return {void}
*/
function _startTimeout(o, c) {
Y.io._timeout[o.id] = w.setTimeout(
function() {
var r = { id: o.id, status: 'timeout' };
Y.io.complete(r, c);
Y.io.end(r, c);
Y.log('Transaction ' + o.id + ' timeout.', 'info', 'io');
}, c.timeout);
}
/**
* @description Clears the timeout interval started by _startTimeout().
* @method _clearTimeout
* @private
* @static
* @param {number} id - Transaction ID.
* @return {void}
*/
function _clearTimeout(id) {
w.clearTimeout(Y.io._timeout[id]);
delete Y.io._timeout[id];
}
/**
* @description
* @method _destroy
* @private
* @static
* @param {o} o The transaction object
* @param {object} uri Qualified path to transaction resource.
* @param {object} c Configuration object for the transaction.
* @return {void}
*/
function _destroy(id) {
Y.Event.purgeElement('#ioupload' + id, false);
Y.one('body').removeChild(Y.one('#ioupload' + id));
Y.log('The iframe transport for transaction ' + id + ' has been destroyed.', 'info', 'io');
}
/**
* @description Bound to the iframe's Load event and processes
* the response data.
* @method _handle
* @private
* @static
* @param {o} o The transaction object
* @param {object} c Configuration object for the transaction.
* @return {void}
*/
function _handle(o, c) {
var d = Y.one('#ioupload' + o.id).get('contentWindow.document'),
b = d.one('body'),
p;
if (c.timeout) {
_clearTimeout(o.id);
}
if (b) {
// When a response Content-Type of "text/plain" is used, Firefox and Safari
// will wrap the response string with <pre></pre>.
p = b.one('pre:first-child');
o.c.responseText = p ? p.get('text') : b.get('text');
Y.log('The responseText value for transaction ' + o.id + ' is: ' + o.c.responseText + '.', 'info', 'io');
}
else {
o.c.responseXML = d._node;
Y.log('The response for transaction ' + o.id + ' is an XML document.', 'info', 'io');
}
Y.io.complete(o, c);
Y.io.end(o, c);
// The transaction is complete, so call _destroy to remove
// the event listener bound to the iframe transport, and then
// destroy the iframe.
w.setTimeout( function() { _destroy(o.id); }, 0);
}
/**
* @description Creates the iframe transported used in file upload
* transactions, and binds the response event handler.
*
* @method _create
* @private
* @static
* @param {object} o Transaction object generated by _create().
* @param {object} c Configuration object passed to YUI.io().
* @return {void}
*/
function _create(o, c) {
var i = Y.Node.create('<iframe id="ioupload' + o.id + '" name="ioupload' + o.id + '" />');
i._node.style.position = 'absolute';
i._node.style.top = '-1000px';
i._node.style.left = '-1000px';
Y.one('body').appendChild(i);
// Bind the onload handler to the iframe to detect the file upload response.
Y.on("load", function() { _handle(o, c); }, '#ioupload' + o.id);
}
/**
* @description Uploads HTML form data, inclusive of files/attachments,
* using the iframe created in _create to facilitate the transaction.
* @method _upload
* @private
* @static
* @param {o} o The transaction object
* @param {object} uri Qualified path to transaction resource.
* @param {object} c Configuration object for the transaction.
* @return {void}
*/
function _send(o, uri, c) {
var f = (typeof c.form.id === 'string') ? d.getElementById(c.form.id) : c.form.id,
fields,
// Track original HTML form attribute values.
attr = {
action: f.getAttribute('action'),
target: f.getAttribute('target')
};
// Initialize the HTML form properties in case they are
// not defined in the HTML form.
_setAttrs(f, o.id, uri);
if (c.data) {
fields = _addData(f, c.data);
}
// Start polling if a callback is present and the timeout
// property has been defined.
if (c.timeout) {
_startTimeout(o, c);
Y.log('Transaction timeout started for transaction ' + o.id + '.', 'info', 'io');
}
// Start file upload.
f.submit();
Y.io.start(o.id, c);
if (c.data) {
_removeData(f, fields);
}
// Restore HTML form attributes to their original values.
_resetAttrs(f, attr);
return {
id: o.id,
abort: function() {
var r = { id: o.id, status: 'abort' };
if (Y.one('#ioupload' + o.id)) {
_destroy(o.id);
Y.io.complete(r, c);
Y.io.end(r, c);
Y.log('Transaction ' + o.id + ' aborted.', 'info', 'io');
}
else {
Y.log('Attempted to abort transaction ' + o.id + ' but transaction has completed.', 'warn', 'io');
return false;
}
},
isInProgress: function() {
return Y.one('#ioupload' + o.id) ? true : false;
}
};
}
Y.mix(Y.io, {
upload: function(o, uri, c) {
_create(o, c);
return _send(o, uri, c);
}
});