wradmin/static/yui/connection/connection.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: 2.7.0
   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 Property modified by setForm() to determine if the data
 135   * should be submitted as an HTML form.
 136   * @property _isFormSubmit
 137   * @private
 138   * @static
 139   * @type boolean
 140   */
 141     _isFormSubmit:false,
 142
 143  /**
 144   * @description Property modified by setForm() to determine if a file(s)
 145   * upload is expected.
 146   * @property _isFileUpload
 147   * @private
 148   * @static
 149   * @type boolean
 150   */
 151     _isFileUpload:false,
 152
 153  /**
 154   * @description Property modified by setForm() to set a reference to the HTML
 155   * form node if the desired action is file upload.
 156   * @property _formNode
 157   * @private
 158   * @static
 159   * @type object
 160   */
 161     _formNode:null,
 162
 163  /**
 164   * @description Property modified by setForm() to set the HTML form data
 165   * for each transaction.
 166   * @property _sFormData
 167   * @private
 168   * @static
 169   * @type string
 170   */
 171     _sFormData:null,
 172
 173  /**
 174   * @description Collection of polling references to the polling mechanism in handleReadyState.
 175   * @property _poll
 176   * @private
 177   * @static
 178   * @type object
 179   */
 180     _poll:{},
 181
 182  /**
 183   * @description Queue of timeout values for each transaction callback with a defined timeout value.
 184   * @property _timeOut
 185   * @private
 186   * @static
 187   * @type object
 188   */
 189     _timeOut:{},
 190
 191   /**
 192    * @description The polling frequency, in milliseconds, for HandleReadyState.
 193    * when attempting to determine a transaction's XHR readyState.
 194    * The default is 50 milliseconds.
 195    * @property _polling_interval
 196    * @private
 197    * @static
 198    * @type int
 199    */
 200      _polling_interval:50,
 201
 202   /**
 203    * @description A transaction counter that increments the transaction id for each transaction.
 204    * @property _transaction_id
 205    * @private
 206    * @static
 207    * @type int
 208    */
 209      _transaction_id:0,
 210
 211   /**
 212    * @description Tracks the name-value pair of the "clicked" submit button if multiple submit
 213    * buttons are present in an HTML form; and, if YAHOO.util.Event is available.
 214    * @property _submitElementValue
 215    * @private
 216    * @static
 217    * @type string
 218    */
 219          _submitElementValue:null,
 220
 221   /**
 222    * @description Determines whether YAHOO.util.Event is available and returns true or false.
 223    * If true, an event listener is bound at the document level to trap click events that
 224    * resolve to a target type of "Submit".  This listener will enable setForm() to determine
 225    * the clicked "Submit" value in a multi-Submit button, HTML form.
 226    * @property _hasSubmitListener
 227    * @private
 228    * @static
 229    */
 230          _hasSubmitListener:(function()
 231          {
 232                 if(YAHOO.util.Event){
 233                         YAHOO.util.Event.addListener(
 234                                 document,
 235                                 'click',
 236                                 function(e){
 237                                         var obj = YAHOO.util.Event.getTarget(e),
 238                                                 name = obj.nodeName.toLowerCase();
 239                                         if((name === 'input' || name === 'button') && (obj.type && obj.type.toLowerCase() == 'submit')){
 240                                                 YAHOO.util.Connect._submitElementValue = encodeURIComponent(obj.name) + "=" + encodeURIComponent(obj.value);
 241                                         }
 242                                 });
 243                         return true;
 244             }
 245             return false;
 246          })(),
 247
 248   /**
 249    * @description Custom event that fires at the start of a transaction
 250    * @property startEvent
 251    * @private
 252    * @static
 253    * @type CustomEvent
 254    */
 255         startEvent: new YAHOO.util.CustomEvent('start'),
 256
 257   /**
 258    * @description Custom event that fires when a transaction response has completed.
 259    * @property completeEvent
 260    * @private
 261    * @static
 262    * @type CustomEvent
 263    */
 264         completeEvent: new YAHOO.util.CustomEvent('complete'),
 265
 266   /**
 267    * @description Custom event that fires when handleTransactionResponse() determines a
 268    * response in the HTTP 2xx range.
 269    * @property successEvent
 270    * @private
 271    * @static
 272    * @type CustomEvent
 273    */
 274         successEvent: new YAHOO.util.CustomEvent('success'),
 275
 276   /**
 277    * @description Custom event that fires when handleTransactionResponse() determines a
 278    * response in the HTTP 4xx/5xx range.
 279    * @property failureEvent
 280    * @private
 281    * @static
 282    * @type CustomEvent
 283    */
 284         failureEvent: new YAHOO.util.CustomEvent('failure'),
 285
 286   /**
 287    * @description Custom event that fires when handleTransactionResponse() determines a
 288    * response in the HTTP 4xx/5xx range.
 289    * @property failureEvent
 290    * @private
 291    * @static
 292    * @type CustomEvent
 293    */
 294         uploadEvent: new YAHOO.util.CustomEvent('upload'),
 295
 296   /**
 297    * @description Custom event that fires when a transaction is successfully aborted.
 298    * @property abortEvent
 299    * @private
 300    * @static
 301    * @type CustomEvent
 302    */
 303         abortEvent: new YAHOO.util.CustomEvent('abort'),
 304
 305   /**
 306    * @description A reference table that maps callback custom events members to its specific
 307    * event name.
 308    * @property _customEvents
 309    * @private
 310    * @static
 311    * @type object
 312    */
 313         _customEvents:
 314         {
 315                 onStart:['startEvent', 'start'],
 316                 onComplete:['completeEvent', 'complete'],
 317                 onSuccess:['successEvent', 'success'],
 318                 onFailure:['failureEvent', 'failure'],
 319                 onUpload:['uploadEvent', 'upload'],
 320                 onAbort:['abortEvent', 'abort']
 321         },
 322
 323   /**
 324    * @description Member to add an ActiveX id to the existing xml_progid array.
 325    * In the event(unlikely) a new ActiveX id is introduced, it can be added
 326    * without internal code modifications.
 327    * @method setProgId
 328    * @public
 329    * @static
 330    * @param {string} id The ActiveX id to be added to initialize the XHR object.
 331    * @return void
 332    */
 333         setProgId:function(id)
 334         {
 335                 this._msxml_progid.unshift(id);
 336         },
 337
 338   /**
 339    * @description Member to override the default POST header.
 340    * @method setDefaultPostHeader
 341    * @public
 342    * @static
 343    * @param {boolean} b Set and use default header - true or false .
 344    * @return void
 345    */
 346         setDefaultPostHeader:function(b)
 347         {
 348                 if(typeof b == 'string'){
 349                         this._default_post_header = b;
 350                 }
 351                 else if(typeof b == 'boolean'){
 352                         this._use_default_post_header = b;
 353                 }
 354         },
 355
 356   /**
 357    * @description Member to override the default transaction header..
 358    * @method setDefaultXhrHeader
 359    * @public
 360    * @static
 361    * @param {boolean} b Set and use default header - true or false .
 362    * @return void
 363    */
 364         setDefaultXhrHeader:function(b)
 365         {
 366                 if(typeof b == 'string'){
 367                         this._default_xhr_header = b;
 368                 }
 369                 else{
 370                         this._use_default_xhr_header = b;
 371                 }
 372         },
 373
 374   /**
 375    * @description Member to modify the default polling interval.
 376    * @method setPollingInterval
 377    * @public
 378    * @static
 379    * @param {int} i The polling interval in milliseconds.
 380    * @return void
 381    */
 382         setPollingInterval:function(i)
 383         {
 384                 if(typeof i == 'number' && isFinite(i)){
 385                         this._polling_interval = i;
 386                 }
 387         },
 388
 389   /**
 390    * @description Instantiates a XMLHttpRequest object and returns an object with two properties:
 391    * the XMLHttpRequest instance and the transaction id.
 392    * @method createXhrObject
 393    * @private
 394    * @static
 395    * @param {int} transactionId Property containing the transaction id for this transaction.
 396    * @return object
 397    */
 398         createXhrObject:function(transactionId)
 399         {
 400                 var obj,http;
 401                 try
 402                 {
 403                         // Instantiates XMLHttpRequest in non-IE browsers and assigns to http.
 404                         http = new XMLHttpRequest();
 405                         //  Object literal with http and tId properties
 406                         obj = { conn:http, tId:transactionId };
 407                 }
 408                 catch(e)
 409                 {
 410                         for(var i=0; i<this._msxml_progid.length; ++i){
 411                                 try
 412                                 {
 413                                         // Instantiates XMLHttpRequest for IE and assign to http
 414                                         http = new ActiveXObject(this._msxml_progid[i]);
 415                                         //  Object literal with conn and tId properties
 416                                         obj = { conn:http, tId:transactionId };
 417                                         break;
 418                                 }
 419                                 catch(e2){}
 420                         }
 421                 }
 422                 finally
 423                 {
 424                         return obj;
 425                 }
 426         },
 427
 428   /**
 429    * @description This method is called by asyncRequest to create a
 430    * valid connection object for the transaction.  It also passes a
 431    * transaction id and increments the transaction id counter.
 432    * @method getConnectionObject
 433    * @private
 434    * @static
 435    * @return {object}
 436    */
 437         getConnectionObject:function(isFileUpload)
 438         {
 439                 var o;
 440                 var tId = this._transaction_id;
 441
 442                 try
 443                 {
 444                         if(!isFileUpload){
 445                                 o = this.createXhrObject(tId);
 446                         }
 447                         else{
 448                                 o = {};
 449                                 o.tId = tId;
 450                                 o.isUpload = true;
 451                         }
 452
 453                         if(o){
 454                                 this._transaction_id++;
 455                         }
 456                 }
 457                 catch(e){}
 458                 finally
 459                 {
 460                         return o;
 461                 }
 462         },
 463
 464   /**
 465    * @description Method for initiating an asynchronous request via the XHR object.
 466    * @method asyncRequest
 467    * @public
 468    * @static
 469    * @param {string} method HTTP transaction method
 470    * @param {string} uri Fully qualified path of resource
 471    * @param {callback} callback User-defined callback function or object
 472    * @param {string} postData POST body
 473    * @return {object} Returns the connection object
 474    */
 475         asyncRequest:function(method, uri, callback, postData)
 476         {
 477                 var o = (this._isFileUpload)?this.getConnectionObject(true):this.getConnectionObject();
 478                 var args = (callback && callback.argument)?callback.argument:null;
 479
 480                 if(!o){
 481                         return null;
 482                 }
 483                 else{
 484
 485                         // Intialize any transaction-specific custom events, if provided.
 486                         if(callback && callback.customevents){
 487                                 this.initCustomEvents(o, callback);
 488                         }
 489
 490                         if(this._isFormSubmit){
 491                                 if(this._isFileUpload){
 492                                         this.uploadFile(o, callback, uri, postData);
 493                                         return o;
 494                                 }
 495
 496                                 // If the specified HTTP method is GET, setForm() will return an
 497                                 // encoded string that is concatenated to the uri to
 498                                 // create a querystring.
 499                                 if(method.toUpperCase() == 'GET'){
 500                                         if(this._sFormData.length !== 0){
 501                                                 // If the URI already contains a querystring, append an ampersand
 502                                                 // and then concatenate _sFormData to the URI.
 503                                                 uri += ((uri.indexOf('?') == -1)?'?':'&') + this._sFormData;
 504                                         }
 505                                 }
 506                                 else if(method.toUpperCase() == 'POST'){
 507                                         // If POST data exist in addition to the HTML form data,
 508                                         // it will be concatenated to the form data.
 509                                         postData = postData?this._sFormData + "&" + postData:this._sFormData;
 510                                 }
 511                         }
 512
 513                         if(method.toUpperCase() == 'GET' && (callback && callback.cache === false)){
 514                                 // If callback.cache is defined and set to false, a
 515                                 // timestamp value will be added to the querystring.
 516                                 uri += ((uri.indexOf('?') == -1)?'?':'&') + "rnd=" + new Date().valueOf().toString();
 517                         }
 518
 519                         o.conn.open(method, uri, true);
 520
 521                         // Each transaction will automatically include a custom header of
 522                         // "X-Requested-With: XMLHttpRequest" to identify the request as
 523                         // having originated from Connection Manager.
 524                         if(this._use_default_xhr_header){
 525                                 if(!this._default_headers['X-Requested-With']){
 526                                         this.initHeader('X-Requested-With', this._default_xhr_header, true);
 527                                 }
 528                         }
 529
 530                         //If the transaction method is POST and the POST header value is set to true
 531                         //or a custom value, initalize the Content-Type header to this value.
 532                         if((method.toUpperCase() === 'POST' && this._use_default_post_header) && this._isFormSubmit === false){
 533                                 this.initHeader('Content-Type', this._default_post_header);
 534                         }
 535
 536                         //Initialize all default and custom HTTP headers,
 537                         if(this._has_default_headers || this._has_http_headers){
 538                                 this.setHeader(o);
 539                         }
 540
 541                         this.handleReadyState(o, callback);
 542                         o.conn.send(postData || '');
 543
 544
 545                         // Reset the HTML form data and state properties as
 546                         // soon as the data are submitted.
 547                         if(this._isFormSubmit === true){
 548                                 this.resetFormState();
 549                         }
 550
 551                         // Fire global custom event -- startEvent
 552                         this.startEvent.fire(o, args);
 553
 554                         if(o.startEvent){
 555                                 // Fire transaction custom event -- startEvent
 556                                 o.startEvent.fire(o, args);
 557                         }
 558
 559                         return o;
 560                 }
 561         },
 562
 563   /**
 564    * @description This method creates and subscribes custom events,
 565    * specific to each transaction
 566    * @method initCustomEvents
 567    * @private
 568    * @static
 569    * @param {object} o The connection object
 570    * @param {callback} callback The user-defined callback object
 571    * @return {void}
 572    */
 573         initCustomEvents:function(o, callback)
 574         {
 575                 var prop;
 576                 // Enumerate through callback.customevents members and bind/subscribe
 577                 // events that match in the _customEvents table.
 578                 for(prop in callback.customevents){
 579                         if(this._customEvents[prop][0]){
 580                                 // Create the custom event
 581                                 o[this._customEvents[prop][0]] = new YAHOO.util.CustomEvent(this._customEvents[prop][1], (callback.scope)?callback.scope:null);
 582
 583                                 // Subscribe the custom event
 584                                 o[this._customEvents[prop][0]].subscribe(callback.customevents[prop]);
 585                         }
 586                 }
 587         },
 588
 589   /**
 590    * @description This method serves as a timer that polls the XHR object's readyState
 591    * property during a transaction, instead of binding a callback to the
 592    * onreadystatechange event.  Upon readyState 4, handleTransactionResponse
 593    * will process the response, and the timer will be cleared.
 594    * @method handleReadyState
 595    * @private
 596    * @static
 597    * @param {object} o The connection object
 598    * @param {callback} callback The user-defined callback object
 599    * @return {void}
 600    */
 601
 602     handleReadyState:function(o, callback)
 603
 604     {
 605                 var oConn = this;
 606                 var args = (callback && callback.argument)?callback.argument:null;
 607
 608                 if(callback && callback.timeout){
 609                         this._timeOut[o.tId] = window.setTimeout(function(){ oConn.abort(o, callback, true); }, callback.timeout);
 610                 }
 611
 612                 this._poll[o.tId] = window.setInterval(
 613                         function(){
 614                                 if(o.conn && o.conn.readyState === 4){
 615
 616                                         // Clear the polling interval for the transaction
 617                                         // and remove the reference from _poll.
 618                                         window.clearInterval(oConn._poll[o.tId]);
 619                                         delete oConn._poll[o.tId];
 620
 621                                         if(callback && callback.timeout){
 622                                                 window.clearTimeout(oConn._timeOut[o.tId]);
 623                                                 delete oConn._timeOut[o.tId];
 624                                         }
 625
 626                                         // Fire global custom event -- completeEvent
 627                                         oConn.completeEvent.fire(o, args);
 628
 629                                         if(o.completeEvent){
 630                                                 // Fire transaction custom event -- completeEvent
 631                                                 o.completeEvent.fire(o, args);
 632                                         }
 633
 634                                         oConn.handleTransactionResponse(o, callback);
 635                                 }
 636                         }
 637                 ,this._polling_interval);
 638     },
 639
 640   /**
 641    * @description This method attempts to interpret the server response and
 642    * determine whether the transaction was successful, or if an error or
 643    * exception was encountered.
 644    * @method handleTransactionResponse
 645    * @private
 646    * @static
 647    * @param {object} o The connection object
 648    * @param {object} callback The user-defined callback object
 649    * @param {boolean} isAbort Determines if the transaction was terminated via abort().
 650    * @return {void}
 651    */
 652     handleTransactionResponse:function(o, callback, isAbort)
 653     {
 654                 var httpStatus, responseObject;
 655                 var args = (callback && callback.argument)?callback.argument:null;
 656
 657                 try
 658                 {
 659                         if(o.conn.status !== undefined && o.conn.status !== 0){
 660                                 httpStatus = o.conn.status;
 661                         }
 662                         else{
 663                                 httpStatus = 13030;
 664                         }
 665                 }
 666                 catch(e){
 667
 668                          // 13030 is a custom code to indicate the condition -- in Mozilla/FF --
 669                          // when the XHR object's status and statusText properties are
 670                          // unavailable, and a query attempt throws an exception.
 671                         httpStatus = 13030;
 672                 }
 673
 674                 if(httpStatus >= 200 && httpStatus < 300 || httpStatus === 1223){
 675                         responseObject = this.createResponseObject(o, args);
 676                         if(callback && callback.success){
 677                                 if(!callback.scope){
 678                                         callback.success(responseObject);
 679                                 }
 680                                 else{
 681                                         // If a scope property is defined, the callback will be fired from
 682                                         // the context of the object.
 683                                         callback.success.apply(callback.scope, [responseObject]);
 684                                 }
 685                         }
 686
 687                         // Fire global custom event -- successEvent
 688                         this.successEvent.fire(responseObject);
 689
 690                         if(o.successEvent){
 691                                 // Fire transaction custom event -- successEvent
 692                                 o.successEvent.fire(responseObject);
 693                         }
 694                 }
 695                 else{
 696                         switch(httpStatus){
 697                                 // The following cases are wininet.dll error codes that may be encountered.
 698                                 case 12002: // Server timeout
 699                                 case 12029: // 12029 to 12031 correspond to dropped connections.
 700                                 case 12030:
 701                                 case 12031:
 702                                 case 12152: // Connection closed by server.
 703                                 case 13030: // See above comments for variable status.
 704                                         responseObject = this.createExceptionObject(o.tId, args, (isAbort?isAbort:false));
 705                                         if(callback && callback.failure){
 706                                                 if(!callback.scope){
 707                                                         callback.failure(responseObject);
 708                                                 }
 709                                                 else{
 710                                                         callback.failure.apply(callback.scope, [responseObject]);
 711                                                 }
 712                                         }
 713
 714                                         break;
 715                                 default:
 716                                         responseObject = this.createResponseObject(o, args);
 717                                         if(callback && callback.failure){
 718                                                 if(!callback.scope){
 719                                                         callback.failure(responseObject);
 720                                                 }
 721                                                 else{
 722                                                         callback.failure.apply(callback.scope, [responseObject]);
 723                                                 }
 724                                         }
 725                         }
 726
 727                         // Fire global custom event -- failureEvent
 728                         this.failureEvent.fire(responseObject);
 729
 730                         if(o.failureEvent){
 731                                 // Fire transaction custom event -- failureEvent
 732                                 o.failureEvent.fire(responseObject);
 733                         }
 734
 735                 }
 736
 737                 this.releaseObject(o);
 738                 responseObject = null;
 739     },
 740
 741   /**
 742    * @description This method evaluates the server response, creates and returns the results via
 743    * its properties.  Success and failure cases will differ in the response
 744    * object's property values.
 745    * @method createResponseObject
 746    * @private
 747    * @static
 748    * @param {object} o The connection object
 749    * @param {callbackArg} callbackArg The user-defined argument or arguments to be passed to the callback
 750    * @return {object}
 751    */
 752     createResponseObject:function(o, callbackArg)
 753     {
 754                 var obj = {};
 755                 var headerObj = {};
 756
 757                 try
 758                 {
 759                         var headerStr = o.conn.getAllResponseHeaders();
 760                         var header = headerStr.split('\n');
 761                         for(var i=0; i<header.length; i++){
 762                                 var delimitPos = header[i].indexOf(':');
 763                                 if(delimitPos != -1){
 764                                         headerObj[header[i].substring(0,delimitPos)] = header[i].substring(delimitPos+2);
 765                                 }
 766                         }
 767                 }
 768                 catch(e){}
 769
 770                 obj.tId = o.tId;
 771                 // Normalize IE's response to HTTP 204 when Win error 1223.
 772                 obj.status = (o.conn.status == 1223)?204:o.conn.status;
 773                 // Normalize IE's statusText to "No Content" instead of "Unknown".
 774                 obj.statusText = (o.conn.status == 1223)?"No Content":o.conn.statusText;
 775                 obj.getResponseHeader = headerObj;
 776                 obj.getAllResponseHeaders = headerStr;
 777                 obj.responseText = o.conn.responseText;
 778                 obj.responseXML = o.conn.responseXML;
 779
 780                 if(callbackArg){
 781                         obj.argument = callbackArg;
 782                 }
 783
 784                 return obj;
 785     },
 786
 787   /**
 788    * @description If a transaction cannot be completed due to dropped or closed connections,
 789    * there may be not be enough information to build a full response object.
 790    * The failure callback will be fired and this specific condition can be identified
 791    * by a status property value of 0.
 792    *
 793    * If an abort was successful, the status property will report a value of -1.
 794    *
 795    * @method createExceptionObject
 796    * @private
 797    * @static
 798    * @param {int} tId The Transaction Id
 799    * @param {callbackArg} callbackArg The user-defined argument or arguments to be passed to the callback
 800    * @param {boolean} isAbort Determines if the exception case is caused by a transaction abort
 801    * @return {object}
 802    */
 803     createExceptionObject:function(tId, callbackArg, isAbort)
 804     {
 805                 var COMM_CODE = 0;
 806                 var COMM_ERROR = 'communication failure';
 807                 var ABORT_CODE = -1;
 808                 var ABORT_ERROR = 'transaction aborted';
 809
 810                 var obj = {};
 811
 812                 obj.tId = tId;
 813                 if(isAbort){
 814                         obj.status = ABORT_CODE;
 815                         obj.statusText = ABORT_ERROR;
 816                 }
 817                 else{
 818                         obj.status = COMM_CODE;
 819                         obj.statusText = COMM_ERROR;
 820                 }
 821
 822                 if(callbackArg){
 823                         obj.argument = callbackArg;
 824                 }
 825
 826                 return obj;
 827     },
 828
 829   /**
 830    * @description Method that initializes the custom HTTP headers for the each transaction.
 831    * @method initHeader
 832    * @public
 833    * @static
 834    * @param {string} label The HTTP header label
 835    * @param {string} value The HTTP header value
 836    * @param {string} isDefault Determines if the specific header is a default header
 837    * automatically sent with each transaction.
 838    * @return {void}
 839    */
 840         initHeader:function(label, value, isDefault)
 841         {
 842                 var headerObj = (isDefault)?this._default_headers:this._http_headers;
 843                 headerObj[label] = value;
 844
 845                 if(isDefault){
 846                         this._has_default_headers = true;
 847                 }
 848                 else{
 849                         this._has_http_headers = true;
 850                 }
 851         },
 852
 853
 854   /**
 855    * @description Accessor that sets the HTTP headers for each transaction.
 856    * @method setHeader
 857    * @private
 858    * @static
 859    * @param {object} o The connection object for the transaction.
 860    * @return {void}
 861    */
 862         setHeader:function(o)
 863         {
 864                 var prop;
 865                 if(this._has_default_headers){
 866                         for(prop in this._default_headers){
 867                                 if(YAHOO.lang.hasOwnProperty(this._default_headers, prop)){
 868                                         o.conn.setRequestHeader(prop, this._default_headers[prop]);
 869                                 }
 870                         }
 871                 }
 872
 873                 if(this._has_http_headers){
 874                         for(prop in this._http_headers){
 875                                 if(YAHOO.lang.hasOwnProperty(this._http_headers, prop)){
 876                                         o.conn.setRequestHeader(prop, this._http_headers[prop]);
 877                                 }
 878                         }
 879                         delete this._http_headers;
 880
 881                         this._http_headers = {};
 882                         this._has_http_headers = false;
 883                 }
 884         },
 885
 886   /**
 887    * @description Resets the default HTTP headers object
 888    * @method resetDefaultHeaders
 889    * @public
 890    * @static
 891    * @return {void}
 892    */
 893         resetDefaultHeaders:function(){
 894                 delete this._default_headers;
 895                 this._default_headers = {};
 896                 this._has_default_headers = false;
 897         },
 898
 899   /**
 900    * @description This method assembles the form label and value pairs and
 901    * constructs an encoded string.
 902    * asyncRequest() will automatically initialize the transaction with a
 903    * a HTTP header Content-Type of application/x-www-form-urlencoded.
 904    * @method setForm
 905    * @public
 906    * @static
 907    * @param {string || object} form id or name attribute, or form object.
 908    * @param {boolean} optional enable file upload.
 909    * @param {boolean} optional enable file upload over SSL in IE only.
 910    * @return {string} string of the HTML form field name and value pairs..
 911    */
 912         setForm:function(formId, isUpload, secureUri)
 913         {
 914         var oForm, oElement, oName, oValue, oDisabled,
 915             hasSubmit = false,
 916             data = [], item = 0,
 917             i,len,j,jlen,opt;
 918
 919                 this.resetFormState();
 920
 921                 if(typeof formId == 'string'){
 922                         // Determine if the argument is a form id or a form name.
 923                         // Note form name usage is deprecated by supported
 924                         // here for legacy reasons.
 925                         oForm = (document.getElementById(formId) || document.forms[formId]);
 926                 }
 927                 else if(typeof formId == 'object'){
 928                         // Treat argument as an HTML form object.
 929                         oForm = formId;
 930                 }
 931                 else{
 932                         return;
 933                 }
 934
 935                 // If the isUpload argument is true, setForm will call createFrame to initialize
 936                 // an iframe as the form target.
 937                 //
 938                 // The argument secureURI is also required by IE in SSL environments
 939                 // where the secureURI string is a fully qualified HTTP path, used to set the source
 940                 // of the iframe, to a stub resource in the same domain.
 941                 if(isUpload){
 942
 943                         // Create iframe in preparation for file upload.
 944                         this.createFrame(secureUri?secureUri:null);
 945
 946                         // Set form reference and file upload properties to true.
 947                         this._isFormSubmit = true;
 948                         this._isFileUpload = true;
 949                         this._formNode = oForm;
 950
 951                         return;
 952
 953                 }
 954
 955                 // Iterate over the form elements collection to construct the
 956                 // label-value pairs.
 957                 for (i=0,len=oForm.elements.length; i<len; ++i){
 958                         oElement  = oForm.elements[i];
 959                         oDisabled = oElement.disabled;
 960             oName     = oElement.name;
 961
 962                         // Do not submit fields that are disabled or
 963                         // do not have a name attribute value.
 964                         if(!oDisabled && oName)
 965                         {
 966                 oName  = encodeURIComponent(oName)+'=';
 967                 oValue = encodeURIComponent(oElement.value);
 968
 969                                 switch(oElement.type)
 970                                 {
 971                     // Safari, Opera, FF all default opt.value from .text if
 972                     // value attribute not specified in markup
 973                                         case 'select-one':
 974                         if (oElement.selectedIndex > -1) {
 975                             opt = oElement.options[oElement.selectedIndex];
 976                             data[item++] = oName + encodeURIComponent(
 977                                 (opt.attributes.value && opt.attributes.value.specified) ? opt.value : opt.text);
 978                         }
 979                         break;
 980                                         case 'select-multiple':
 981                         if (oElement.selectedIndex > -1) {
 982                             for(j=oElement.selectedIndex, jlen=oElement.options.length; j<jlen; ++j){
 983                                 opt = oElement.options[j];
 984                                 if (opt.selected) {
 985                                     data[item++] = oName + encodeURIComponent(
 986                                         (opt.attributes.value && opt.attributes.value.specified) ? opt.value : opt.text);
 987                                 }
 988                             }
 989                         }
 990                                                 break;
 991                                         case 'radio':
 992                                         case 'checkbox':
 993                                                 if(oElement.checked){
 994                             data[item++] = oName + oValue;
 995                                                 }
 996                                                 break;
 997                                         case 'file':
 998                                                 // stub case as XMLHttpRequest will only send the file path as a string.
 999                                         case undefined:
1000                                                 // stub case for fieldset element which returns undefined.
1001                                         case 'reset':
1002                                                 // stub case for input type reset button.
1003                                         case 'button':
1004                                                 // stub case for input type button elements.
1005                                                 break;
1006                                         case 'submit':
1007                                                 if(hasSubmit === false){
1008                                                         if(this._hasSubmitListener && this._submitElementValue){
1009                                 data[item++] = this._submitElementValue;
1010                                                         }
1011                                                         hasSubmit = true;
1012                                                 }
1013                                                 break;
1014                                         default:
1015                         data[item++] = oName + oValue;
1016                                 }
1017                         }
1018                 }
1019
1020                 this._isFormSubmit = true;
1021                 this._sFormData = data.join('&');
1022
1023
1024                 this.initHeader('Content-Type', this._default_form_header);
1025
1026                 return this._sFormData;
1027         },
1028
1029   /**
1030    * @description Resets HTML form properties when an HTML form or HTML form
1031    * with file upload transaction is sent.
1032    * @method resetFormState
1033    * @private
1034    * @static
1035    * @return {void}
1036    */
1037         resetFormState:function(){
1038                 this._isFormSubmit = false;
1039                 this._isFileUpload = false;
1040                 this._formNode = null;
1041                 this._sFormData = "";
1042         },
1043
1044   /**
1045    * @description Creates an iframe to be used for form file uploads.  It is remove from the
1046    * document upon completion of the upload transaction.
1047    * @method createFrame
1048    * @private
1049    * @static
1050    * @param {string} optional qualified path of iframe resource for SSL in IE.
1051    * @return {void}
1052    */
1053         createFrame:function(secureUri){
1054
1055                 // IE does not allow the setting of id and name attributes as object
1056                 // properties via createElement().  A different iframe creation
1057                 // pattern is required for IE.
1058                 var frameId = 'yuiIO' + this._transaction_id;
1059                 var io;
1060                 if(YAHOO.env.ua.ie){
1061                         io = document.createElement('<iframe id="' + frameId + '" name="' + frameId + '" />');
1062
1063                         // IE will throw a security exception in an SSL environment if the
1064                         // iframe source is undefined.
1065                         if(typeof secureUri == 'boolean'){
1066                                 io.src = 'javascript:false';
1067                         }
1068                 }
1069                 else{
1070                         io = document.createElement('iframe');
1071                         io.id = frameId;
1072                         io.name = frameId;
1073                 }
1074
1075                 io.style.position = 'absolute';
1076                 io.style.top = '-1000px';
1077                 io.style.left = '-1000px';
1078
1079                 document.body.appendChild(io);
1080         },
1081
1082   /**
1083    * @description Parses the POST data and creates hidden form elements
1084    * for each key-value, and appends them to the HTML form object.
1085    * @method appendPostData
1086    * @private
1087    * @static
1088    * @param {string} postData The HTTP POST data
1089    * @return {array} formElements Collection of hidden fields.
1090    */
1091         appendPostData:function(postData)
1092         {
1093                 var formElements = [],
1094                         postMessage = postData.split('&'),
1095                         i, delimitPos;
1096                 for(i=0; i < postMessage.length; i++){
1097                         delimitPos = postMessage[i].indexOf('=');
1098                         if(delimitPos != -1){
1099                                 formElements[i] = document.createElement('input');
1100                                 formElements[i].type = 'hidden';
1101                                 formElements[i].name = decodeURIComponent(postMessage[i].substring(0,delimitPos));
1102                                 formElements[i].value = decodeURIComponent(postMessage[i].substring(delimitPos+1));
1103                                 this._formNode.appendChild(formElements[i]);
1104                         }
1105                 }
1106
1107                 return formElements;
1108         },
1109
1110   /**
1111    * @description Uploads HTML form, inclusive of files/attachments, using the
1112    * iframe created in createFrame to facilitate the transaction.
1113    * @method uploadFile
1114    * @private
1115    * @static
1116    * @param {int} id The transaction id.
1117    * @param {object} callback User-defined callback object.
1118    * @param {string} uri Fully qualified path of resource.
1119    * @param {string} postData POST data to be submitted in addition to HTML form.
1120    * @return {void}
1121    */
1122         uploadFile:function(o, callback, uri, postData){
1123
1124                 // Each iframe has an id prefix of "yuiIO" followed
1125                 // by the unique transaction id.
1126                 var frameId = 'yuiIO' + o.tId,
1127                     uploadEncoding = 'multipart/form-data',
1128                     io = document.getElementById(frameId),
1129                     oConn = this,
1130                         args = (callback && callback.argument)?callback.argument:null,
1131             oElements,i,prop,obj;
1132
1133                 // Track original HTML form attribute values.
1134                 var rawFormAttributes =
1135                 {
1136                         action:this._formNode.getAttribute('action'),
1137                         method:this._formNode.getAttribute('method'),
1138                         target:this._formNode.getAttribute('target')
1139                 };
1140
1141                 // Initialize the HTML form properties in case they are
1142                 // not defined in the HTML form.
1143                 this._formNode.setAttribute('action', uri);
1144                 this._formNode.setAttribute('method', 'POST');
1145                 this._formNode.setAttribute('target', frameId);
1146
1147                 if(YAHOO.env.ua.ie){
1148                         // IE does not respect property enctype for HTML forms.
1149                         // Instead it uses the property - "encoding".
1150                         this._formNode.setAttribute('encoding', uploadEncoding);
1151                 }
1152                 else{
1153                         this._formNode.setAttribute('enctype', uploadEncoding);
1154                 }
1155
1156                 if(postData){
1157                         oElements = this.appendPostData(postData);
1158                 }
1159
1160                 // Start file upload.
1161                 this._formNode.submit();
1162
1163                 // Fire global custom event -- startEvent
1164                 this.startEvent.fire(o, args);
1165
1166                 if(o.startEvent){
1167                         // Fire transaction custom event -- startEvent
1168                         o.startEvent.fire(o, args);
1169                 }
1170
1171                 // Start polling if a callback is present and the timeout
1172                 // property has been defined.
1173                 if(callback && callback.timeout){
1174                         this._timeOut[o.tId] = window.setTimeout(function(){ oConn.abort(o, callback, true); }, callback.timeout);
1175                 }
1176
1177                 // Remove HTML elements created by appendPostData
1178                 if(oElements && oElements.length > 0){
1179                         for(i=0; i < oElements.length; i++){
1180                                 this._formNode.removeChild(oElements[i]);
1181                         }
1182                 }
1183
1184                 // Restore HTML form attributes to their original
1185                 // values prior to file upload.
1186                 for(prop in rawFormAttributes){
1187                         if(YAHOO.lang.hasOwnProperty(rawFormAttributes, prop)){
1188                                 if(rawFormAttributes[prop]){
1189                                         this._formNode.setAttribute(prop, rawFormAttributes[prop]);
1190                                 }
1191                                 else{
1192                                         this._formNode.removeAttribute(prop);
1193                                 }
1194                         }
1195                 }
1196
1197                 // Reset HTML form state properties.
1198                 this.resetFormState();
1199
1200                 // Create the upload callback handler that fires when the iframe
1201                 // receives the load event.  Subsequently, the event handler is detached
1202                 // and the iframe removed from the document.
1203                 var uploadCallback = function()
1204                 {
1205                         if(callback && callback.timeout){
1206                                 window.clearTimeout(oConn._timeOut[o.tId]);
1207                                 delete oConn._timeOut[o.tId];
1208                         }
1209
1210                         // Fire global custom event -- completeEvent
1211                         oConn.completeEvent.fire(o, args);
1212
1213                         if(o.completeEvent){
1214                                 // Fire transaction custom event -- completeEvent
1215                                 o.completeEvent.fire(o, args);
1216                         }
1217
1218                         obj = {
1219                             tId : o.tId,
1220                             argument : callback.argument
1221             };
1222
1223                         try
1224                         {
1225                                 // responseText and responseXML will be populated with the same data from the iframe.
1226                                 // Since the HTTP headers cannot be read from the iframe
1227                                 obj.responseText = io.contentWindow.document.body?io.contentWindow.document.body.innerHTML:io.contentWindow.document.documentElement.textContent;
1228                                 obj.responseXML = io.contentWindow.document.XMLDocument?io.contentWindow.document.XMLDocument:io.contentWindow.document;
1229                         }
1230                         catch(e){}
1231
1232                         if(callback && callback.upload){
1233                                 if(!callback.scope){
1234                                         callback.upload(obj);
1235                                 }
1236                                 else{
1237                                         callback.upload.apply(callback.scope, [obj]);
1238                                 }
1239                         }
1240
1241                         // Fire global custom event -- uploadEvent
1242                         oConn.uploadEvent.fire(obj);
1243
1244                         if(o.uploadEvent){
1245                                 // Fire transaction custom event -- uploadEvent
1246                                 o.uploadEvent.fire(obj);
1247                         }
1248
1249                         YAHOO.util.Event.removeListener(io, "load", uploadCallback);
1250
1251                         setTimeout(
1252                                 function(){
1253                                         document.body.removeChild(io);
1254                                         oConn.releaseObject(o);
1255                                 }, 100);
1256                 };
1257
1258                 // Bind the onload handler to the iframe to detect the file upload response.
1259                 YAHOO.util.Event.addListener(io, "load", uploadCallback);
1260         },
1261
1262   /**
1263    * @description Method to terminate a transaction, if it has not reached readyState 4.
1264    * @method abort
1265    * @public
1266    * @static
1267    * @param {object} o The connection object returned by asyncRequest.
1268    * @param {object} callback  User-defined callback object.
1269    * @param {string} isTimeout boolean to indicate if abort resulted from a callback timeout.
1270    * @return {boolean}
1271    */
1272         abort:function(o, callback, isTimeout)
1273         {
1274                 var abortStatus;
1275                 var args = (callback && callback.argument)?callback.argument:null;
1276
1277
1278                 if(o && o.conn){
1279                         if(this.isCallInProgress(o)){
1280                                 // Issue abort request
1281                                 o.conn.abort();
1282
1283                                 window.clearInterval(this._poll[o.tId]);
1284                                 delete this._poll[o.tId];
1285
1286                                 if(isTimeout){
1287                                         window.clearTimeout(this._timeOut[o.tId]);
1288                                         delete this._timeOut[o.tId];
1289                                 }
1290
1291                                 abortStatus = true;
1292                         }
1293                 }
1294                 else if(o && o.isUpload === true){
1295                         var frameId = 'yuiIO' + o.tId;
1296                         var io = document.getElementById(frameId);
1297
1298                         if(io){
1299                                 // Remove all listeners on the iframe prior to
1300                                 // its destruction.
1301                                 YAHOO.util.Event.removeListener(io, "load");
1302                                 // Destroy the iframe facilitating the transaction.
1303                                 document.body.removeChild(io);
1304
1305                                 if(isTimeout){
1306                                         window.clearTimeout(this._timeOut[o.tId]);
1307                                         delete this._timeOut[o.tId];
1308                                 }
1309
1310                                 abortStatus = true;
1311                         }
1312                 }
1313                 else{
1314                         abortStatus = false;
1315                 }
1316
1317                 if(abortStatus === true){
1318                         // Fire global custom event -- abortEvent
1319                         this.abortEvent.fire(o, args);
1320
1321                         if(o.abortEvent){
1322                                 // Fire transaction custom event -- abortEvent
1323                                 o.abortEvent.fire(o, args);
1324                         }
1325
1326                         this.handleTransactionResponse(o, callback, true);
1327                 }
1328
1329                 return abortStatus;
1330         },
1331
1332   /**
1333    * @description Determines if the transaction is still being processed.
1334    * @method isCallInProgress
1335    * @public
1336    * @static
1337    * @param {object} o The connection object returned by asyncRequest
1338    * @return {boolean}
1339    */
1340         isCallInProgress:function(o)
1341         {
1342                 // if the XHR object assigned to the transaction has not been dereferenced,
1343                 // then check its readyState status.  Otherwise, return false.
1344                 if(o && o.conn){
1345                         return o.conn.readyState !== 4 && o.conn.readyState !== 0;
1346                 }
1347                 else if(o && o.isUpload === true){
1348                         var frameId = 'yuiIO' + o.tId;
1349                         return document.getElementById(frameId)?true:false;
1350                 }
1351                 else{
1352                         return false;
1353                 }
1354         },
1355
1356   /**
1357    * @description Dereference the XHR instance and the connection object after the transaction is completed.
1358    * @method releaseObject
1359    * @private
1360    * @static
1361    * @param {object} o The connection object
1362    * @return {void}
1363    */
1364         releaseObject:function(o)
1365         {
1366                 if(o && o.conn){
1367                         //dereference the XHR instance.
1368                         o.conn = null;
1369
1370
1371                         //dereference the connection object.
1372                         o = null;
1373                 }
1374         }
1375 };
1376 YAHOO.register("connection", YAHOO.util.Connect, {version: "2.7.0", build: "1799"});