/**
Extends the IO to enable file uploads, with HTML forms
using an iframe as the transport medium.
@module io
@submodule io-upload-iframe
@for IO
**/
var w = Y.config.win,
d = Y.config.doc,
_std = (d.documentMode && d.documentMode >= 8),
_d = decodeURIComponent,
_end = Y.IO.prototype.end;
/**
* Creates the iframe transported used in file upload
* transactions, and binds the response event handler.
*
* @method _cFrame
* @private
* @param {Object} o Transaction object generated by _create().
* @param {Object} c Configuration object passed to YUI.io().
* @param {Object} io
*/
function _cFrame(o, c, io) {
var i = Y.Node.create('<iframe id="io_iframe' + o.id + '" name="io_iframe' + 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() { io._uploadComplete(o, c); }, '#io_iframe' + o.id);
}
/**
* Removes the iframe transport used in the file upload
* transaction.
*
* @method _dFrame
* @private
* @param {Number} id The transaction ID used in the iframe's creation.
*/
function _dFrame(id) {
Y.Event.purgeElement('#io_iframe' + id, false);
Y.one('body').removeChild(Y.one('#io_iframe' + id));
Y.log('The iframe transport for transaction ' + id + ' has been destroyed.', 'info', 'io');
}
Y.mix(Y.IO.prototype, {
/**
* Parses the POST data object and creates hidden form elements
* for each key-value, and appends them to the HTML form object.
* @method _addData
* @private
* @static
* @param {Object} f HTML form object.
* @param {String} s The key-value POST data.
* @return {Array} o Array of created fields.
*/
_addData: function(f, s) {
// Serialize an object into a key-value string using
// querystring-stringify-simple.
if (Y.Lang.isObject(s)) {
s = Y.QueryString.stringify(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;
},
/**
* Removes the custom fields created to pass additional POST
* data, along with the HTML form fields.
* @method _removeData
* @private
* @static
* @param {Object} f HTML form object.
* @param {Object} o HTML form fields created from configuration.data.
*/
_removeData: function(f, o) {
var i, l;
for (i = 0, l = o.length; i < l; i++) {
f.removeChild(o[i]);
}
},
/**
* 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.
*/
_setAttrs: function(f, id, uri) {
// Track original HTML form attribute values.
this._originalFormAttrs = {
action: f.getAttribute('action'),
target: f.getAttribute('target')
};
f.setAttribute('action', uri);
f.setAttribute('method', 'POST');
f.setAttribute('target', 'io_iframe' + id );
f.setAttribute(Y.UA.ie && !_std ? 'encoding' : 'enctype', 'multipart/form-data');
},
/**
* 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.
*/
_resetAttrs: function(f, a) {
Y.Object.each(a, function(v, p) {
if (v) {
f.setAttribute(p, v);
}
else {
f.removeAttribute(p);
}
});
},
/**
* Starts timeout count if the configuration object
* has a defined timeout property.
*
* @method _startUploadTimeout
* @private
* @static
* @param {Object} o Transaction object generated by _create().
* @param {Object} c Configuration object passed to YUI.io().
*/
_startUploadTimeout: function(o, c) {
var io = this;
io._timeout[o.id] = w.setTimeout(
function() {
o.status = 0;
o.statusText = 'timeout';
io.complete(o, c);
io.end(o, c);
Y.log('Transaction ' + o.id + ' timeout.', 'info', 'io');
}, c.timeout);
},
/**
* Clears the timeout interval started by _startUploadTimeout().
* @method _clearUploadTimeout
* @private
* @static
* @param {Number} id - Transaction ID.
*/
_clearUploadTimeout: function(id) {
var io = this;
w.clearTimeout(io._timeout[id]);
delete io._timeout[id];
},
/**
* Bound to the iframe's Load event and processes
* the response data.
* @method _uploadComplete
* @private
* @static
* @param {Object} o The transaction object
* @param {Object} c Configuration object for the transaction.
*/
_uploadComplete: function(o, c) {
var io = this,
d = Y.one('#io_iframe' + o.id).get('contentWindow.document'),
b = d.one('body'),
p;
if (c.timeout) {
io._clearUploadTimeout(o.id);
}
try {
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');
}
}
catch (e) {
o.e = "upload failure";
}
io.complete(o, c);
io.end(o, c);
// The transaction is complete, so call _dFrame to remove
// the event listener bound to the iframe transport, and then
// destroy the iframe.
w.setTimeout( function() { _dFrame(o.id); }, 0);
},
/**
* Uploads HTML form data, inclusive of files/attachments,
* using the iframe created in _create to facilitate the transaction.
* @method _upload
* @private
* @static
* @param {Object} o The transaction object
* @param {Object} uri Qualified path to transaction resource.
* @param {Object} c Configuration object for the transaction.
*/
_upload: function(o, uri, c) {
var io = this,
f = (typeof c.form.id === 'string') ? d.getElementById(c.form.id) : c.form.id,
fields;
// Initialize the HTML form properties in case they are
// not defined in the HTML form.
io._setAttrs(f, o.id, uri);
if (c.data) {
fields = io._addData(f, c.data);
}
// Start polling if a callback is present and the timeout
// property has been defined.
if (c.timeout) {
io._startUploadTimeout(o, c);
Y.log('Transaction timeout started for transaction ' + o.id + '.', 'info', 'io');
}
// Start file upload.
f.submit();
io.start(o, c);
if (c.data) {
io._removeData(f, fields);
}
return {
id: o.id,
abort: function() {
o.status = 0;
o.statusText = 'abort';
if (Y.one('#io_iframe' + o.id)) {
_dFrame(o.id);
io.complete(o, c);
io.end(o, 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('#io_iframe' + o.id) ? true : false;
},
io: io
};
},
upload: function(o, uri, c) {
_cFrame(o, c, this);
return this._upload(o, uri, c);
},
end: function(transaction, config) {
var form, io;
if (config) {
form = config.form;
if (form && form.upload) {
io = this;
// Restore HTML form attributes to their original values.
form = (typeof form.id === 'string') ? d.getElementById(form.id) : form.id;
// Check whether the form still exists before resetting it.
if (form) {
io._resetAttrs(form, this._originalFormAttrs);
}
}
}
return _end.call(this, transaction, config);
}
}, true);