ExtJS+Jquery实现文件上传

jQuery.extend({

createUploadIframe: function(id, uri){

var frameId = 'jQuery' + id;

if(window.ActiveXObject) {
var io = document.createElement('<iframe id="' + frameId + '" name="' + frameId + '" />');

if(typeof uri== 'boolean'){
io.src = 'javascript:false';
}
else if(typeof uri== 'string'){
io.src = uri;
}
}
else {
var io = document.createElement('iframe');
io.id = frameId;
io.name = frameId;
}

io.style.position = 'absolute';
io.style.top = '-1000px';
io.style.left = '-1000px';

document.body.appendChild(io);

return io

},

ajaxUpload: function(s) {
// TODO introduce global settings, allowing the client to modify them for all requests, not only timeout
s = jQuery.extend({}, jQuery.ajaxSettings, s);

var id = new Date().getTime()
io = jQuery.createUploadIframe(id, s.secureuri)

// Watch for a new set of requests
if ( s.global && ! jQuery.active++ )
jQuery.event.trigger( "ajaxStart" );

var requestDone = false;

// Create the request object
var xml = {}
if ( s.global )
jQuery.event.trigger("ajaxSend", [xml, s]);

// Wait for a response to come back
var uploadCallback = function(isTimeout){
try {
xml.responseText = io.contentWindow.document.body?io.contentWindow.document.body.innerHTML:null;
xml.responseXML = io.contentWindow.document.XMLDocument?io.contentWindow.document.XMLDocument:io.contentWindow.document;
}
catch(e){}
if ( xml || isTimeout == "timeout") {
requestDone = true;
var status;
try {
status = isTimeout != "timeout" ? "success" : "error";
// Make sure that the request was successful or notmodified
if ( status != "error" ) {
// process the data (runs the xml through httpData regardless of callback)
var data = jQuery.uploadHttpData( xml, s.dataType );

// If a local callback was specified, fire it and pass it the data
if ( s.success )
s.success( data, status );

// Fire the global callback
if( s.global )
jQuery.event.trigger( "ajaxSuccess", [xml, s] );
} else
jQuery.handleError(s, xml, status);
} catch(e) {
status = "error";
jQuery.handleError(s, xml, status, e);
}

// The request was completed
if( s.global )
jQuery.event.trigger( "ajaxComplete", [xml, s] );

// Handle the global AJAX counter
if ( s.global && ! --jQuery.active )
jQuery.event.trigger( "ajaxStop" );

// Process result
if ( s.complete )
s.complete(xml, status);

// jQuery(io).unbind()

// setTimeout(function(){ document.body.removeChild(io); }, 100)

xml = null

}
}
// Timeout checker
if ( s.timeout > 0 ) {
setTimeout(function(){
// Check to see if the request is still happening
if( !requestDone ) uploadCallback( "timeout" );
}, s.timeout);
}
try {
var frameId = 'jQuery' + id;
var io = document.getElementById(frameId);
// Initialize the HTML form properties in case they are
// not defined in the HTML form.
s.uploadform.action = s.url;
s.uploadform.method = 'POST';
s.uploadform.target = frameId;

// Add extra data that may have been already passed.
if (s.data) {
var oEls = s.data.split('&');
for (var i=0; i < oEls.length; i++ ){
var thisEl = oEls[i].split('=');
var thisFormEl = document.createElement('input');
thisFormEl.type = 'hidden';
thisFormEl.name = thisEl[0];
thisFormEl.value = thisEl[1];
s.uploadform.appendChild(thisFormEl);
}

}

if(s.uploadform.encoding){
// IE does not respect property enctype for HTML forms.
// Instead use property encoding.
s.uploadform.encoding = 'multipart/form-data';
}
else{
s.uploadform.enctype = 'multipart/form-data';
}

s.uploadform.submit();

} catch(e) {
jQuery.handleError(s, xml, null, e);
}

if(window.attachEvent){
io.attachEvent('onload', uploadCallback);
}
else{
io.addEventListener('load', uploadCallback, false);
}

return {abort: function () {}};

},

uploadHttpData: function( r, type ) {
var data = !type;
data = type == "xml" || data ? r.responseXML : r.responseText;
// If the type is "script", eval it in global context
if ( type == "script" )
jQuery.globalEval( data );

// Get the JavaScript object, if JSON is used.
if ( type == "json" )
eval( "data = " + data );

// evaluate scripts within html
if ( type == "html" )
jQuery("<div>").html(data).evalScripts();

return data;
}
})

Ext.lib.Ajax.formRequest = function(form, uri, cb, data, isUpload, sslUri){
var createComplete = function(cb){
return function(xhr, status){
if((status == 'error' || status == 'timeout') && cb.failure){
cb.failure.call(cb.scope||window, {
responseText: xhr.responseText,
responseXML : xhr.responseXML,
argument: cb.argument
});
}else if(cb.success){
cb.success.call(cb.scope||window, {
responseText: xhr.responseText,
responseXML : xhr.responseXML,
argument: cb.argument
});
}
};
};

if (isUpload) {
jQuery.ajaxUpload({
uploadform: form,
data: data,
url: uri,
secureuri: sslUri,
complete: createComplete(cb)
});
} else {
jQuery.ajax({
type: Ext.getDom(form).method ||'POST',
url: uri,
data: jQuery(form).formSerialize()+(data?'&'+data:''),
timeout: cb.timeout,
complete: createComplete(cb)
});
}
};