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+:)?\/\/([^\/?#:]+)(?::(\d+))?/,
  14         rCRLF = /\r?\n/g,
  15
  16         // Slice function
  17         sliceFunc = Array.prototype.slice,
  18
  19         // Keep a copy of the old load method
  20         _load = jQuery.fn.load;
  21
  22 jQuery.fn.extend({
  23         load: function( url, params, callback ) {
  24                 if ( typeof url !== "string" && _load ) {
  25                         return _load.apply( this, arguments );
  26
  27                 // Don't do a request if no elements are being requested
  28                 } else if ( !this.length ) {
  29                         return this;
  30                 }
  31
  32                 var off = url.indexOf(" ");
  33                 if ( off >= 0 ) {
  34                         var selector = url.slice(off, url.length);
  35                         url = url.slice(0, off);
  36                 }
  37
  38                 // Default to a GET request
  39                 var type = "GET";
  40
  41                 // If the second parameter was provided
  42                 if ( params ) {
  43                         // If it's a function
  44                         if ( jQuery.isFunction( params ) ) {
  45                                 // We assume that it's the callback
  46                                 callback = params;
  47                                 params = null;
  48
  49                         // Otherwise, build a param string
  50                         } else if ( typeof params === "object" ) {
  51                                 params = jQuery.param( params, jQuery.ajaxSettings.traditional );
  52                                 type = "POST";
  53                         }
  54                 }
  55
  56                 var self = this;
  57
  58                 // Request the remote document
  59                 jQuery.ajax({
  60                         url: url,
  61                         type: type,
  62                         dataType: "html",
  63                         data: params,
  64                         // Complete callback (responseText is used internally)
  65                         complete: function( jXHR, status, responseText ) {
  66                                 // Store the response as specified by the jXHR object
  67                                 responseText = jXHR.responseText;
  68                                 // If successful, inject the HTML into all the matched elements
  69                                 if ( jXHR.isResolved() ) {
  70                                         // #4825: Get the actual response in case
  71                                         // a dataFilter is present in ajaxSettings
  72                                         jXHR.done(function( r ) {
  73                                                 responseText = r;
  74                                         });
  75                                         // See if a selector was specified
  76                                         self.html( selector ?
  77                                                 // Create a dummy div to hold the results
  78                                                 jQuery("<div>")
  79                                                         // inject the contents of the document in, removing the scripts
  80                                                         // to avoid any 'Permission Denied' errors in IE
  81                                                         .append(responseText.replace(rscript, ""))
  82
  83                                                         // Locate the specified elements
  84                                                         .find(selector) :
  85
  86                                                 // If not, just inject the full result
  87                                                 responseText );
  88                                 }
  89
  90                                 if ( callback ) {
  91                                         self.each( callback, [responseText, status, jXHR] );
  92                                 }
  93                         }
  94                 });
  95
  96                 return this;
  97         },
  98
  99         serialize: function() {
 100                 return jQuery.param(this.serializeArray());
 101         },
 102
 103         serializeArray: function() {
 104                 return this.map(function(){
 105                         return this.elements ? jQuery.makeArray(this.elements) : this;
 106                 })
 107                 .filter(function(){
 108                         return this.name && !this.disabled &&
 109                                 (this.checked || rselectTextarea.test(this.nodeName) ||
 110                                         rinput.test(this.type));
 111                 })
 112                 .map(function(i, elem){
 113                         var val = jQuery(this).val();
 114
 115                         return val == null ?
 116                                 null :
 117                                 jQuery.isArray(val) ?
 118                                         jQuery.map( val, function(val, i){
 119                                                 return { name: elem.name, value: val.replace(rCRLF, "\r\n") };
 120                                         }) :
 121                                         { name: elem.name, value: val.replace(rCRLF, "\r\n") };
 122                 }).get();
 123         }
 124 });
 125
 126 // Attach a bunch of functions for handling common AJAX events
 127 jQuery.each( "ajaxStart ajaxStop ajaxComplete ajaxError ajaxSuccess ajaxSend".split(" "), function(i,o){
 128         jQuery.fn[o] = function(f){
 129                 return this.bind(o, f);
 130         };
 131 });
 132
 133 jQuery.each( [ "get", "post" ], function( i, method ) {
 134         jQuery[ method ] = function( url, data, callback, type ) {
 135                 // shift arguments if data argument was omited
 136                 if ( jQuery.isFunction( data ) ) {
 137                         type = type || callback;
 138                         callback = data;
 139                         data = null;
 140                 }
 141
 142                 return jQuery.ajax({
 143                         type: method,
 144                         url: url,
 145                         data: data,
 146                         success: callback,
 147                         dataType: type
 148                 });
 149         };
 150 });
 151
 152 jQuery.extend({
 153
 154         getScript: function( url, callback ) {
 155                 return jQuery.get(url, null, callback, "script");
 156         },
 157
 158         getJSON: function( url, data, callback ) {
 159                 return jQuery.get(url, data, callback, "json");
 160         },
 161
 162         ajaxSetup: function( settings ) {
 163                 jQuery.extend( true, jQuery.ajaxSettings, settings );
 164                 return this;
 165         },
 166
 167         ajaxSettings: {
 168                 url: location.href,
 169                 global: true,
 170                 type: "GET",
 171                 contentType: "application/x-www-form-urlencoded",
 172                 processData: true,
 173                 async: true,
 174                 /*
 175                 timeout: 0,
 176                 data: null,
 177                 dataType: null,
 178                 username: null,
 179                 password: null,
 180                 cache: null,
 181                 traditional: false,
 182                 headers: {},
 183                 crossDomain: null,
 184                 */
 185
 186                 accepts: {
 187                         xml: "application/xml, text/xml",
 188                         html: "text/html",
 189                         text: "text/plain",
 190                         json: "application/json, text/javascript",
 191                         "*": "*/*"
 192                 },
 193
 194                 contents: {
 195                         xml: /xml/,
 196                         html: /html/,
 197                         json: /json/
 198                 },
 199
 200                 // Prefilters
 201                 // 1) They are useful to introduce custom dataTypes (see transport/jsonp for an example)
 202                 // 2) These are called:
 203                 //    * BEFORE asking for a transport
 204                 //    * AFTER param serialization (s.data is a string if s.processData is true)
 205                 // 3) key is the dataType
 206                 // 4) the catchall symbol "*" can be used
 207                 // 5) execution will start with transport dataType and THEN continue down to "*" if needed
 208                 prefilters: {},
 209
 210                 // Transports bindings
 211                 // 1) key is the dataType
 212                 // 2) the catchall symbol "*" can be used
 213                 // 3) selection will start with transport dataType and THEN go to "*" if needed
 214                 transports: {},
 215
 216                 // List of data converters
 217                 // 1) key format is "source_type destination_type" (a single space in-between)
 218                 // 2) the catchall symbol "*" can be used for source_type
 219                 converters: {
 220
 221                         // Convert anything to text
 222                         "* text": window.String,
 223
 224                         // Text to html (true = no transformation)
 225                         "text html": true,
 226
 227                         // Evaluate text as a json expression
 228                         "text json": jQuery.parseJSON,
 229
 230                         // Parse text as xml
 231                         "text xml": jQuery.parseXML
 232                 }
 233         },
 234
 235         // Main method
 236         ajax: function( url , options ) {
 237
 238                 // Handle varargs
 239                 if ( arguments.length === 1 ) {
 240                         options = url;
 241                         url = options ? options.url : undefined;
 242                 }
 243
 244                 // Force options to be an object
 245                 options = options || {};
 246
 247                 // Get the url if provided separately
 248                 options.url = url || options.url;
 249
 250                 var // Create the final options object
 251                         s = jQuery.extend( true , {} , jQuery.ajaxSettings , options ),
 252                         // jQuery lists
 253                         jQuery_lastModified = jQuery.lastModified,
 254                         jQuery_etag = jQuery.etag,
 255                         // Callbacks contexts
 256                         callbackContext = options.context || s.context || s,
 257                         globalEventContext = callbackContext === s ? jQuery.event : jQuery( callbackContext ),
 258                         // Deferreds
 259                         deferred = jQuery.Deferred(),
 260                         completeDeferred = jQuery._Deferred(),
 261                         // Status-dependent callbacks
 262                         statusCode = s.statusCode || {},
 263                         // Headers (they are sent all at once)
 264                         requestHeaders = {},
 265                         // Response headers
 266                         responseHeadersString,
 267                         responseHeaders,
 268                         // transport
 269                         transport,
 270                         // timeout handle
 271                         timeoutTimer,
 272                         // Cross-domain detection vars
 273                         loc = document.location,
 274                         parts,
 275                         // The jXHR state
 276                         state = 0,
 277                         // Loop variable
 278                         i,
 279                         // Fake xhr
 280                         jXHR = {
 281
 282                                 readyState: 0,
 283
 284                                 // Caches the header
 285                                 setRequestHeader: function(name,value) {
 286                                         if ( state === 0 ) {
 287                                                 requestHeaders[ name.toLowerCase() ] = value;
 288                                         }
 289                                         return this;
 290                                 },
 291
 292                                 // Raw string
 293                                 getAllResponseHeaders: function() {
 294                                         return state === 2 ? responseHeadersString : null;
 295                                 },
 296
 297                                 // Builds headers hashtable if needed
 298                                 getResponseHeader: function( key ) {
 299
 300                                         var match;
 301
 302                                         if ( state === 2 ) {
 303
 304                                                 if ( !responseHeaders ) {
 305
 306                                                         responseHeaders = {};
 307
 308                                                         while( ( match = rheaders.exec( responseHeadersString ) ) ) {
 309                                                                 responseHeaders[ match[ 1 ].toLowerCase() ] = match[ 2 ];
 310                                                         }
 311                                                 }
 312                                                 match = responseHeaders[ key.toLowerCase() ];
 313
 314                                         }
 315
 316                                         return match || null;
 317                                 },
 318
 319                                 // Cancel the request
 320                                 abort: function( statusText ) {
 321                                         if ( transport ) {
 322                                                 transport.abort( statusText || "abort" );
 323                                         }
 324                                         done( 0 , statusText );
 325                                         return this;
 326                                 }
 327                         };
 328
 329                 // We force the original context
 330                 // (plain objects used as context get extended)
 331                 s.context = options.context;
 332
 333                 // Callback for when everything is done
 334                 // It is defined here because jslint complains if it is declared
 335                 // at the end of the function (which would be more logical and readable)
 336                 function done( status , statusText , response , headers) {
 337
 338                         // Called once
 339                         if ( state === 2 ) {
 340                                 return;
 341                         }
 342
 343                         // State is "done" now
 344                         state = 2;
 345
 346                         // Dereference transport for early garbage collection
 347                         // (no matter how long the jXHR transport will be used
 348                         transport = undefined;
 349
 350                         // Set readyState
 351                         jXHR.readyState = status ? 4 : 0;
 352
 353                         // Cache response headers
 354                         responseHeadersString = headers || "";
 355
 356                         // Clear timeout if it exists
 357                         if ( timeoutTimer ) {
 358                                 clearTimeout(timeoutTimer);
 359                         }
 360
 361                         var // Reference url
 362                                 url = s.url,
 363                                 // and ifModified status
 364                                 ifModified = s.ifModified,
 365
 366                                 // Is it a success?
 367                                 isSuccess = 0,
 368                                 // Stored success
 369                                 success,
 370                                 // Stored error
 371                                 error,
 372
 373                                 // Keep track of statusCode callbacks
 374                                 oldStatusCode = statusCode;
 375
 376                         statusCode = undefined;
 377
 378                         // If successful, handle type chaining
 379                         if ( status >= 200 && status < 300 || status === 304 ) {
 380
 381                                 // Set the If-Modified-Since and/or If-None-Match header, if in ifModified mode.
 382                                 if ( s.ifModified ) {
 383
 384                                         var lastModified = jXHR.getResponseHeader("Last-Modified"),
 385                                                 etag = jXHR.getResponseHeader("Etag");
 386
 387                                         if (lastModified) {
 388                                                 jQuery_lastModified[ s.url ] = lastModified;
 389                                         }
 390                                         if (etag) {
 391                                                 jQuery_etag[ s.url ] = etag;
 392                                         }
 393                                 }
 394
 395                                 // If not modified
 396                                 if ( status === 304 ) {
 397
 398                                         // Set the statusText accordingly
 399                                         statusText = "notmodified";
 400                                         // Mark as a success
 401                                         isSuccess = 1;
 402
 403                                 // If we have data
 404                                 } else {
 405
 406                                         // Set the statusText accordingly
 407                                         statusText = "success";
 408
 409                                         // Chain data conversions and determine the final value
 410                                         // (if an exception is thrown in the process, it'll be notified as an error)
 411                                         try {
 412
 413                                                 var i,
 414                                                         // Current dataType
 415                                                         current,
 416                                                         // Previous dataType
 417                                                         prev,
 418                                                         // Conversion expression
 419                                                         conversion,
 420                                                         // Conversion function
 421                                                         conv,
 422                                                         // Conversion functions (when text is used in-between)
 423                                                         conv1,
 424                                                         conv2,
 425                                                         // Local references to dataTypes & converters
 426                                                         dataTypes = s.dataTypes,
 427                                                         converters = s.converters,
 428                                                         // DataType to responseXXX field mapping
 429                                                         responses = {
 430                                                                 "xml": "XML",
 431                                                                 "text": "Text"
 432                                                         };
 433
 434                                                 // For each dataType in the chain
 435                                                 for( i = 0 ; i < dataTypes.length ; i++ ) {
 436
 437                                                         current = dataTypes[ i ];
 438
 439                                                         // If a responseXXX field for this dataType exists
 440                                                         // and if it hasn't been set yet
 441                                                         if ( responses[ current ] ) {
 442                                                                 // Set it
 443                                                                 jXHR[ "response" + responses[ current ] ] = response;
 444                                                                 // Mark it as set
 445                                                                 responses[ current ] = 0;
 446                                                         }
 447
 448                                                         // If this is not the first element
 449                                                         if ( i ) {
 450
 451                                                                 // Get the dataType to convert from
 452                                                                 prev = dataTypes[ i - 1 ];
 453
 454                                                                 // If no catch-all and dataTypes are actually different
 455                                                                 if ( prev !== "*" && current !== "*" && prev !== current ) {
 456
 457                                                                         // Get the converter
 458                                                                         conversion = prev + " " + current;
 459                                                                         conv = converters[ conversion ] || converters[ "* " + current ];
 460
 461                                                                         conv1 = conv2 = 0;
 462
 463                                                                         // If there is no direct converter and none of the dataTypes is text
 464                                                                         if ( ! conv && prev !== "text" && current !== "text" ) {
 465                                                                                 // Try with text in-between
 466                                                                                 conv1 = converters[ prev + " text" ] || converters[ "* text" ];
 467                                                                                 conv2 = converters[ "text " + current ];
 468                                                                                 // Revert back to a single converter
 469                                                                                 // if one of the converter is an equivalence
 470                                                                                 if ( conv1 === true ) {
 471                                                                                         conv = conv2;
 472                                                                                 } else if ( conv2 === true ) {
 473                                                                                         conv = conv1;
 474                                                                                 }
 475                                                                         }
 476                                                                         // If we found no converter, dispatch an error
 477                                                                         if ( ! ( conv || conv1 && conv2 ) ) {
 478                                                                                 throw conversion;
 479                                                                         }
 480                                                                         // If found converter is not an equivalence
 481                                                                         if ( conv !== true ) {
 482                                                                                 // Convert with 1 or 2 converters accordingly
 483                                                                                 response = conv ? conv( response ) : conv2( conv1( response ) );
 484                                                                         }
 485                                                                 }
 486                                                         // If it is the first element of the chain
 487                                                         // and we have a dataFilter
 488                                                         } else if ( s.dataFilter ) {
 489                                                                 // Apply the dataFilter
 490                                                                 response = s.dataFilter( response , current );
 491                                                                 // Get dataTypes again in case the filter changed them
 492                                                                 dataTypes = s.dataTypes;
 493                                                         }
 494                                                 }
 495                                                 // End of loop
 496
 497                                                 // We have a real success
 498                                                 success = response;
 499                                                 isSuccess = 1;
 500
 501                                         // If an exception was thrown
 502                                         } catch(e) {
 503
 504                                                 // We have a parsererror
 505                                                 statusText = "parsererror";
 506                                                 error = "" + e;
 507
 508                                         }
 509                                 }
 510
 511                         // if not success, mark it as an error
 512                         } else {
 513
 514                                         error = statusText = statusText || "error";
 515
 516                                         // Set responseText if needed
 517                                         if ( response ) {
 518                                                 jXHR.responseText = response;
 519                                         }
 520                         }
 521
 522                         // Set data for the fake xhr object
 523                         jXHR.status = status;
 524                         jXHR.statusText = statusText;
 525
 526                         // Success/Error
 527                         if ( isSuccess ) {
 528                                 deferred.fire( callbackContext , [ success , statusText , jXHR ] );
 529                         } else {
 530                                 deferred.fireReject( callbackContext , [ jXHR , statusText , error ] );
 531                         }
 532
 533                         // Status-dependent callbacks
 534                         jXHR.statusCode( oldStatusCode );
 535
 536                         if ( s.global ) {
 537                                 globalEventContext.trigger( "ajax" + ( isSuccess ? "Success" : "Error" ) ,
 538                                                 [ jXHR , s , isSuccess ? success : error ] );
 539                         }
 540
 541                         // Complete
 542                         completeDeferred.fire( callbackContext, [ jXHR , statusText ] );
 543
 544                         if ( s.global ) {
 545                                 globalEventContext.trigger( "ajaxComplete" , [ jXHR , s] );
 546                                 // Handle the global AJAX counter
 547                                 if ( ! --jQuery.active ) {
 548                                         jQuery.event.trigger( "ajaxStop" );
 549                                 }
 550                         }
 551                 }
 552
 553                 // Attach deferreds
 554                 deferred.promise( jXHR );
 555                 jXHR.success = jXHR.done;
 556                 jXHR.error = jXHR.fail;
 557                 jXHR.complete = completeDeferred.done;
 558
 559                 // Status-dependent callbacks
 560                 jXHR.statusCode = function( map ) {
 561                         if ( map ) {
 562                                 var tmp;
 563                                 if ( statusCode ) {
 564                                         for( tmp in map ) {
 565                                                 statusCode[ tmp ] = [ statusCode[ tmp ] , map[ tmp ] ];
 566                                         }
 567                                 } else {
 568                                         tmp = map[ jXHR.status ];
 569                                         jXHR.done( tmp ).fail( tmp );
 570                                 }
 571                         }
 572                         return this;
 573                 };
 574
 575                 // Remove hash character (#7531: and string promotion)
 576                 s.url = ( "" + s.url ).replace( rhash , "" );
 577
 578                 // Extract dataTypes list
 579                 s.dataTypes = jQuery.trim( s.dataType || "*" ).toLowerCase().split( /\s+/ );
 580
 581                 // Determine if a cross-domain request is in order
 582                 if ( ! s.crossDomain ) {
 583                         parts = rurl.exec( s.url.toLowerCase() );
 584                         s.crossDomain = !!(
 585                                         parts &&
 586                                         ( parts[ 1 ] && parts[ 1 ] != loc.protocol ||
 587                                                 parts[ 2 ] != loc.hostname ||
 588                                                 ( parts[ 3 ] || 80 ) != ( loc.port || 80 ) )
 589                         );
 590                 }
 591
 592                 // Convert data if not already a string
 593                 if ( s.data && s.processData && typeof s.data !== "string" ) {
 594                         s.data = jQuery.param( s.data , s.traditional );
 595                 }
 596
 597                 // Apply prefilters
 598                 jQuery.ajaxPrefilter( s , options );
 599
 600                 // Uppercase the type
 601                 s.type = s.type.toUpperCase();
 602
 603                 // Determine if request has content
 604                 s.hasContent = ! rnoContent.test( s.type );
 605
 606                 // Watch for a new set of requests
 607                 if ( s.global && jQuery.active++ === 0 ) {
 608                         jQuery.event.trigger( "ajaxStart" );
 609                 }
 610
 611                 // More options handling for requests with no content
 612                 if ( ! s.hasContent ) {
 613
 614                         // If data is available, append data to url
 615                         if ( s.data ) {
 616                                 s.url += ( rquery.test( s.url ) ? "&" : "?" ) + s.data;
 617                         }
 618
 619                         // Add anti-cache in url if needed
 620                         if ( s.cache === false ) {
 621
 622                                 var ts = jQuery.now(),
 623                                         // try replacing _= if it is there
 624                                         ret = s.url.replace( rts , "$1_=" + ts );
 625
 626                                 // if nothing was replaced, add timestamp to the end
 627                                 s.url = ret + ( (ret == s.url ) ? ( rquery.test( s.url ) ? "&" : "?" ) + "_=" + ts : "");
 628                         }
 629                 }
 630
 631                 // Set the correct header, if data is being sent
 632                 if ( s.data && s.hasContent && s.contentType !== false || options.contentType ) {
 633                         requestHeaders[ "content-type" ] = s.contentType;
 634                 }
 635
 636                 // Set the If-Modified-Since and/or If-None-Match header, if in ifModified mode.
 637                 if ( s.ifModified ) {
 638                         if ( jQuery_lastModified[ s.url ] ) {
 639                                 requestHeaders[ "if-modified-since" ] = jQuery_lastModified[ s.url ];
 640                         }
 641                         if ( jQuery_etag[ s.url ] ) {
 642                                 requestHeaders[ "if-none-match" ] = jQuery_etag[ s.url ];
 643                         }
 644                 }
 645
 646                 // Set the Accepts header for the server, depending on the dataType
 647                 requestHeaders.accept = s.dataTypes[ 0 ] && s.accepts[ s.dataTypes[ 0 ] ] ?
 648                         s.accepts[ s.dataTypes[ 0 ] ] + ( s.dataTypes[ 0 ] !== "*" ? ", */*; q=0.01" : "" ) :
 649                         s.accepts[ "*" ];
 650
 651                 // Check for headers option
 652                 for ( i in s.headers ) {
 653                         requestHeaders[ i.toLowerCase() ] = s.headers[ i ];
 654                 }
 655
 656                 // Allow custom headers/mimetypes and early abort
 657                 if ( s.beforeSend && ( s.beforeSend.call( callbackContext , jXHR , s ) === false || state === 2 ) ) {
 658
 659                                 // Abort if not done already
 660                                 done( 0 , "abort" );
 661
 662                                 // Return false
 663                                 jXHR = false;
 664
 665                 } else {
 666
 667                         // Install callbacks on deferreds
 668                         for ( i in { success:1, error:1, complete:1 } ) {
 669                                 jXHR[ i ]( s[ i ] );
 670                         }
 671
 672                         // Get transport
 673                         transport = jQuery.ajaxTransport( s );
 674
 675                         // If no transport, we auto-abort
 676                         if ( ! transport ) {
 677
 678                                 done( 0 , "notransport" );
 679
 680                         } else {
 681
 682                                 // Set state as sending
 683                                 state = jXHR.readyState = 1;
 684
 685                                 // Send global event
 686                                 if ( s.global ) {
 687                                         globalEventContext.trigger( "ajaxSend" , [ jXHR , s ] );
 688                                 }
 689
 690                                 // Timeout
 691                                 if ( s.async && s.timeout > 0 ) {
 692                                         timeoutTimer = setTimeout(function(){
 693                                                 jXHR.abort( "timeout" );
 694                                         }, s.timeout);
 695                                 }
 696
 697                                 // Try to send
 698                                 try {
 699                                         transport.send(requestHeaders, done);
 700                                 } catch (e) {
 701                                         // Propagate exception as error if not done
 702                                         if ( status === 1 ) {
 703
 704                                                 done(0, "error", "" + e);
 705                                                 jXHR = false;
 706
 707                                         // Simply rethrow otherwise
 708                                         } else {
 709                                                 jQuery.error(e);
 710                                         }
 711                                 }
 712                         }
 713                 }
 714
 715                 return jXHR;
 716         },
 717
 718         // Serialize an array of form elements or a set of
 719         // key/values into a query string
 720         param: function( a, traditional ) {
 721                 var s = [],
 722                         add = function( key, value ) {
 723                                 // If value is a function, invoke it and return its value
 724                                 value = jQuery.isFunction(value) ? value() : value;
 725                                 s[ s.length ] = encodeURIComponent(key) + "=" + encodeURIComponent(value);
 726                         };
 727
 728                 // Set traditional to true for jQuery <= 1.3.2 behavior.
 729                 if ( traditional === undefined ) {
 730                         traditional = jQuery.ajaxSettings.traditional;
 731                 }
 732
 733                 // If an array was passed in, assume that it is an array of form elements.
 734                 if ( jQuery.isArray(a) || a.jquery ) {
 735                         // Serialize the form elements
 736                         jQuery.each( a, function() {
 737                                 add( this.name, this.value );
 738                         });
 739
 740                 } else {
 741                         // If traditional, encode the "old" way (the way 1.3.2 or older
 742                         // did it), otherwise encode params recursively.
 743                         for ( var prefix in a ) {
 744                                 buildParams( prefix, a[prefix], traditional, add );
 745                         }
 746                 }
 747
 748                 // Return the resulting serialization
 749                 return s.join("&").replace(r20, "+");
 750         }
 751 });
 752
 753 function buildParams( prefix, obj, traditional, add ) {
 754         if ( jQuery.isArray(obj) && obj.length ) {
 755                 // Serialize array item.
 756                 jQuery.each( obj, function( i, v ) {
 757                         if ( traditional || rbracket.test( prefix ) ) {
 758                                 // Treat each array item as a scalar.
 759                                 add( prefix, v );
 760
 761                         } else {
 762                                 // If array item is non-scalar (array or object), encode its
 763                                 // numeric index to resolve deserialization ambiguity issues.
 764                                 // Note that rack (as of 1.0.0) can't currently deserialize
 765                                 // nested arrays properly, and attempting to do so may cause
 766                                 // a server error. Possible fixes are to modify rack's
 767                                 // deserialization algorithm or to provide an option or flag
 768                                 // to force array serialization to be shallow.
 769                                 buildParams( prefix + "[" + ( typeof v === "object" || jQuery.isArray(v) ? i : "" ) + "]", v, traditional, add );
 770                         }
 771                 });
 772
 773         } else if ( !traditional && obj != null && typeof obj === "object" ) {
 774                 // If we see an array here, it is empty and should be treated as an empty
 775                 // object
 776                 if ( jQuery.isArray( obj ) || jQuery.isEmptyObject( obj ) ) {
 777                         add( prefix, "" );
 778
 779                 // Serialize object item.
 780                 } else {
 781                         jQuery.each( obj, function( k, v ) {
 782                                 buildParams( prefix + "[" + k + "]", v, traditional, add );
 783                         });
 784                 }
 785
 786         } else {
 787                 // Serialize scalar item.
 788                 add( prefix, obj );
 789         }
 790 }
 791
 792 // This is still on the jQuery object... for now
 793 // Want to move this to jQuery.ajax some day
 794 jQuery.extend({
 795
 796         // Counter for holding the number of active queries
 797         active: 0,
 798
 799         // Last-Modified header cache for next request
 800         lastModified: {},
 801         etag: {}
 802
 803 });
 804
 805 //Execute or select from functions in a given structure of options
 806 function ajax_selectOrExecute( structure , s ) {
 807
 808         var dataTypes = s.dataTypes,
 809                 transportDataType,
 810                 list,
 811                 selected,
 812                 i,
 813                 length,
 814                 checked = {},
 815                 flag,
 816                 noSelect = structure !== "transports";
 817
 818         function initSearch( dataType ) {
 819
 820                 flag = transportDataType !== dataType && ! checked[ dataType ];
 821
 822                 if ( flag ) {
 823
 824                         checked[ dataType ] = 1;
 825                         transportDataType = dataType;
 826                         list = s[ structure ][ dataType ];
 827                         i = -1;
 828                         length = list ? list.length : 0 ;
 829                 }
 830
 831                 return flag;
 832         }
 833
 834         initSearch( dataTypes[ 0 ] );
 835
 836         for ( i = 0 ; ( noSelect || ! selected ) && i <= length ; i++ ) {
 837
 838                 if ( i === length ) {
 839
 840                         initSearch( "*" );
 841
 842                 } else {
 843
 844                         selected = list[ i ]( s , determineDataType );
 845
 846                         // If we got redirected to another dataType
 847                         // Search there (if not in progress or already tried)
 848                         if ( typeof( selected ) === "string" &&
 849                                 initSearch( selected ) ) {
 850
 851                                 dataTypes.unshift( selected );
 852                                 selected = 0;
 853                         }
 854                 }
 855         }
 856
 857         return noSelect ? jQuery : selected;
 858 }
 859
 860 // Add an element to one of the structures in ajaxSettings
 861 function ajax_addElement( structure , args ) {
 862
 863         var i,
 864                 start = 0,
 865                 length = args.length,
 866                 dataTypes = [ "*" ],
 867                 dLength = 1,
 868                 dataType,
 869                 functors = [],
 870                 first,
 871                 append,
 872                 list;
 873
 874         if ( length ) {
 875
 876                 first = jQuery.type( args[ 0 ] );
 877
 878                 if ( first === "object" ) {
 879                         return ajax_selectOrExecute( structure , args[ 0 ] );
 880                 }
 881
 882                 structure = jQuery.ajaxSettings[ structure ];
 883
 884                 if ( first !== "function" ) {
 885
 886                         dataTypes = args[ 0 ].toLowerCase().split(/\s+/);
 887                         dLength = dataTypes.length;
 888                         start = 1;
 889
 890                 }
 891
 892                 if ( dLength && start < length ) {
 893
 894                         functors = sliceFunc.call( args , start );
 895
 896                         for( i = 0 ; i < dLength ; i++ ) {
 897
 898                                 dataType = dataTypes[ i ];
 899
 900                                 first = /^\+/.test( dataType );
 901
 902                                 if (first) {
 903                                         dataType = dataType.substr(1);
 904                                 }
 905
 906                                 if ( dataType !== "" ) {
 907
 908                                         append = Array.prototype[ first ? "unshift" : "push" ];
 909                                         list = structure[ dataType ] = structure[ dataType ] || [];
 910                                         append.apply( list , functors );
 911                                 }
 912                         }
 913                 }
 914         }
 915
 916         return jQuery;
 917 }
 918
 919 // Install prefilter & transport methods
 920 jQuery.each( [ "Prefilter" , "Transport" ] , function( _ , name ) {
 921         _ = name.toLowerCase() + "s";
 922         jQuery[ "ajax" + name ] = function() {
 923                 return ajax_addElement( _ , arguments );
 924         };
 925 } );
 926
 927 // Utility function that handles dataType when response is received
 928 // (for those transports that can give text or xml responses)
 929 function determineDataType( s , ct , text , xml ) {
 930
 931         var contents = s.contents,
 932                 type,
 933                 regexp,
 934                 dataTypes = s.dataTypes,
 935                 transportDataType = dataTypes[0],
 936                 response;
 937
 938         // Auto (xml, json, script or text determined given headers)
 939         if ( transportDataType === "*" ) {
 940
 941                 for ( type in contents ) {
 942                         if ( ( regexp = contents[ type ] ) && regexp.test( ct ) ) {
 943                                 transportDataType = dataTypes[0] = type;
 944                                 break;
 945                         }
 946                 }
 947         }
 948
 949         // xml and parsed as such
 950         if ( transportDataType === "xml" &&
 951                 xml &&
 952                 xml.documentElement /* #4958 */ ) {
 953
 954                 response = xml;
 955
 956         // Text response was provided
 957         } else {
 958
 959                 response = text;
 960
 961                 // If it's not really text, defer to converters
 962                 if ( transportDataType !== "text" ) {
 963                         dataTypes.unshift( "text" );
 964                 }
 965
 966         }
 967
 968         return response;
 969 }
 970
 971 })( jQuery );