/**
Extends IO to provide an alternate, Flash transport, for making
cross-domain requests.
@module io
@submodule io-xdr
@for IO
**/
/**
Fires when the XDR transport is ready for use.
@event io:xdrReady
**/
var E_XDR_READY = Y.publish('io:xdrReady', { fireOnce: true }),
/**
Map of stored configuration objects when using
Flash as the transport for cross-domain requests.
@property _cB
@private
@type {Object}
**/
_cB = {},
/**
Map of transaction simulated readyState values
when XDomainRequest is the transport.
@property _rS
@private
@type {Object}
**/
_rS = {},
// Document reference
d = Y.config.doc,
// Window reference
w = Y.config.win,
// XDomainRequest cross-origin request detection
xdr = w && w.XDomainRequest;
/**
Method that creates the Flash transport swf.
@method _swf
@private
@param {String} uri - location of io.swf.
@param {String} yid - YUI sandbox id.
@param {String} yid - IO instance id.
**/
function _swf(uri, yid, uid) {
var o = '<object id="io_swf" type="application/x-shockwave-flash" data="' +
uri + '" width="0" height="0">' +
'<param name="movie" value="' + uri + '">' +
'<param name="FlashVars" value="yid=' + yid + '&uid=' + uid + '">' +
'<param name="allowScriptAccess" value="always">' +
'</object>',
c = d.createElement('div');
d.body.appendChild(c);
c.innerHTML = o;
}
/**
Creates a response object for XDR transactions, for success
and failure cases.
@method _data
@private
@param {Object} o - Transaction object generated by _create() in io-base.
@param {Boolean} u - Configuration xdr.use.
@param {Boolean} d - Configuration xdr.dataType.
@return {Object}
**/
function _data(o, u, d) {
if (u === 'flash') {
o.c.responseText = decodeURI(o.c.responseText);
}
if (d === 'xml') {
o.c.responseXML = Y.DataType.XML.parse(o.c.responseText);
}
return o;
}
/**
Method for intiating an XDR transaction abort.
@method _abort
@private
@param {Object} o - Transaction object generated by _create() in io-base.
@param {Object} c - configuration object for the transaction.
**/
function _abort(o, c) {
return o.c.abort(o.id, c);
}
/**
Method for determining if an XDR transaction has completed
and all data are received.
@method _isInProgress
@private
@param {Object} o - Transaction object generated by _create() in io-base.
**/
function _isInProgress(o) {
return xdr ? _rS[o.id] !== 4 : o.c.isInProgress(o.id);
}
Y.mix(Y.IO.prototype, {
/**
Map of io transports.
@property _transport
@private
@type {Object}
**/
_transport: {},
/**
Sets event handlers for XDomainRequest transactions.
@method _ieEvt
@private
@static
@param {Object} o - Transaction object generated by _create() in io-base.
@param {Object} c - configuration object for the transaction.
**/
_ieEvt: function(o, c) {
var io = this,
i = o.id,
t = 'timeout';
o.c.onprogress = function() { _rS[i] = 3; };
o.c.onload = function() {
_rS[i] = 4;
io.xdrResponse('success', o, c);
};
o.c.onerror = function() {
_rS[i] = 4;
io.xdrResponse('failure', o, c);
};
if (c[t]) {
o.c.ontimeout = function() {
_rS[i] = 4;
io.xdrResponse(t, o, c);
};
o.c[t] = c[t];
}
},
/**
Method for accessing the transport's interface for making a
cross-domain transaction.
@method xdr
@param {String} uri - qualified path to transaction resource.
@param {Object} o - Transaction object generated by _create() in io-base.
@param {Object} c - configuration object for the transaction.
**/
xdr: function(uri, o, c) {
var io = this;
if (c.xdr.use === 'flash') {
// The configuration object cannot be serialized safely
// across Flash's ExternalInterface.
_cB[o.id] = c;
w.setTimeout(function() {
try {
o.c.send(uri, { id: o.id,
uid: o.uid,
method: c.method,
data: c.data,
headers: c.headers });
}
catch(e) {
io.xdrResponse('transport error', o, c);
delete _cB[o.id];
}
}, Y.io.xdr.delay);
}
else if (xdr) {
io._ieEvt(o, c);
o.c.open(c.method || 'GET', uri);
o.c.send(c.data);
}
else {
o.c.send(uri, o, c);
}
return {
id: o.id,
abort: function() {
return o.c ? _abort(o, c) : false;
},
isInProgress: function() {
return o.c ? _isInProgress(o.id) : false;
},
io: io
};
},
/**
Response controller for cross-domain requests when using the
Flash transport or IE8's XDomainRequest object.
@method xdrResponse
@param {String} e Event name
@param {Object} o Transaction object generated by _create() in io-base.
@param {Object} c Configuration object for the transaction.
@return {Object}
**/
xdrResponse: function(e, o, c) {
c = _cB[o.id] ? _cB[o.id] : c;
var io = this,
m = xdr ? _rS : _cB,
u = c.xdr.use,
d = c.xdr.dataType;
switch (e) {
case 'start':
io.start(o, c);
break;
//case 'complete':
//This case is not used by Flash or XDomainRequest.
//io.complete(o, c);
//break;
case 'success':
io.success(_data(o, u, d), c);
delete m[o.id];
break;
case 'timeout':
case 'abort':
case 'transport error':
o.c = { status: 0, statusText: e };
case 'failure':
io.failure(_data(o, u, d), c);
delete m[o.id];
break;
}
},
/**
Fires event "io:xdrReady"
@method _xdrReady
@private
@param {Number} yid - YUI sandbox id.
@param {Number} uid - IO instance id.
**/
_xdrReady: function(yid, uid) {
Y.fire(E_XDR_READY, yid, uid);
},
/**
Initializes the desired transport.
@method transport
@param {Object} o - object of transport configurations.
**/
transport: function(c) {
if (c.id === 'flash') {
_swf(Y.UA.ie ? c.src + '?d=' + new Date().valueOf().toString() : c.src, Y.id, c.uid);
Y.IO.transports.flash = function() { return d.getElementById('io_swf'); };
}
}
});
/**
Fires event "io:xdrReady"
@method xdrReady
@protected
@static
@param {Number} yid - YUI sandbox id.
@param {Number} uid - IO instance id.
**/
Y.io.xdrReady = function(yid, uid){
var io = Y.io._map[uid];
Y.io.xdr.delay = 0;
io._xdrReady.apply(io, [yid, uid]);
};
Y.io.xdrResponse = function(e, o, c){
var io = Y.io._map[o.uid];
io.xdrResponse.apply(io, [e, o, c]);
};
Y.io.transport = function(c){
var io = Y.io._map['io:0'] || new Y.IO();
c.uid = io._uid;
io.transport.apply(io, [c]);
};
/**
Delay value to calling the Flash transport, in the
event io.swf has not finished loading. Once the E_XDR_READY
event is fired, this value will be set to 0.
@property delay
@static
@type {Number}
**/
Y.io.xdr = { delay : 100 };
