src/ajax.js

   1 (function( jQuery ) {
   2
   3 var r20 = /%20/g,
   4         rbracket = /\[\]$/,
   5         rhash = /#.*$/,
   6         rheaders = /^(.*?):\s*(.*?)\r?$/mg, // IE leaves an \r character at EOL
   7         rinput = /^(?:color|date|datetime|email|hidden|month|number|password|range|search|tel|text|time|url|week)$/i,
   8         rnoContent = /^(?:GET|HEAD)$/,
   9         rquery = /\?/,
  10         rscript = /<script\b[^<]*(?:(?!<\/script>)<[^<]*)*<\/script>/gi,
  11         rselectTextarea = /^(?:select|textarea)/i,
  12         rts = /([?&])_=[^&]*/,
  13         rurl = /^(\w+:)?\/\/([^\/?#]+)/,
  14
  15         // Slice function
  16         sliceFunc = Array.prototype.slice,
  17
  18         // Keep a copy of the old load method
  19         _load = jQuery.fn.load;
  20
  21 jQuery.fn.extend({
  22         load: function( url, params, callback ) {
  23                 if ( typeof url !== "string" && _load ) {
  24                         return _load.apply( this, arguments );
  25
  26                 // Don't do a request if no elements are being requested
  27                 } else if ( !this.length ) {
  28                         return this;
  29                 }
  30
  31                 var off = url.indexOf(" ");
  32                 if ( off >= 0 ) {
  33                         var selector = url.slice(off, url.length);
  34                         url = url.slice(0, off);
  35                 }
  36
  37                 // Default to a GET request
  38                 var type = "GET";
  39
  40                 // If the second parameter was provided
  41                 if ( params ) {
  42                         // If it's a function
  43                         if ( jQuery.isFunction( params ) ) {
  44                                 // We assume that it's the callback
  45                                 callback = params;
  46                                 params = null;
  47
  48                         // Otherwise, build a param string
  49                         } else if ( typeof params === "object" ) {
  50                                 params = jQuery.param( params, jQuery.ajaxSettings.traditional );
  51                                 type = "POST";
  52                         }
  53                 }
  54
  55                 var self = this;
  56
  57                 // Request the remote document
  58                 jQuery.ajax({
  59                         url: url,
  60                         type: type,
  61                         dataType: "html",
  62                         data: params,
  63                         complete: function( res, status ) {
  64                                 // If successful, inject the HTML into all the matched elements
  65                                 if ( status === "success" || status === "notmodified" ) {
  66                                         // See if a selector was specified
  67                                         self.html( selector ?
  68                                                 // Create a dummy div to hold the results
  69                                                 jQuery("<div>")
  70                                                         // inject the contents of the document in, removing the scripts
  71                                                         // to avoid any 'Permission Denied' errors in IE
  72                                                         .append(res.responseText.replace(rscript, ""))
  73
  74                                                         // Locate the specified elements
  75                                                         .find(selector) :
  76
  77                                                 // If not, just inject the full result
  78                                                 res.responseText );
  79                                 }
  80
  81                                 if ( callback ) {
  82                                         self.each( callback, [res.responseText, status, res] );
  83                                 }
  84                         }
  85                 });
  86
  87                 return this;
  88         },
  89
  90         serialize: function() {
  91                 return jQuery.param(this.serializeArray());
  92         },
  93
  94         serializeArray: function() {
  95                 return this.map(function(){
  96                         return this.elements ? jQuery.makeArray(this.elements) : this;
  97                 })
  98                 .filter(function(){
  99                         return this.name && !this.disabled &&
 100                                 (this.checked || rselectTextarea.test(this.nodeName) ||
 101                                         rinput.test(this.type));
 102                 })
 103                 .map(function(i, elem){
 104                         var val = jQuery(this).val();
 105
 106                         return val == null ?
 107                                 null :
 108                                 jQuery.isArray(val) ?
 109                                         jQuery.map( val, function(val, i){
 110                                                 return {name: elem.name, value: val.replace(/\r?\n/g, "\r\n")};
 111                                         }) :
 112                                         {name: elem.name, value: val.replace(/\r?\n/g, "\r\n")};
 113                 }).get();
 114         }
 115 });
 116
 117 // Attach a bunch of functions for handling common AJAX events
 118 jQuery.each( "ajaxStart ajaxStop ajaxComplete ajaxError ajaxSuccess ajaxSend".split(" "), function(i,o){
 119         jQuery.fn[o] = function(f){
 120                 return this.bind(o, f);
 121         };
 122 });
 123
 124 jQuery.each( [ "get", "post" ], function( i, method ) {
 125         jQuery[ method ] = function( url, data, callback, type ) {
 126                 // shift arguments if data argument was omited
 127                 if ( jQuery.isFunction( data ) ) {
 128                         type = type || callback;
 129                         callback = data;
 130                         data = null;
 131                 }
 132
 133                 return jQuery.ajax({
 134                         type: method,
 135                         url: url,
 136                         data: data,
 137                         success: callback,
 138                         dataType: type
 139                 });
 140         };
 141 });
 142
 143 jQuery.extend({
 144
 145         getScript: function( url, callback ) {
 146                 return jQuery.get(url, null, callback, "script");
 147         },
 148
 149         getJSON: function( url, data, callback ) {
 150                 return jQuery.get(url, data, callback, "json");
 151         },
 152
 153         ajaxSetup: function( settings ) {
 154                 jQuery.extend( jQuery.ajaxSettings, settings );
 155         },
 156
 157         ajaxSettings: {
 158                 url: location.href,
 159                 global: true,
 160                 type: "GET",
 161                 contentType: "application/x-www-form-urlencoded",
 162                 processData: true,
 163                 async: true,
 164                 /*
 165                 timeout: 0,
 166                 data: null,
 167                 dataType: null,
 168                 dataTypes: null,
 169                 username: null,
 170                 password: null,
 171                 cache: null,
 172                 traditional: false,
 173                 */
 174                 xhr: function() {
 175                         return new window.XMLHttpRequest();
 176                 },
 177
 178                 accepts: {
 179                         xml: "application/xml, text/xml",
 180                         html: "text/html",
 181                         text: "text/plain",
 182                         json: "application/json, text/javascript",
 183                         "*": "*/*"
 184                 },
 185
 186                 contents: {
 187                         xml: /xml/,
 188                         html: /html/,
 189                         json: /json/
 190                 },
 191
 192                 // Prefilters
 193                 // 1) They are useful to introduce custom dataTypes (see transport/jsonp for an example)
 194                 // 2) These are called:
 195                 //    * BEFORE asking for a transport
 196                 //    * AFTER param serialization (s.data is a string if s.processData is true)
 197                 // 3) key is the dataType
 198                 // 4) the catchall symbol "*" can be used
 199                 // 5) execution will start with transport dataType and THEN continue down to "*" if needed
 200                 prefilters: {},
 201
 202                 // Transports bindings
 203                 // 1) key is the dataType
 204                 // 2) the catchall symbol "*" can be used
 205                 // 3) selection will start with transport dataType and THEN go to "*" if needed
 206                 transports: {},
 207
 208                 // List of data converters
 209                 // 1) key format is "source_type destination_type" (a single space in-between)
 210                 // 2) the catchall symbol "*" can be used for source_type
 211                 converters: {
 212
 213                         // Convert anything to text
 214                         "* text": window.String,
 215
 216                         // Text to html (true = no transformation)
 217                         "text html": true,
 218
 219                         // Evaluate text as a json expression
 220                         "text json": jQuery.parseJSON,
 221
 222                         // Parse text as xml
 223                         "text xml": jQuery.parseXML
 224                 }
 225         },
 226
 227         // Main method
 228         // (s is used internally)
 229         ajax: function( url , options , s ) {
 230
 231                 // Handle varargs
 232                 if ( arguments.length === 1 ) {
 233                         options = url;
 234                         url = options ? options.url : undefined;
 235                 }
 236
 237                 // Force options to be an object
 238                 options = options || {};
 239
 240                 // Get the url if provided separately
 241                 options.url = url || options.url;
 242
 243                 // Create the final options object
 244                 s = jQuery.extend( true , {} , jQuery.ajaxSettings , options );
 245
 246                 // We force the original context
 247                 // (plain objects used as context get extended)
 248                 s.context = options.context;
 249
 250                 var // jQuery lists
 251                         jQuery_lastModified = jQuery.lastModified,
 252                         jQuery_etag = jQuery.etag,
 253                         // Callbacks contexts
 254                         callbackContext = s.context || s,
 255                         globalEventContext = s.context ? jQuery( s.context ) : jQuery.event,
 256                         // Deferreds
 257                         deferred = jQuery.Deferred(),
 258                         completeDeferred = jQuery._Deferred(),
 259                         // Headers (they are sent all at once)
 260                         requestHeaders = {},
 261                         // Response headers
 262                         responseHeadersString,
 263                         responseHeaders,
 264                         // transport
 265                         transport,
 266                         // timeout handle
 267                         timeoutTimer,
 268                         // The jXHR state
 269                         state = 0,
 270                         // Loop variable
 271                         i,
 272                         // Fake xhr
 273                         jXHR = {
 274
 275                                 readyState: 0,
 276
 277                                 // Caches the header
 278                                 setRequestHeader: function(name,value) {
 279                                         if ( state === 0 ) {
 280                                                 requestHeaders[ name.toLowerCase() ] = value;
 281                                         }
 282                                         return this;
 283                                 },
 284
 285                                 // Raw string
 286                                 getAllResponseHeaders: function() {
 287                                         return state === 2 ? responseHeadersString : null;
 288                                 },
 289
 290                                 // Builds headers hashtable if needed
 291                                 // (match is used internally)
 292                                 getResponseHeader: function( key , match ) {
 293
 294                                         if ( state !== 2 ) {
 295                                                 return null;
 296                                         }
 297
 298                                         if ( responseHeaders === undefined ) {
 299
 300                                                 responseHeaders = {};
 301
 302                                                 if ( typeof responseHeadersString === "string" ) {
 303
 304                                                         while( ( match = rheaders.exec( responseHeadersString ) ) ) {
 305                                                                 responseHeaders[ match[ 1 ].toLowerCase() ] = match[ 2 ];
 306                                                         }
 307                                                 }
 308                                         }
 309                                         return responseHeaders[ key.toLowerCase() ];
 310                                 },
 311
 312                                 // Cancel the request
 313                                 abort: function( statusText ) {
 314                                         if ( transport && state !== 2 ) {
 315                                                 transport.abort( statusText || "abort" );
 316                                                 done( 0 , statusText );
 317                                         }
 318                                         return this;
 319                                 }
 320                         };
 321
 322                 // Callback for when everything is done
 323                 // It is defined here because jslint complains if it is declared
 324                 // at the end of the function (which would be more logical and readable)
 325                 function done( status , statusText , response , headers) {
 326
 327                         // Called once
 328                         if ( state === 2 ) {
 329                                 return;
 330                         }
 331
 332                         // State is "done" now
 333                         state = 2;
 334
 335                         // Set readyState
 336                         jXHR.readyState = status ? 4 : 0;
 337
 338                         // Cache response headers
 339                         responseHeadersString = headers || "";
 340
 341                         // Clear timeout if it exists
 342                         if ( timeoutTimer ) {
 343                                 clearTimeout(timeoutTimer);
 344                         }
 345
 346                         var // Reference url
 347                                 url = s.url,
 348                                 // and ifModified status
 349                                 ifModified = s.ifModified,
 350
 351                                 // Is it a success?
 352                                 isSuccess = 0,
 353                                 // Stored success
 354                                 success,
 355                                 // Stored error
 356                                 error = statusText;
 357
 358                         // If not timeout, force a jQuery-compliant status text
 359                         if ( statusText != "timeout" ) {
 360                                 statusText = ( status >= 200 && status < 300 ) ?
 361                                         "success" :
 362                                         ( status === 304 ? "notmodified" : "error" );
 363                         }
 364
 365                         // If successful, handle type chaining
 366                         if ( statusText === "success" || statusText === "notmodified" ) {
 367
 368                                 // Set the If-Modified-Since and/or If-None-Match header, if in ifModified mode.
 369                                 if ( s.ifModified ) {
 370
 371                                         var lastModified = jXHR.getResponseHeader("Last-Modified"),
 372                                                 etag = jXHR.getResponseHeader("Etag");
 373
 374                                         if (lastModified) {
 375                                                 jQuery_lastModified[ s.url ] = lastModified;
 376                                         }
 377                                         if (etag) {
 378                                                 jQuery_etag[ s.url ] = etag;
 379                                         }
 380                                 }
 381
 382                                 if ( s.ifModified && statusText === "notmodified" ) {
 383
 384                                         success = null;
 385                                         isSuccess = 1;
 386
 387                                 } else {
 388                                         // Chain data conversions and determine the final value
 389                                         // (if an exception is thrown in the process, it'll be notified as an error)
 390                                         try {
 391
 392                                                 var i,
 393                                                         current,
 394                                                         prev,
 395                                                         checker,
 396                                                         conv,
 397                                                         conv1,
 398                                                         conv2,
 399                                                         convertion,
 400                                                         dataTypes = s.dataTypes,
 401                                                         converters = s.converters,
 402                                                         responses = {
 403                                                                 "xml": "XML",
 404                                                                 "text": "Text"
 405                                                         };
 406
 407                                                 for( i = 0 ; i < dataTypes.length ; i++ ) {
 408
 409                                                         current = dataTypes[ i ];
 410
 411                                                         if ( responses[ current ] ) {
 412                                                                 jXHR[ "response" + responses[ current ] ] = response;
 413                                                                 responses[ current ] = 0;
 414                                                         }
 415
 416                                                         if ( i ) {
 417
 418                                                                 prev = dataTypes[ i - 1 ];
 419
 420                                                                 if ( prev !== "*" && current !== "*" && prev !== current ) {
 421
 422                                                                         conv = converters[ ( conversion = prev + " " + current ) ] ||
 423                                                                                 converters[ "* " + current ];
 424
 425                                                                         conv1 = conv2 = 0;
 426
 427                                                                         if ( ! conv && prev !== "text" && current !== "text" ) {
 428                                                                                 conv1 = converters[ prev + " text" ] || converters[ "* text" ];
 429                                                                                 conv2 = converters[ "text " + current ];
 430                                                                                 if ( conv1 === true ) {
 431                                                                                         conv = conv2;
 432                                                                                 } else if ( conv2 === true ) {
 433                                                                                         conv = conv1;
 434                                                                                 }
 435                                                                         }
 436
 437                                                                         if ( ! ( conv || conv1 && conv2 ) ) {
 438                                                                                 throw conversion;
 439                                                                         }
 440
 441                                                                         if ( conv !== true ) {
 442                                                                                 response = conv ? conv( response ) : conv2( conv1( response ) );
 443                                                                         }
 444                                                                 }
 445                                                         } else if ( s.dataFilter ) {
 446
 447                                                                 response = s.dataFilter( response );
 448                                                                 dataTypes = s.dataTypes;
 449                                                         }
 450                                                 }
 451
 452                                                 // We have a real success
 453                                                 success = response;
 454                                                 isSuccess = 1;
 455
 456                                         } catch(e) {
 457
 458                                                 statusText = "parsererror";
 459                                                 error = "" + e;
 460
 461                                         }
 462                                 }
 463
 464                         } else { // if not success, mark it as an error
 465
 466                                         error = error || statusText;
 467
 468                                         // Set responseText if needed
 469                                         if ( response ) {
 470                                                 jXHR.responseText = response;
 471                                         }
 472                         }
 473
 474                         // Set data for the fake xhr object
 475                         jXHR.status = status;
 476                         jXHR.statusText = statusText;
 477
 478                         // Success/Error
 479                         if ( isSuccess ) {
 480                                 deferred.fire( callbackContext , [ success , statusText , jXHR ] );
 481                         } else {
 482                                 deferred.fireReject( callbackContext , [ jXHR , statusText , error ] );
 483                         }
 484
 485                         if ( s.global ) {
 486                                 globalEventContext.trigger( "ajax" + ( isSuccess ? "Success" : "Error" ) ,
 487                                                 [ jXHR , s , isSuccess ? success : error ] );
 488                         }
 489
 490                         // Complete
 491                         completeDeferred.fire( callbackContext, [ jXHR , statusText ] );
 492
 493                         if ( s.global ) {
 494                                 globalEventContext.trigger( "ajaxComplete" , [ jXHR , s] );
 495                                 // Handle the global AJAX counter
 496                                 if ( ! --jQuery.active ) {
 497                                         jQuery.event.trigger( "ajaxStop" );
 498                                 }
 499                         }
 500                 }
 501
 502                 // Attach deferreds
 503                 deferred.promise( jXHR );
 504                 jXHR.success = jXHR.done;
 505                 jXHR.error = jXHR.fail;
 506                 jXHR.complete = completeDeferred.done;
 507
 508                 // Remove hash character (#7531: and string promotion)
 509                 s.url = ( "" + s.url ).replace( rhash , "" );
 510
 511                 // Uppercase the type
 512                 s.type = s.type.toUpperCase();
 513
 514                 // Determine if request has content
 515                 s.hasContent = ! rnoContent.test( s.type );
 516
 517                 // Extract dataTypes list
 518                 s.dataTypes = jQuery.trim( s.dataType || "*" ).toLowerCase().split( /\s+/ );
 519
 520                 // Determine if a cross-domain request is in order
 521                 var parts = rurl.exec( s.url.toLowerCase() ),
 522                         loc = location;
 523                 s.crossDomain = !!( parts && ( parts[ 1 ] && parts[ 1 ] != loc.protocol || parts[ 2 ] != loc.host ) );
 524
 525                 // Convert data if not already a string
 526                 if ( s.data && s.processData && typeof s.data != "string" ) {
 527                         s.data = jQuery.param( s.data , s.traditional );
 528                 }
 529
 530                 // Watch for a new set of requests
 531                 if ( s.global && jQuery.active++ === 0 ) {
 532                         jQuery.event.trigger( "ajaxStart" );
 533                 }
 534
 535                 // Get transport
 536                 transport = jQuery.ajax.prefilter( s ).transport( s );
 537
 538                 // If no transport, we auto-abort
 539                 if ( ! transport ) {
 540
 541                         done( 0 , "transport not found" );
 542                         jXHR = false;
 543
 544                 } else {
 545
 546                         // More options handling for requests with no content
 547                         if ( ! s.hasContent ) {
 548
 549                                 // If data is available, append data to url
 550                                 if ( s.data ) {
 551                                         s.url += ( rquery.test( s.url ) ? "&" : "?" ) + s.data;
 552                                 }
 553
 554                                 // Add anti-cache in url if needed
 555                                 if ( s.cache === false ) {
 556
 557                                         var ts = jQuery.now(),
 558                                                 // try replacing _= if it is there
 559                                                 ret = s.url.replace( rts , "$1_=" + ts );
 560
 561                                         // if nothing was replaced, add timestamp to the end
 562                                         s.url = ret + ( (ret == s.url ) ? ( rquery.test( s.url ) ? "&" : "?" ) + "_=" + ts : "");
 563                                 }
 564                         }
 565
 566                         // Set the correct header, if data is being sent
 567                         if ( s.data && s.hasContent && s.contentType !== false || options.contentType ) {
 568                                 requestHeaders[ "content-type" ] = s.contentType;
 569                         }
 570
 571                         // Set the If-Modified-Since and/or If-None-Match header, if in ifModified mode.
 572                         if ( s.ifModified ) {
 573                                 if ( jQuery_lastModified[ s.url ] ) {
 574                                         requestHeaders[ "if-modified-since" ] = jQuery_lastModified[ s.url ];
 575                                 }
 576                                 if ( jQuery_etag[ s.url ] ) {
 577                                         requestHeaders[ "if-none-match" ] = jQuery_etag[ s.url ];
 578                                 }
 579                         }
 580
 581                         // Set the Accepts header for the server, depending on the dataType
 582                         requestHeaders.accept = s.dataTypes[ 0 ] && s.accepts[ s.dataTypes[ 0 ] ] ?
 583                                 s.accepts[ s.dataTypes[ 0 ] ] + ( s.dataTypes[ 0 ] !== "*" ? ", */*; q=0.01" : "" ) :
 584                                 s.accepts[ "*" ];
 585
 586                         // Check for headers option
 587                         for ( i in s.headers ) {
 588                                 requestHeaders[ i.toLowerCase() ] = s.headers[ i ];
 589                         }
 590
 591                         // Allow custom headers/mimetypes and early abort
 592                         if ( s.beforeSend && ( s.beforeSend.call( callbackContext , jXHR , s ) === false || state === 2 ) ) {
 593
 594                                         // Abort if not done already
 595                                         done( 0 , "abort" );
 596                                         jXHR = false;
 597
 598                         } else {
 599
 600                                 // Set state as sending
 601                                 state = 1;
 602                                 jXHR.readyState = 1;
 603
 604                                 // Install callbacks on deferreds
 605                                 for ( i in { success:1, error:1, complete:1 } ) {
 606                                         jXHR[ i ]( s[ i ] );
 607                                 }
 608
 609                                 // Send global event
 610                                 if ( s.global ) {
 611                                         globalEventContext.trigger( "ajaxSend" , [ jXHR , s ] );
 612                                 }
 613
 614                                 // Timeout
 615                                 if ( s.async && s.timeout > 0 ) {
 616                                         timeoutTimer = setTimeout(function(){
 617                                                 jXHR.abort( "timeout" );
 618                                         }, s.timeout);
 619                                 }
 620
 621                                 // Try to send
 622                                 try {
 623                                         transport.send(requestHeaders, done);
 624                                 } catch (e) {
 625                                         // Propagate exception as error if not done
 626                                         if ( status === 1 ) {
 627
 628                                                 done(0, "error", "" + e);
 629                                                 jXHR = false;
 630
 631                                         // Simply rethrow otherwise
 632                                         } else {
 633                                                 jQuery.error(e);
 634                                         }
 635                                 }
 636                         }
 637                 }
 638
 639                 return jXHR;
 640         },
 641
 642         // Serialize an array of form elements or a set of
 643         // key/values into a query string
 644         param: function( a, traditional ) {
 645                 var s = [],
 646                         add = function( key, value ) {
 647                                 // If value is a function, invoke it and return its value
 648                                 value = jQuery.isFunction(value) ? value() : value;
 649                                 s[ s.length ] = encodeURIComponent(key) + "=" + encodeURIComponent(value);
 650                         };
 651
 652                 // Set traditional to true for jQuery <= 1.3.2 behavior.
 653                 if ( traditional === undefined ) {
 654                         traditional = jQuery.ajaxSettings.traditional;
 655                 }
 656
 657                 // If an array was passed in, assume that it is an array of form elements.
 658                 if ( jQuery.isArray(a) || a.jquery ) {
 659                         // Serialize the form elements
 660                         jQuery.each( a, function() {
 661                                 add( this.name, this.value );
 662                         });
 663
 664                 } else {
 665                         // If traditional, encode the "old" way (the way 1.3.2 or older
 666                         // did it), otherwise encode params recursively.
 667                         for ( var prefix in a ) {
 668                                 buildParams( prefix, a[prefix], traditional, add );
 669                         }
 670                 }
 671
 672                 // Return the resulting serialization
 673                 return s.join("&").replace(r20, "+");
 674         }
 675 });
 676
 677 function buildParams( prefix, obj, traditional, add ) {
 678         if ( jQuery.isArray(obj) && obj.length ) {
 679                 // Serialize array item.
 680                 jQuery.each( obj, function( i, v ) {
 681                         if ( traditional || rbracket.test( prefix ) ) {
 682                                 // Treat each array item as a scalar.
 683                                 add( prefix, v );
 684
 685                         } else {
 686                                 // If array item is non-scalar (array or object), encode its
 687                                 // numeric index to resolve deserialization ambiguity issues.
 688                                 // Note that rack (as of 1.0.0) can't currently deserialize
 689                                 // nested arrays properly, and attempting to do so may cause
 690                                 // a server error. Possible fixes are to modify rack's
 691                                 // deserialization algorithm or to provide an option or flag
 692                                 // to force array serialization to be shallow.
 693                                 buildParams( prefix + "[" + ( typeof v === "object" || jQuery.isArray(v) ? i : "" ) + "]", v, traditional, add );
 694                         }
 695                 });
 696
 697         } else if ( !traditional && obj != null && typeof obj === "object" ) {
 698                 // If we see an array here, it is empty and should be treated as an empty
 699                 // object
 700                 if ( jQuery.isArray( obj ) || jQuery.isEmptyObject( obj ) ) {
 701                         add( prefix, "" );
 702
 703                 // Serialize object item.
 704                 } else {
 705                         jQuery.each( obj, function( k, v ) {
 706                                 buildParams( prefix + "[" + k + "]", v, traditional, add );
 707                         });
 708                 }
 709
 710         } else {
 711                 // Serialize scalar item.
 712                 add( prefix, obj );
 713         }
 714 }
 715
 716 // This is still on the jQuery object... for now
 717 // Want to move this to jQuery.ajax some day
 718 jQuery.extend({
 719
 720         // Counter for holding the number of active queries
 721         active: 0,
 722
 723         // Last-Modified header cache for next request
 724         lastModified: {},
 725         etag: {}
 726
 727 });
 728
 729 //Execute or select from functions in a given structure of options
 730 function ajax_selectOrExecute( structure , s ) {
 731
 732         var dataTypes = s.dataTypes,
 733                 transportDataType,
 734                 list,
 735                 selected,
 736                 i,
 737                 length,
 738                 checked = {},
 739                 flag,
 740                 noSelect = structure !== "transports";
 741
 742         function initSearch( dataType ) {
 743
 744                 flag = transportDataType !== dataType && ! checked[ dataType ];
 745
 746                 if ( flag ) {
 747
 748                         checked[ dataType ] = 1;
 749                         transportDataType = dataType;
 750                         list = s[ structure ][ dataType ];
 751                         i = -1;
 752                         length = list ? list.length : 0 ;
 753                 }
 754
 755                 return flag;
 756         }
 757
 758         initSearch( dataTypes[ 0 ] );
 759
 760         for ( i = 0 ; ( noSelect || ! selected ) && i <= length ; i++ ) {
 761
 762                 if ( i === length ) {
 763
 764                         initSearch( "*" );
 765
 766                 } else {
 767
 768                         selected = list[ i ]( s , determineDataType );
 769
 770                         // If we got redirected to another dataType
 771                         // Search there (if not in progress or already tried)
 772                         if ( typeof( selected ) === "string" &&
 773                                 initSearch( selected ) ) {
 774
 775                                 dataTypes.unshift( selected );
 776                                 selected = 0;
 777                         }
 778                 }
 779         }
 780
 781         return noSelect ? jQuery.ajax : selected;
 782 }
 783
 784 // Add an element to one of the structures in ajaxSettings
 785 function ajax_addElement( structure , args ) {
 786
 787         var i,
 788                 start = 0,
 789                 length = args.length,
 790                 dataTypes = [ "*" ],
 791                 dLength = 1,
 792                 dataType,
 793                 functors = [],
 794                 first,
 795                 append,
 796                 list;
 797
 798         if ( length ) {
 799
 800                 first = jQuery.type( args[ 0 ] );
 801
 802                 if ( first === "object" ) {
 803                         return ajax_selectOrExecute( structure , args[ 0 ] );
 804                 }
 805
 806                 structure = jQuery.ajaxSettings[ structure ];
 807
 808                 if ( first !== "function" ) {
 809
 810                         dataTypes = args[ 0 ].toLowerCase().split(/\s+/);
 811                         dLength = dataTypes.length;
 812                         start = 1;
 813
 814                 }
 815
 816                 if ( dLength && start < length ) {
 817
 818                         functors = sliceFunc.call( args , start );
 819
 820                         for( i = 0 ; i < dLength ; i++ ) {
 821
 822                                 dataType = dataTypes[ i ];
 823
 824                                 first = /^\+/.test( dataType );
 825
 826                                 if (first) {
 827                                         dataType = dataType.substr(1);
 828                                 }
 829
 830                                 if ( dataType !== "" ) {
 831
 832                                         append = Array.prototype[ first ? "unshift" : "push" ];
 833                                         list = structure[ dataType ] = structure[ dataType ] || [];
 834                                         append.apply( list , functors );
 835                                 }
 836                         }
 837                 }
 838         }
 839
 840         return jQuery.ajax;
 841 }
 842
 843 // Install prefilter & transport methods
 844 jQuery.each( [ "prefilter" , "transport" ] , function( _ , name ) {
 845         _ = name + "s";
 846         jQuery.ajax[ name ] = function() {
 847                 return ajax_addElement( _ , arguments );
 848         };
 849 } );
 850
 851 // Utility function that handles dataType when response is received
 852 // (for those transports that can give text or xml responses)
 853 function determineDataType( s , ct , text , xml ) {
 854
 855         var contents = s.contents,
 856                 type,
 857                 regexp,
 858                 dataTypes = s.dataTypes,
 859                 transportDataType = dataTypes[0],
 860                 response;
 861
 862         // Auto (xml, json, script or text determined given headers)
 863         if ( transportDataType === "*" ) {
 864
 865                 for ( type in contents ) {
 866                         if ( ( regexp = contents[ type ] ) && regexp.test( ct ) ) {
 867                                 transportDataType = dataTypes[0] = type;
 868                                 break;
 869                         }
 870                 }
 871         }
 872
 873         // xml and parsed as such
 874         if ( transportDataType === "xml" &&
 875                 xml &&
 876                 xml.documentElement /* #4958 */ ) {
 877
 878                 response = xml;
 879
 880         // Text response was provided
 881         } else {
 882
 883                 response = text;
 884
 885                 // If it's not really text, defer to converters
 886                 if ( transportDataType !== "text" ) {
 887                         dataTypes.unshift( "text" );
 888                 }
 889
 890         }
 891
 892         return response;
 893 }
 894
 895 /*
 896  * Create the request object; Microsoft failed to properly
 897  * implement the XMLHttpRequest in IE7 (can't request local files),
 898  * so we use the ActiveXObject when it is available
 899  * Additionally XMLHttpRequest can be disabled in IE7/IE8 so
 900  * we need a fallback.
 901  */
 902 if ( window.ActiveXObject ) {
 903         jQuery.ajaxSettings.xhr = function() {
 904         if ( window.location.protocol !== "file:" ) {
 905                 try {
 906                         return new window.XMLHttpRequest();
 907                 } catch( xhrError ) {}
 908         }
 909
 910         try {
 911                 return new window.ActiveXObject("Microsoft.XMLHTTP");
 912         } catch( activeError ) {}
 913         };
 914 }
 915
 916 var testXHR = jQuery.ajaxSettings.xhr();
 917
 918 // Does this browser support XHR requests?
 919 jQuery.support.ajax = !!testXHR;
 920
 921 // Does this browser support crossDomain XHR requests
 922 jQuery.support.cors = testXHR && "withCredentials" in testXHR;
 923
 924 })( jQuery );