include/javascript/yui/build/connection/connection_core-debug.js

   1 /*
   2 Copyright (c) 2009, Yahoo! Inc. All rights reserved.
   3 Code licensed under the BSD License:
   4 http://developer.yahoo.net/yui/license.txt
   5 version: 2.8.0r4
   6 */
   7 /**
   8  * The Connection Manager provides a simplified interface to the XMLHttpRequest
   9  * object.  It handles cross-browser instantiantion of XMLHttpRequest, negotiates the
  10  * interactive states and server response, returning the results to a pre-defined
  11  * callback you create.
  12  *
  13  * @namespace YAHOO.util
  14  * @module connection
  15  * @requires yahoo
  16  * @requires event
  17  */
  18
  19 /**
  20  * The Connection Manager singleton provides methods for creating and managing
  21  * asynchronous transactions.
  22  *
  23  * @class Connect
  24  */
  25
  26 YAHOO.util.Connect =
  27 {
  28   /**
  29    * @description Array of MSFT ActiveX ids for XMLHttpRequest.
  30    * @property _msxml_progid
  31    * @private
  32    * @static
  33    * @type array
  34    */
  35         _msxml_progid:[
  36                 'Microsoft.XMLHTTP',
  37                 'MSXML2.XMLHTTP.3.0',
  38                 'MSXML2.XMLHTTP'
  39                 ],
  40
  41   /**
  42    * @description Object literal of HTTP header(s)
  43    * @property _http_header
  44    * @private
  45    * @static
  46    * @type object
  47    */
  48         _http_headers:{},
  49
  50   /**
  51    * @description Determines if HTTP headers are set.
  52    * @property _has_http_headers
  53    * @private
  54    * @static
  55    * @type boolean
  56    */
  57         _has_http_headers:false,
  58
  59  /**
  60   * @description Determines if a default header of
  61   * Content-Type of 'application/x-www-form-urlencoded'
  62   * will be added to any client HTTP headers sent for POST
  63   * transactions.
  64   * @property _use_default_post_header
  65   * @private
  66   * @static
  67   * @type boolean
  68   */
  69     _use_default_post_header:true,
  70
  71  /**
  72   * @description The default header used for POST transactions.
  73   * @property _default_post_header
  74   * @private
  75   * @static
  76   * @type boolean
  77   */
  78     _default_post_header:'application/x-www-form-urlencoded; charset=UTF-8',
  79
  80  /**
  81   * @description The default header used for transactions involving the
  82   * use of HTML forms.
  83   * @property _default_form_header
  84   * @private
  85   * @static
  86   * @type boolean
  87   */
  88     _default_form_header:'application/x-www-form-urlencoded',
  89
  90  /**
  91   * @description Determines if a default header of
  92   * 'X-Requested-With: XMLHttpRequest'
  93   * will be added to each transaction.
  94   * @property _use_default_xhr_header
  95   * @private
  96   * @static
  97   * @type boolean
  98   */
  99     _use_default_xhr_header:true,
 100
 101  /**
 102   * @description The default header value for the label
 103   * "X-Requested-With".  This is sent with each
 104   * transaction, by default, to identify the
 105   * request as being made by YUI Connection Manager.
 106   * @property _default_xhr_header
 107   * @private
 108   * @static
 109   * @type boolean
 110   */
 111     _default_xhr_header:'XMLHttpRequest',
 112
 113  /**
 114   * @description Determines if custom, default headers
 115   * are set for each transaction.
 116   * @property _has_default_header
 117   * @private
 118   * @static
 119   * @type boolean
 120   */
 121     _has_default_headers:true,
 122
 123  /**
 124   * @description Determines if custom, default headers
 125   * are set for each transaction.
 126   * @property _has_default_header
 127   * @private
 128   * @static
 129   * @type boolean
 130   */
 131     _default_headers:{},
 132
 133  /**
 134   * @description Collection of polling references to the polling mechanism in handleReadyState.
 135   * @property _poll
 136   * @private
 137   * @static
 138   * @type object
 139   */
 140     _poll:{},
 141
 142  /**
 143   * @description Queue of timeout values for each transaction callback with a defined timeout value.
 144   * @property _timeOut
 145   * @private
 146   * @static
 147   * @type object
 148   */
 149     _timeOut:{},
 150
 151   /**
 152    * @description The polling frequency, in milliseconds, for HandleReadyState.
 153    * when attempting to determine a transaction's XHR readyState.
 154    * The default is 50 milliseconds.
 155    * @property _polling_interval
 156    * @private
 157    * @static
 158    * @type int
 159    */
 160      _polling_interval:50,
 161
 162   /**
 163    * @description A transaction counter that increments the transaction id for each transaction.
 164    * @property _transaction_id
 165    * @private
 166    * @static
 167    * @type int
 168    */
 169      _transaction_id:0,
 170
 171   /**
 172    * @description Custom event that fires at the start of a transaction
 173    * @property startEvent
 174    * @private
 175    * @static
 176    * @type CustomEvent
 177    */
 178         startEvent: new YAHOO.util.CustomEvent('start'),
 179
 180   /**
 181    * @description Custom event that fires when a transaction response has completed.
 182    * @property completeEvent
 183    * @private
 184    * @static
 185    * @type CustomEvent
 186    */
 187         completeEvent: new YAHOO.util.CustomEvent('complete'),
 188
 189   /**
 190    * @description Custom event that fires when handleTransactionResponse() determines a
 191    * response in the HTTP 2xx range.
 192    * @property successEvent
 193    * @private
 194    * @static
 195    * @type CustomEvent
 196    */
 197         successEvent: new YAHOO.util.CustomEvent('success'),
 198
 199   /**
 200    * @description Custom event that fires when handleTransactionResponse() determines a
 201    * response in the HTTP 4xx/5xx range.
 202    * @property failureEvent
 203    * @private
 204    * @static
 205    * @type CustomEvent
 206    */
 207         failureEvent: new YAHOO.util.CustomEvent('failure'),
 208
 209   /**
 210    * @description Custom event that fires when a transaction is successfully aborted.
 211    * @property abortEvent
 212    * @private
 213    * @static
 214    * @type CustomEvent
 215    */
 216         abortEvent: new YAHOO.util.CustomEvent('abort'),
 217
 218   /**
 219    * @description A reference table that maps callback custom events members to its specific
 220    * event name.
 221    * @property _customEvents
 222    * @private
 223    * @static
 224    * @type object
 225    */
 226         _customEvents:
 227         {
 228                 onStart:['startEvent', 'start'],
 229                 onComplete:['completeEvent', 'complete'],
 230                 onSuccess:['successEvent', 'success'],
 231                 onFailure:['failureEvent', 'failure'],
 232                 onUpload:['uploadEvent', 'upload'],
 233                 onAbort:['abortEvent', 'abort']
 234         },
 235
 236   /**
 237    * @description Member to add an ActiveX id to the existing xml_progid array.
 238    * In the event(unlikely) a new ActiveX id is introduced, it can be added
 239    * without internal code modifications.
 240    * @method setProgId
 241    * @public
 242    * @static
 243    * @param {string} id The ActiveX id to be added to initialize the XHR object.
 244    * @return void
 245    */
 246         setProgId:function(id)
 247         {
 248                 this._msxml_progid.unshift(id);
 249                 YAHOO.log('ActiveX Program Id  ' + id + ' added to _msxml_progid.', 'info', 'Connection');
 250         },
 251
 252   /**
 253    * @description Member to override the default POST header.
 254    * @method setDefaultPostHeader
 255    * @public
 256    * @static
 257    * @param {boolean} b Set and use default header - true or false .
 258    * @return void
 259    */
 260         setDefaultPostHeader:function(b)
 261         {
 262                 if(typeof b == 'string'){
 263                         this._default_post_header = b;
 264                         YAHOO.log('Default POST header set to  ' + b, 'info', 'Connection');
 265                 }
 266                 else if(typeof b == 'boolean'){
 267                         this._use_default_post_header = b;
 268                 }
 269         },
 270
 271   /**
 272    * @description Member to override the default transaction header..
 273    * @method setDefaultXhrHeader
 274    * @public
 275    * @static
 276    * @param {boolean} b Set and use default header - true or false .
 277    * @return void
 278    */
 279         setDefaultXhrHeader:function(b)
 280         {
 281                 if(typeof b == 'string'){
 282                         this._default_xhr_header = b;
 283                         YAHOO.log('Default XHR header set to  ' + b, 'info', 'Connection');
 284                 }
 285                 else{
 286                         this._use_default_xhr_header = b;
 287                 }
 288         },
 289
 290   /**
 291    * @description Member to modify the default polling interval.
 292    * @method setPollingInterval
 293    * @public
 294    * @static
 295    * @param {int} i The polling interval in milliseconds.
 296    * @return void
 297    */
 298         setPollingInterval:function(i)
 299         {
 300                 if(typeof i == 'number' && isFinite(i)){
 301                         this._polling_interval = i;
 302                         YAHOO.log('Default polling interval set to ' + i +'ms', 'info', 'Connection');
 303                 }
 304         },
 305
 306   /**
 307    * @description Instantiates a XMLHttpRequest object and returns an object with two properties:
 308    * the XMLHttpRequest instance and the transaction id.
 309    * @method createXhrObject
 310    * @private
 311    * @static
 312    * @param {int} transactionId Property containing the transaction id for this transaction.
 313    * @return object
 314    */
 315         createXhrObject:function(transactionId)
 316         {
 317                 var obj,http,i;
 318                 try
 319                 {
 320                         // Instantiates XMLHttpRequest in non-IE browsers and assigns to http.
 321                         http = new XMLHttpRequest();
 322                         //  Object literal with http and tId properties
 323                         obj = { conn:http, tId:transactionId, xhr: true };
 324                         YAHOO.log('XHR object created for transaction ' + transactionId, 'info', 'Connection');
 325                 }
 326                 catch(e)
 327                 {
 328                         for(i=0; i<this._msxml_progid.length; ++i){
 329                                 try
 330                                 {
 331                                         // Instantiates XMLHttpRequest for IE and assign to http
 332                                         http = new ActiveXObject(this._msxml_progid[i]);
 333                                         //  Object literal with conn and tId properties
 334                                         obj = { conn:http, tId:transactionId, xhr: true };
 335                                         YAHOO.log('ActiveX XHR object created for transaction ' + transactionId, 'info', 'Connection');
 336                                         break;
 337                                 }
 338                                 catch(e1){}
 339                         }
 340                 }
 341                 finally
 342                 {
 343                         return obj;
 344                 }
 345         },
 346
 347   /**
 348    * @description This method is called by asyncRequest to create a
 349    * valid connection object for the transaction.  It also passes a
 350    * transaction id and increments the transaction id counter.
 351    * @method getConnectionObject
 352    * @private
 353    * @static
 354    * @return {object}
 355    */
 356         getConnectionObject:function(t)
 357         {
 358                 var o, tId = this._transaction_id;
 359
 360                 try
 361                 {
 362                         if(!t){
 363                                 o = this.createXhrObject(tId);
 364                         }
 365                         else{
 366                                 o = {tId:tId};
 367                                 if(t==='xdr'){
 368                                         o.conn = this._transport;
 369                                         o.xdr = true;
 370                                 }
 371                                 else if(t==='upload'){
 372                                         o.upload = true;
 373                                 }
 374                         }
 375
 376                         if(o){
 377                                 this._transaction_id++;
 378                         }
 379                 }
 380                 catch(e){}
 381                 return o;
 382         },
 383
 384   /**
 385    * @description Method for initiating an asynchronous request via the XHR object.
 386    * @method asyncRequest
 387    * @public
 388    * @static
 389    * @param {string} method HTTP transaction method
 390    * @param {string} uri Fully qualified path of resource
 391    * @param {callback} callback User-defined callback function or object
 392    * @param {string} postData POST body
 393    * @return {object} Returns the connection object
 394    */
 395         asyncRequest:function(method, uri, callback, postData)
 396         {
 397                 var o,t,args = (callback && callback.argument)?callback.argument:null;
 398
 399                 if(this._isFileUpload){
 400                         t = 'upload';
 401                 }
 402                 else if(callback.xdr){
 403                         t = 'xdr';
 404                 }
 405
 406                 o = this.getConnectionObject(t);
 407                 if(!o){
 408                         YAHOO.log('Unable to create connection object.', 'error', 'Connection');
 409                         return null;
 410                 }
 411                 else{
 412
 413                         // Intialize any transaction-specific custom events, if provided.
 414                         if(callback && callback.customevents){
 415                                 this.initCustomEvents(o, callback);
 416                         }
 417
 418                         if(this._isFormSubmit){
 419                                 if(this._isFileUpload){
 420                                         this.uploadFile(o, callback, uri, postData);
 421                                         return o;
 422                                 }
 423
 424                                 // If the specified HTTP method is GET, setForm() will return an
 425                                 // encoded string that is concatenated to the uri to
 426                                 // create a querystring.
 427                                 if(method.toUpperCase() == 'GET'){
 428                                         if(this._sFormData.length !== 0){
 429                                                 // If the URI already contains a querystring, append an ampersand
 430                                                 // and then concatenate _sFormData to the URI.
 431                                                 uri += ((uri.indexOf('?') == -1)?'?':'&') + this._sFormData;
 432                                         }
 433                                 }
 434                                 else if(method.toUpperCase() == 'POST'){
 435                                         // If POST data exist in addition to the HTML form data,
 436                                         // it will be concatenated to the form data.
 437                                         postData = postData?this._sFormData + "&" + postData:this._sFormData;
 438                                 }
 439                         }
 440
 441                         if(method.toUpperCase() == 'GET' && (callback && callback.cache === false)){
 442                                 // If callback.cache is defined and set to false, a
 443                                 // timestamp value will be added to the querystring.
 444                                 uri += ((uri.indexOf('?') == -1)?'?':'&') + "rnd=" + new Date().valueOf().toString();
 445                         }
 446
 447                         // Each transaction will automatically include a custom header of
 448                         // "X-Requested-With: XMLHttpRequest" to identify the request as
 449                         // having originated from Connection Manager.
 450                         if(this._use_default_xhr_header){
 451                                 if(!this._default_headers['X-Requested-With']){
 452                                         this.initHeader('X-Requested-With', this._default_xhr_header, true);
 453                                         YAHOO.log('Initialize transaction header X-Request-Header to XMLHttpRequest.', 'info', 'Connection');
 454                                 }
 455                         }
 456
 457                         //If the transaction method is POST and the POST header value is set to true
 458                         //or a custom value, initalize the Content-Type header to this value.
 459                         if((method.toUpperCase() === 'POST' && this._use_default_post_header) && this._isFormSubmit === false){
 460                                 this.initHeader('Content-Type', this._default_post_header);
 461                                 YAHOO.log('Initialize header Content-Type to application/x-www-form-urlencoded; UTF-8 for POST transaction.', 'info', 'Connection');
 462                         }
 463
 464                         if(o.xdr){
 465                                 this.xdr(o, method, uri, callback, postData);
 466                                 return o;
 467                         }
 468
 469                         o.conn.open(method, uri, true);
 470                         //Initialize all default and custom HTTP headers,
 471                         if(this._has_default_headers || this._has_http_headers){
 472                                 this.setHeader(o);
 473                         }
 474
 475                         this.handleReadyState(o, callback);
 476                         o.conn.send(postData || '');
 477                         YAHOO.log('Transaction ' + o.tId + ' sent.', 'info', 'Connection');
 478
 479                         // Reset the HTML form data and state properties as
 480                         // soon as the data are submitted.
 481                         if(this._isFormSubmit === true){
 482                                 this.resetFormState();
 483                         }
 484
 485                         // Fire global custom event -- startEvent
 486                         this.startEvent.fire(o, args);
 487
 488                         if(o.startEvent){
 489                                 // Fire transaction custom event -- startEvent
 490                                 o.startEvent.fire(o, args);
 491                         }
 492
 493                         return o;
 494                 }
 495         },
 496
 497   /**
 498    * @description This method creates and subscribes custom events,
 499    * specific to each transaction
 500    * @method initCustomEvents
 501    * @private
 502    * @static
 503    * @param {object} o The connection object
 504    * @param {callback} callback The user-defined callback object
 505    * @return {void}
 506    */
 507         initCustomEvents:function(o, callback)
 508         {
 509                 var prop;
 510                 // Enumerate through callback.customevents members and bind/subscribe
 511                 // events that match in the _customEvents table.
 512                 for(prop in callback.customevents){
 513                         if(this._customEvents[prop][0]){
 514                                 // Create the custom event
 515                                 o[this._customEvents[prop][0]] = new YAHOO.util.CustomEvent(this._customEvents[prop][1], (callback.scope)?callback.scope:null);
 516                                 YAHOO.log('Transaction-specific Custom Event ' + o[this._customEvents[prop][1]] + ' created.', 'info', 'Connection');
 517
 518                                 // Subscribe the custom event
 519                                 o[this._customEvents[prop][0]].subscribe(callback.customevents[prop]);
 520                                 YAHOO.log('Transaction-specific Custom Event ' + o[this._customEvents[prop][1]] + ' subscribed.', 'info', 'Connection');
 521                         }
 522                 }
 523         },
 524
 525   /**
 526    * @description This method serves as a timer that polls the XHR object's readyState
 527    * property during a transaction, instead of binding a callback to the
 528    * onreadystatechange event.  Upon readyState 4, handleTransactionResponse
 529    * will process the response, and the timer will be cleared.
 530    * @method handleReadyState
 531    * @private
 532    * @static
 533    * @param {object} o The connection object
 534    * @param {callback} callback The user-defined callback object
 535    * @return {void}
 536    */
 537
 538     handleReadyState:function(o, callback)
 539
 540     {
 541                 var oConn = this,
 542                         args = (callback && callback.argument)?callback.argument:null;
 543
 544                 if(callback && callback.timeout){
 545                         this._timeOut[o.tId] = window.setTimeout(function(){ oConn.abort(o, callback, true); }, callback.timeout);
 546                 }
 547
 548                 this._poll[o.tId] = window.setInterval(
 549                         function(){
 550                                 if(o.conn && o.conn.readyState === 4){
 551
 552                                         // Clear the polling interval for the transaction
 553                                         // and remove the reference from _poll.
 554                                         window.clearInterval(oConn._poll[o.tId]);
 555                                         delete oConn._poll[o.tId];
 556
 557                                         if(callback && callback.timeout){
 558                                                 window.clearTimeout(oConn._timeOut[o.tId]);
 559                                                 delete oConn._timeOut[o.tId];
 560                                         }
 561
 562                                         // Fire global custom event -- completeEvent
 563                                         oConn.completeEvent.fire(o, args);
 564
 565                                         if(o.completeEvent){
 566                                                 // Fire transaction custom event -- completeEvent
 567                                                 o.completeEvent.fire(o, args);
 568                                         }
 569
 570                                         oConn.handleTransactionResponse(o, callback);
 571                                 }
 572                         }
 573                 ,this._polling_interval);
 574     },
 575
 576   /**
 577    * @description This method attempts to interpret the server response and
 578    * determine whether the transaction was successful, or if an error or
 579    * exception was encountered.
 580    * @method handleTransactionResponse
 581    * @private
 582    * @static
 583    * @param {object} o The connection object
 584    * @param {object} callback The user-defined callback object
 585    * @param {boolean} isAbort Determines if the transaction was terminated via abort().
 586    * @return {void}
 587    */
 588     handleTransactionResponse:function(o, callback, isAbort)
 589     {
 590                 var httpStatus, responseObject,
 591                         args = (callback && callback.argument)?callback.argument:null,
 592                         xdrS = (o.r && o.r.statusText === 'xdr:success')?true:false,
 593                         xdrF = (o.r && o.r.statusText === 'xdr:failure')?true:false,
 594                         xdrA = isAbort;
 595
 596                 try
 597                 {
 598                         if((o.conn.status !== undefined && o.conn.status !== 0) || xdrS){
 599                                 // XDR requests will not have HTTP status defined. The
 600                                 // statusText property will define the response status
 601                                 // set by the Flash transport.
 602                                 httpStatus = o.conn.status;
 603                         }
 604                         else if(xdrF && !xdrA){
 605                                 // Set XDR transaction failure to a status of 0, which
 606                                 // resolves as an HTTP failure, instead of an exception.
 607                                 httpStatus = 0;
 608                         }
 609                         else{
 610                                 httpStatus = 13030;
 611                         }
 612                 }
 613                 catch(e){
 614
 615                          // 13030 is a custom code to indicate the condition -- in Mozilla/FF --
 616                          // when the XHR object's status and statusText properties are
 617                          // unavailable, and a query attempt throws an exception.
 618                         httpStatus = 13030;
 619                 }
 620
 621                 if((httpStatus >= 200 && httpStatus < 300) || httpStatus === 1223 || xdrS){
 622                         responseObject = o.xdr ? o.r : this.createResponseObject(o, args);
 623                         if(callback && callback.success){
 624                                 if(!callback.scope){
 625                                         callback.success(responseObject);
 626                                         YAHOO.log('Success callback. HTTP code is ' + httpStatus, 'info', 'Connection');
 627                                 }
 628                                 else{
 629                                         // If a scope property is defined, the callback will be fired from
 630                                         // the context of the object.
 631                                         callback.success.apply(callback.scope, [responseObject]);
 632                                         YAHOO.log('Success callback with scope. HTTP code is ' + httpStatus, 'info', 'Connection');
 633                                 }
 634                         }
 635
 636                         // Fire global custom event -- successEvent
 637                         this.successEvent.fire(responseObject);
 638
 639                         if(o.successEvent){
 640                                 // Fire transaction custom event -- successEvent
 641                                 o.successEvent.fire(responseObject);
 642                         }
 643                 }
 644                 else{
 645                         switch(httpStatus){
 646                                 // The following cases are wininet.dll error codes that may be encountered.
 647                                 case 12002: // Server timeout
 648                                 case 12029: // 12029 to 12031 correspond to dropped connections.
 649                                 case 12030:
 650                                 case 12031:
 651                                 case 12152: // Connection closed by server.
 652                                 case 13030: // See above comments for variable status.
 653                                         // XDR transactions will not resolve to this case, since the
 654                                         // response object is already built in the xdr response.
 655                                         responseObject = this.createExceptionObject(o.tId, args, (isAbort?isAbort:false));
 656                                         if(callback && callback.failure){
 657                                                 if(!callback.scope){
 658                                                         callback.failure(responseObject);
 659                                                         YAHOO.log('Failure callback. Exception detected. Status code is ' + httpStatus, 'warn', 'Connection');
 660                                                 }
 661                                                 else{
 662                                                         callback.failure.apply(callback.scope, [responseObject]);
 663                                                         YAHOO.log('Failure callback with scope. Exception detected. Status code is ' + httpStatus, 'warn', 'Connection');
 664                                                 }
 665                                         }
 666
 667                                         break;
 668                                 default:
 669                                         responseObject = (o.xdr) ? o.response : this.createResponseObject(o, args);
 670                                         if(callback && callback.failure){
 671                                                 if(!callback.scope){
 672                                                         callback.failure(responseObject);
 673                                                         YAHOO.log('Failure callback. HTTP status code is ' + httpStatus, 'warn', 'Connection');
 674                                                 }
 675                                                 else{
 676                                                         callback.failure.apply(callback.scope, [responseObject]);
 677                                                         YAHOO.log('Failure callback with scope. HTTP status code is ' + httpStatus, 'warn', 'Connection');
 678                                                 }
 679                                         }
 680                         }
 681
 682                         // Fire global custom event -- failureEvent
 683                         this.failureEvent.fire(responseObject);
 684
 685                         if(o.failureEvent){
 686                                 // Fire transaction custom event -- failureEvent
 687                                 o.failureEvent.fire(responseObject);
 688                         }
 689
 690                 }
 691
 692                 this.releaseObject(o);
 693                 responseObject = null;
 694     },
 695
 696   /**
 697    * @description This method evaluates the server response, creates and returns the results via
 698    * its properties.  Success and failure cases will differ in the response
 699    * object's property values.
 700    * @method createResponseObject
 701    * @private
 702    * @static
 703    * @param {object} o The connection object
 704    * @param {callbackArg} callbackArg The user-defined argument or arguments to be passed to the callback
 705    * @return {object}
 706    */
 707     createResponseObject:function(o, callbackArg)
 708     {
 709                 var obj = {}, headerObj = {},
 710                         i, headerStr, header, delimitPos;
 711
 712                 try
 713                 {
 714                         headerStr = o.conn.getAllResponseHeaders();
 715                         header = headerStr.split('\n');
 716                         for(i=0; i<header.length; i++){
 717                                 delimitPos = header[i].indexOf(':');
 718                                 if(delimitPos != -1){
 719                                         headerObj[header[i].substring(0,delimitPos)] = YAHOO.lang.trim(header[i].substring(delimitPos+2));
 720                                 }
 721                         }
 722                 }
 723                 catch(e){}
 724
 725                 obj.tId = o.tId;
 726                 // Normalize IE's response to HTTP 204 when Win error 1223.
 727                 obj.status = (o.conn.status == 1223)?204:o.conn.status;
 728                 // Normalize IE's statusText to "No Content" instead of "Unknown".
 729                 obj.statusText = (o.conn.status == 1223)?"No Content":o.conn.statusText;
 730                 obj.getResponseHeader = headerObj;
 731                 obj.getAllResponseHeaders = headerStr;
 732                 obj.responseText = o.conn.responseText;
 733                 obj.responseXML = o.conn.responseXML;
 734
 735                 if(callbackArg){
 736                         obj.argument = callbackArg;
 737                 }
 738
 739                 return obj;
 740     },
 741
 742   /**
 743    * @description If a transaction cannot be completed due to dropped or closed connections,
 744    * there may be not be enough information to build a full response object.
 745    * The failure callback will be fired and this specific condition can be identified
 746    * by a status property value of 0.
 747    *
 748    * If an abort was successful, the status property will report a value of -1.
 749    *
 750    * @method createExceptionObject
 751    * @private
 752    * @static
 753    * @param {int} tId The Transaction Id
 754    * @param {callbackArg} callbackArg The user-defined argument or arguments to be passed to the callback
 755    * @param {boolean} isAbort Determines if the exception case is caused by a transaction abort
 756    * @return {object}
 757    */
 758     createExceptionObject:function(tId, callbackArg, isAbort)
 759     {
 760                 var COMM_CODE = 0,
 761                         COMM_ERROR = 'communication failure',
 762                         ABORT_CODE = -1,
 763                         ABORT_ERROR = 'transaction aborted',
 764                         obj = {};
 765
 766                 obj.tId = tId;
 767                 if(isAbort){
 768                         obj.status = ABORT_CODE;
 769                         obj.statusText = ABORT_ERROR;
 770                 }
 771                 else{
 772                         obj.status = COMM_CODE;
 773                         obj.statusText = COMM_ERROR;
 774                 }
 775
 776                 if(callbackArg){
 777                         obj.argument = callbackArg;
 778                 }
 779
 780                 return obj;
 781     },
 782
 783   /**
 784    * @description Method that initializes the custom HTTP headers for the each transaction.
 785    * @method initHeader
 786    * @public
 787    * @static
 788    * @param {string} label The HTTP header label
 789    * @param {string} value The HTTP header value
 790    * @param {string} isDefault Determines if the specific header is a default header
 791    * automatically sent with each transaction.
 792    * @return {void}
 793    */
 794         initHeader:function(label, value, isDefault)
 795         {
 796                 var headerObj = (isDefault)?this._default_headers:this._http_headers;
 797
 798                 headerObj[label] = value;
 799                 if(isDefault){
 800                         this._has_default_headers = true;
 801                 }
 802                 else{
 803                         this._has_http_headers = true;
 804                 }
 805         },
 806
 807
 808   /**
 809    * @description Accessor that sets the HTTP headers for each transaction.
 810    * @method setHeader
 811    * @private
 812    * @static
 813    * @param {object} o The connection object for the transaction.
 814    * @return {void}
 815    */
 816         setHeader:function(o)
 817         {
 818                 var prop;
 819                 if(this._has_default_headers){
 820                         for(prop in this._default_headers){
 821                                 if(YAHOO.lang.hasOwnProperty(this._default_headers, prop)){
 822                                         o.conn.setRequestHeader(prop, this._default_headers[prop]);
 823                                         YAHOO.log('Default HTTP header ' + prop + ' set with value of ' + this._default_headers[prop], 'info', 'Connection');
 824                                 }
 825                         }
 826                 }
 827
 828                 if(this._has_http_headers){
 829                         for(prop in this._http_headers){
 830                                 if(YAHOO.lang.hasOwnProperty(this._http_headers, prop)){
 831                                         o.conn.setRequestHeader(prop, this._http_headers[prop]);
 832                                         YAHOO.log('HTTP header ' + prop + ' set with value of ' + this._http_headers[prop], 'info', 'Connection');
 833                                 }
 834                         }
 835
 836                         this._http_headers = {};
 837                         this._has_http_headers = false;
 838                 }
 839         },
 840
 841   /**
 842    * @description Resets the default HTTP headers object
 843    * @method resetDefaultHeaders
 844    * @public
 845    * @static
 846    * @return {void}
 847    */
 848         resetDefaultHeaders:function(){
 849                 this._default_headers = {};
 850                 this._has_default_headers = false;
 851         },
 852
 853   /**
 854    * @description Method to terminate a transaction, if it has not reached readyState 4.
 855    * @method abort
 856    * @public
 857    * @static
 858    * @param {object} o The connection object returned by asyncRequest.
 859    * @param {object} callback  User-defined callback object.
 860    * @param {string} isTimeout boolean to indicate if abort resulted from a callback timeout.
 861    * @return {boolean}
 862    */
 863         abort:function(o, callback, isTimeout)
 864         {
 865                 var abortStatus,
 866                         args = (callback && callback.argument)?callback.argument:null;
 867                         o = o || {};
 868
 869                 if(o.conn){
 870                         if(o.xhr){
 871                                 if(this.isCallInProgress(o)){
 872                                         // Issue abort request
 873                                         o.conn.abort();
 874
 875                                         window.clearInterval(this._poll[o.tId]);
 876                                         delete this._poll[o.tId];
 877
 878                                         if(isTimeout){
 879                                                 window.clearTimeout(this._timeOut[o.tId]);
 880                                                 delete this._timeOut[o.tId];
 881                                         }
 882
 883                                         abortStatus = true;
 884                                 }
 885                         }
 886                         else if(o.xdr){
 887                                 o.conn.abort(o.tId);
 888                                 abortStatus = true;
 889                         }
 890                 }
 891                 else if(o.upload){
 892                         var frameId = 'yuiIO' + o.tId;
 893                         var io = document.getElementById(frameId);
 894
 895                         if(io){
 896                                 // Remove all listeners on the iframe prior to
 897                                 // its destruction.
 898                                 YAHOO.util.Event.removeListener(io, "load");
 899                                 // Destroy the iframe facilitating the transaction.
 900                                 document.body.removeChild(io);
 901                                 YAHOO.log('File upload iframe destroyed. Id is:' + frameId, 'info', 'Connection');
 902
 903                                 if(isTimeout){
 904                                         window.clearTimeout(this._timeOut[o.tId]);
 905                                         delete this._timeOut[o.tId];
 906                                 }
 907
 908                                 abortStatus = true;
 909                         }
 910                 }
 911                 else{
 912                         abortStatus = false;
 913                 }
 914
 915                 if(abortStatus === true){
 916                         // Fire global custom event -- abortEvent
 917                         this.abortEvent.fire(o, args);
 918
 919                         if(o.abortEvent){
 920                                 // Fire transaction custom event -- abortEvent
 921                                 o.abortEvent.fire(o, args);
 922                         }
 923
 924                         this.handleTransactionResponse(o, callback, true);
 925                         YAHOO.log('Transaction ' + o.tId + ' aborted.', 'info', 'Connection');
 926                 }
 927
 928                 return abortStatus;
 929         },
 930
 931   /**
 932    * @description Determines if the transaction is still being processed.
 933    * @method isCallInProgress
 934    * @public
 935    * @static
 936    * @param {object} o The connection object returned by asyncRequest
 937    * @return {boolean}
 938    */
 939         isCallInProgress:function(o)
 940         {
 941                 o = o || {};
 942                 // if the XHR object assigned to the transaction has not been dereferenced,
 943                 // then check its readyState status.  Otherwise, return false.
 944                 if(o.xhr && o.conn){
 945                         return o.conn.readyState !== 4 && o.conn.readyState !== 0;
 946                 }
 947                 else if(o.xdr && o.conn){
 948                         return o.conn.isCallInProgress(o.tId);
 949                 }
 950                 else if(o.upload === true){
 951                         return document.getElementById('yuiIO' + o.tId)?true:false;
 952                 }
 953                 else{
 954                         return false;
 955                 }
 956         },
 957
 958   /**
 959    * @description Dereference the XHR instance and the connection object after the transaction is completed.
 960    * @method releaseObject
 961    * @private
 962    * @static
 963    * @param {object} o The connection object
 964    * @return {void}
 965    */
 966         releaseObject:function(o)
 967         {
 968                 if(o && o.conn){
 969                         //dereference the XHR instance.
 970                         o.conn = null;
 971
 972                         YAHOO.log('Connection object for transaction ' + o.tId + ' destroyed.', 'info', 'Connection');
 973
 974                         //dereference the connection object.
 975                         o = null;
 976                 }
 977         }
 978 };
 979
 980 YAHOO.register("connection_core", YAHOO.util.Connect, {version: "2.8.0r4", build: "2449"});