src/ajax.js

   1 (function( jQuery ) {
   2
   3 var r20 = /%20/g,
   4         rbracket = /\[\]$/,
   5         rCRLF = /\r?\n/g,
   6         rhash = /#.*$/,
   7         rheaders = /^(.*?):\s*(.*?)\r?$/mg, // IE leaves an \r character at EOL
   8         rinput = /^(?:color|date|datetime|email|hidden|month|number|password|range|search|tel|text|time|url|week)$/i,
   9         rnoContent = /^(?:GET|HEAD)$/,
  10         rprotocol = /^\/\//,
  11         rquery = /\?/,
  12         rscript = /<script\b[^<]*(?:(?!<\/script>)<[^<]*)*<\/script>/gi,
  13         rselectTextarea = /^(?:select|textarea)/i,
  14         rspacesAjax = /\s+/,
  15         rts = /([?&])_=[^&]*/,
  16         rurl = /^(\w+:)\/\/([^\/?#:]+)(?::(\d+))?/,
  17
  18         // Keep a copy of the old load method
  19         _load = jQuery.fn.load,
  20
  21         /* Prefilters
  22          * 1) They are useful to introduce custom dataTypes (see ajax/jsonp.js for an example)
  23          * 2) These are called:
  24          *    - BEFORE asking for a transport
  25          *    - AFTER param serialization (s.data is a string if s.processData is true)
  26          * 3) key is the dataType
  27          * 4) the catchall symbol "*" can be used
  28          * 5) execution will start with transport dataType and THEN continue down to "*" if needed
  29          */
  30         prefilters = {},
  31
  32         /* Transports bindings
  33          * 1) key is the dataType
  34          * 2) the catchall symbol "*" can be used
  35          * 3) selection will start with transport dataType and THEN go to "*" if needed
  36          */
  37         transports = {};
  38
  39 // Base "constructor" for jQuery.ajaxPrefilter and jQuery.ajaxTransport
  40 function addToPrefiltersOrTransports( structure ) {
  41
  42         // dataTypeExpression is optional and defaults to "*"
  43         return function( dataTypeExpression, func ) {
  44
  45                 if ( typeof dataTypeExpression !== "string" ) {
  46                         func = dataTypeExpression;
  47                         dataTypeExpression = "*";
  48                 }
  49
  50                 if ( jQuery.isFunction( func ) ) {
  51                         var dataTypes = dataTypeExpression.toLowerCase().split( rspacesAjax ),
  52                                 i = 0,
  53                                 length = dataTypes.length,
  54                                 dataType,
  55                                 list,
  56                                 placeBefore;
  57
  58                         // For each dataType in the dataTypeExpression
  59                         for(; i < length; i++ ) {
  60                                 dataType = dataTypes[ i ];
  61                                 // We control if we're asked to add before
  62                                 // any existing element
  63                                 placeBefore = /^\+/.test( dataType );
  64                                 if ( placeBefore ) {
  65                                         dataType = dataType.substr( 1 ) || "*";
  66                                 }
  67                                 list = structure[ dataType ] = structure[ dataType ] || [];
  68                                 // then we add to the structure accordingly
  69                                 list[ placeBefore ? "unshift" : "push" ]( func );
  70                         }
  71                 }
  72         };
  73 }
  74
  75 //Base inspection function for prefilters and transports
  76 function inspectPrefiltersOrTransports( structure, options, originalOptions, jXHR,
  77                 dataType /* internal */, inspected /* internal */ ) {
  78
  79         dataType = dataType || options.dataTypes[ 0 ];
  80         inspected = inspected || {};
  81
  82         inspected[ dataType ] = true;
  83
  84         var list = structure[ dataType ],
  85                 i = 0,
  86                 length = list ? list.length : 0,
  87                 executeOnly = ( structure === prefilters ),
  88                 selection;
  89
  90         for(; i < length && ( executeOnly || !selection ); i++ ) {
  91                 selection = list[ i ]( options, originalOptions, jXHR );
  92                 // If we got redirected to another dataType
  93                 // we try there if not done already
  94                 if ( typeof selection === "string" ) {
  95                         if ( inspected[ selection ] ) {
  96                                 selection = undefined;
  97                         } else {
  98                                 options.dataTypes.unshift( selection );
  99                                 selection = inspectPrefiltersOrTransports(
 100                                                 structure, options, originalOptions, jXHR, selection, inspected );
 101                         }
 102                 }
 103         }
 104         // If we're only executing or nothing was selected
 105         // we try the catchall dataType if not done already
 106         if ( ( executeOnly || !selection ) && !inspected[ "*" ] ) {
 107                 selection = inspectPrefiltersOrTransports(
 108                                 structure, options, originalOptions, jXHR, "*", inspected );
 109         }
 110         // unnecessary when only executing (prefilters)
 111         // but it'll be ignored by the caller in that case
 112         return selection;
 113 }
 114
 115 jQuery.fn.extend({
 116         load: function( url, params, callback ) {
 117                 if ( typeof url !== "string" && _load ) {
 118                         return _load.apply( this, arguments );
 119
 120                 // Don't do a request if no elements are being requested
 121                 } else if ( !this.length ) {
 122                         return this;
 123                 }
 124
 125                 var off = url.indexOf( " " );
 126                 if ( off >= 0 ) {
 127                         var selector = url.slice( off, url.length );
 128                         url = url.slice( 0, off );
 129                 }
 130
 131                 // Default to a GET request
 132                 var type = "GET";
 133
 134                 // If the second parameter was provided
 135                 if ( params ) {
 136                         // If it's a function
 137                         if ( jQuery.isFunction( params ) ) {
 138                                 // We assume that it's the callback
 139                                 callback = params;
 140                                 params = null;
 141
 142                         // Otherwise, build a param string
 143                         } else if ( typeof params === "object" ) {
 144                                 params = jQuery.param( params, jQuery.ajaxSettings.traditional );
 145                                 type = "POST";
 146                         }
 147                 }
 148
 149                 var self = this;
 150
 151                 // Request the remote document
 152                 jQuery.ajax({
 153                         url: url,
 154                         type: type,
 155                         dataType: "html",
 156                         data: params,
 157                         // Complete callback (responseText is used internally)
 158                         complete: function( jXHR, status, responseText ) {
 159                                 // Store the response as specified by the jXHR object
 160                                 responseText = jXHR.responseText;
 161                                 // If successful, inject the HTML into all the matched elements
 162                                 if ( jXHR.isResolved() ) {
 163                                         // #4825: Get the actual response in case
 164                                         // a dataFilter is present in ajaxSettings
 165                                         jXHR.done(function( r ) {
 166                                                 responseText = r;
 167                                         });
 168                                         // See if a selector was specified
 169                                         self.html( selector ?
 170                                                 // Create a dummy div to hold the results
 171                                                 jQuery("<div>")
 172                                                         // inject the contents of the document in, removing the scripts
 173                                                         // to avoid any 'Permission Denied' errors in IE
 174                                                         .append(responseText.replace(rscript, ""))
 175
 176                                                         // Locate the specified elements
 177                                                         .find(selector) :
 178
 179                                                 // If not, just inject the full result
 180                                                 responseText );
 181                                 }
 182
 183                                 if ( callback ) {
 184                                         self.each( callback, [ responseText, status, jXHR ] );
 185                                 }
 186                         }
 187                 });
 188
 189                 return this;
 190         },
 191
 192         serialize: function() {
 193                 return jQuery.param( this.serializeArray() );
 194         },
 195
 196         serializeArray: function() {
 197                 return this.map(function(){
 198                         return this.elements ? jQuery.makeArray( this.elements ) : this;
 199                 })
 200                 .filter(function(){
 201                         return this.name && !this.disabled &&
 202                                 ( this.checked || rselectTextarea.test( this.nodeName ) ||
 203                                         rinput.test( this.type ) );
 204                 })
 205                 .map(function( i, elem ){
 206                         var val = jQuery( this ).val();
 207
 208                         return val == null ?
 209                                 null :
 210                                 jQuery.isArray( val ) ?
 211                                         jQuery.map( val, function( val, i ){
 212                                                 return { name: elem.name, value: val.replace( rCRLF, "\r\n" ) };
 213                                         }) :
 214                                         { name: elem.name, value: val.replace( rCRLF, "\r\n" ) };
 215                 }).get();
 216         }
 217 });
 218
 219 // Attach a bunch of functions for handling common AJAX events
 220 jQuery.each( "ajaxStart ajaxStop ajaxComplete ajaxError ajaxSuccess ajaxSend".split( " " ), function( i, o ){
 221         jQuery.fn[ o ] = function( f ){
 222                 return this.bind( o, f );
 223         };
 224 } );
 225
 226 jQuery.each( [ "get", "post" ], function( i, method ) {
 227         jQuery[ method ] = function( url, data, callback, type ) {
 228                 // shift arguments if data argument was omitted
 229                 if ( jQuery.isFunction( data ) ) {
 230                         type = type || callback;
 231                         callback = data;
 232                         data = null;
 233                 }
 234
 235                 return jQuery.ajax({
 236                         type: method,
 237                         url: url,
 238                         data: data,
 239                         success: callback,
 240                         dataType: type
 241                 });
 242         };
 243 } );
 244
 245 jQuery.extend({
 246
 247         getScript: function( url, callback ) {
 248                 return jQuery.get( url, null, callback, "script" );
 249         },
 250
 251         getJSON: function( url, data, callback ) {
 252                 return jQuery.get( url, data, callback, "json" );
 253         },
 254
 255         ajaxSetup: function( settings ) {
 256                 jQuery.extend( true, jQuery.ajaxSettings, settings );
 257                 if ( settings.context ) {
 258                         jQuery.ajaxSettings.context = settings.context;
 259                 }
 260         },
 261
 262         ajaxSettings: {
 263                 url: location.href,
 264                 global: true,
 265                 type: "GET",
 266                 contentType: "application/x-www-form-urlencoded",
 267                 processData: true,
 268                 async: true,
 269                 /*
 270                 timeout: 0,
 271                 data: null,
 272                 dataType: null,
 273                 username: null,
 274                 password: null,
 275                 cache: null,
 276                 traditional: false,
 277                 headers: {},
 278                 crossDomain: null,
 279                 */
 280
 281                 accepts: {
 282                         xml: "application/xml, text/xml",
 283                         html: "text/html",
 284                         text: "text/plain",
 285                         json: "application/json, text/javascript",
 286                         "*": "*/*"
 287                 },
 288
 289                 contents: {
 290                         xml: /xml/,
 291                         html: /html/,
 292                         json: /json/
 293                 },
 294
 295                 responseFields: {
 296                         xml: "responseXML",
 297                         text: "responseText"
 298                 },
 299
 300                 // List of data converters
 301                 // 1) key format is "source_type destination_type" (a single space in-between)
 302                 // 2) the catchall symbol "*" can be used for source_type
 303                 converters: {
 304
 305                         // Convert anything to text
 306                         "* text": window.String,
 307
 308                         // Text to html (true = no transformation)
 309                         "text html": true,
 310
 311                         // Evaluate text as a json expression
 312                         "text json": jQuery.parseJSON,
 313
 314                         // Parse text as xml
 315                         "text xml": jQuery.parseXML
 316                 }
 317         },
 318
 319         ajaxPrefilter: addToPrefiltersOrTransports( prefilters ),
 320         ajaxTransport: addToPrefiltersOrTransports( transports ),
 321
 322         // Main method
 323         ajax: function( url, options ) {
 324
 325                 // If options is not an object,
 326                 // we simulate pre-1.5 signature
 327                 if ( typeof options !== "object" ) {
 328                         options = url;
 329                         url = undefined;
 330                 }
 331
 332                 // Force options to be an object
 333                 options = options || {};
 334
 335                 var // Create the final options object
 336                         s = jQuery.extend( true, {}, jQuery.ajaxSettings, options ),
 337                         // Callbacks context
 338                         // We force the original context if it exists
 339                         // or take it from jQuery.ajaxSettings otherwise
 340                         // (plain objects used as context get extended)
 341                         callbackContext =
 342                                 ( s.context = ( "context" in options ? options : jQuery.ajaxSettings ).context ) || s,
 343                         // Context for global events
 344                         // It's the callbackContext if one was provided in the options
 345                         // and if it's a DOM node
 346                         globalEventContext = callbackContext !== s && callbackContext.nodeType ?
 347                                 jQuery( callbackContext ) : jQuery.event,
 348                         // Deferreds
 349                         deferred = jQuery.Deferred(),
 350                         completeDeferred = jQuery._Deferred(),
 351                         // Status-dependent callbacks
 352                         statusCode = s.statusCode || {},
 353                         // Headers (they are sent all at once)
 354                         requestHeaders = {},
 355                         // Response headers
 356                         responseHeadersString,
 357                         responseHeaders,
 358                         // transport
 359                         transport,
 360                         // timeout handle
 361                         timeoutTimer,
 362                         // Cross-domain detection vars
 363                         loc = document.location,
 364                         protocol = loc.protocol || "http:",
 365                         parts,
 366                         // The jXHR state
 367                         state = 0,
 368                         // Loop variable
 369                         i,
 370                         // Fake xhr
 371                         jXHR = {
 372
 373                                 readyState: 0,
 374
 375                                 // Caches the header
 376                                 setRequestHeader: function( name, value ) {
 377                                         if ( state === 0 ) {
 378                                                 requestHeaders[ name.toLowerCase() ] = value;
 379                                         }
 380                                         return this;
 381                                 },
 382
 383                                 // Raw string
 384                                 getAllResponseHeaders: function() {
 385                                         return state === 2 ? responseHeadersString : null;
 386                                 },
 387
 388                                 // Builds headers hashtable if needed
 389                                 getResponseHeader: function( key ) {
 390                                         var match;
 391                                         if ( state === 2 ) {
 392                                                 if ( !responseHeaders ) {
 393                                                         responseHeaders = {};
 394                                                         while( ( match = rheaders.exec( responseHeadersString ) ) ) {
 395                                                                 responseHeaders[ match[1].toLowerCase() ] = match[ 2 ];
 396                                                         }
 397                                                 }
 398                                                 match = responseHeaders[ key.toLowerCase() ];
 399                                         }
 400                                         return match || null;
 401                                 },
 402
 403                                 // Cancel the request
 404                                 abort: function( statusText ) {
 405                                         statusText = statusText || "abort";
 406                                         if ( transport ) {
 407                                                 transport.abort( statusText );
 408                                         }
 409                                         done( 0, statusText );
 410                                         return this;
 411                                 }
 412                         };
 413
 414                 // Callback for when everything is done
 415                 // It is defined here because jslint complains if it is declared
 416                 // at the end of the function (which would be more logical and readable)
 417                 function done( status, statusText, responses, headers) {
 418
 419                         // Called once
 420                         if ( state === 2 ) {
 421                                 return;
 422                         }
 423
 424                         // State is "done" now
 425                         state = 2;
 426
 427                         // Clear timeout if it exists
 428                         if ( timeoutTimer ) {
 429                                 clearTimeout( timeoutTimer );
 430                         }
 431
 432                         // Dereference transport for early garbage collection
 433                         // (no matter how long the jXHR object will be used)
 434                         transport = undefined;
 435
 436                         // Cache response headers
 437                         responseHeadersString = headers || "";
 438
 439                         // Set readyState
 440                         jXHR.readyState = status ? 4 : 0;
 441
 442                         var isSuccess,
 443                                 success,
 444                                 error,
 445                                 response = responses ? ajaxHandleResponses( s, jXHR, responses ) : undefined,
 446                                 lastModified,
 447                                 etag;
 448
 449                         // If successful, handle type chaining
 450                         if ( status >= 200 && status < 300 || status === 304 ) {
 451
 452                                 // Set the If-Modified-Since and/or If-None-Match header, if in ifModified mode.
 453                                 if ( s.ifModified ) {
 454
 455                                         if ( ( lastModified = jXHR.getResponseHeader( "Last-Modified" ) ) ) {
 456                                                 jQuery.lastModified[ s.url ] = lastModified;
 457                                         }
 458                                         if ( ( etag = jXHR.getResponseHeader( "Etag" ) ) ) {
 459                                                 jQuery.etag[ s.url ] = etag;
 460                                         }
 461                                 }
 462
 463                                 // If not modified
 464                                 if ( status === 304 ) {
 465
 466                                         statusText = "notmodified";
 467                                         isSuccess = true;
 468
 469                                 // If we have data
 470                                 } else {
 471
 472                                         try {
 473                                                 success = ajaxConvert( s, response );
 474                                                 statusText = "success";
 475                                                 isSuccess = true;
 476                                         } catch(e) {
 477                                                 // We have a parsererror
 478                                                 statusText = "parsererror";
 479                                                 error = e;
 480                                         }
 481                                 }
 482                         } else {
 483                                 // We extract error from statusText
 484                                 // then normalize statusText and status for non-aborts
 485                                 error = statusText;
 486                                 if( status ) {
 487                                         statusText = "error";
 488                                         if ( status < 0 ) {
 489                                                 status = 0;
 490                                         }
 491                                 }
 492                         }
 493
 494                         // Set data for the fake xhr object
 495                         jXHR.status = status;
 496                         jXHR.statusText = statusText;
 497
 498                         // Success/Error
 499                         if ( isSuccess ) {
 500                                 deferred.resolveWith( callbackContext, [ success, statusText, jXHR ] );
 501                         } else {
 502                                 deferred.rejectWith( callbackContext, [ jXHR, statusText, error ] );
 503                         }
 504
 505                         // Status-dependent callbacks
 506                         jXHR.statusCode( statusCode );
 507                         statusCode = undefined;
 508
 509                         if ( s.global ) {
 510                                 globalEventContext.trigger( "ajax" + ( isSuccess ? "Success" : "Error" ),
 511                                                 [ jXHR, s, isSuccess ? success : error ] );
 512                         }
 513
 514                         // Complete
 515                         completeDeferred.resolveWith( callbackContext, [ jXHR, statusText ] );
 516
 517                         if ( s.global ) {
 518                                 globalEventContext.trigger( "ajaxComplete", [ jXHR, s] );
 519                                 // Handle the global AJAX counter
 520                                 if ( !( --jQuery.active ) ) {
 521                                         jQuery.event.trigger( "ajaxStop" );
 522                                 }
 523                         }
 524                 }
 525
 526                 // Attach deferreds
 527                 deferred.promise( jXHR );
 528                 jXHR.success = jXHR.done;
 529                 jXHR.error = jXHR.fail;
 530                 jXHR.complete = completeDeferred.done;
 531
 532                 // Status-dependent callbacks
 533                 jXHR.statusCode = function( map ) {
 534                         if ( map ) {
 535                                 var tmp;
 536                                 if ( state < 2 ) {
 537                                         for( tmp in map ) {
 538                                                 statusCode[ tmp ] = [ statusCode[tmp], map[tmp] ];
 539                                         }
 540                                 } else {
 541                                         tmp = map[ jXHR.status ];
 542                                         jXHR.then( tmp, tmp );
 543                                 }
 544                         }
 545                         return this;
 546                 };
 547
 548                 // Remove hash character (#7531: and string promotion)
 549                 // Add protocol if not provided (#5866: IE7 issue with protocol-less urls)
 550                 // We also use the url parameter if available
 551                 s.url = ( "" + ( url || s.url ) ).replace( rhash, "" ).replace( rprotocol, protocol + "//" );
 552
 553                 // Extract dataTypes list
 554                 s.dataTypes = jQuery.trim( s.dataType || "*" ).toLowerCase().split( rspacesAjax );
 555
 556                 // Determine if a cross-domain request is in order
 557                 if ( !s.crossDomain ) {
 558                         parts = rurl.exec( s.url.toLowerCase() );
 559                         s.crossDomain = !!( parts &&
 560                                 ( parts[ 1 ] != protocol || parts[ 2 ] != loc.hostname ||
 561                                         ( parts[ 3 ] || ( parts[ 1 ] === "http:" ? 80 : 443 ) ) !=
 562                                                 ( loc.port || ( protocol === "http:" ? 80 : 443 ) ) )
 563                         );
 564                 }
 565
 566                 // Convert data if not already a string
 567                 if ( s.data && s.processData && typeof s.data !== "string" ) {
 568                         s.data = jQuery.param( s.data, s.traditional );
 569                 }
 570
 571                 // Apply prefilters
 572                 inspectPrefiltersOrTransports( prefilters, s, options, jXHR );
 573
 574                 // Uppercase the type
 575                 s.type = s.type.toUpperCase();
 576
 577                 // Determine if request has content
 578                 s.hasContent = !rnoContent.test( s.type );
 579
 580                 // Watch for a new set of requests
 581                 if ( s.global && jQuery.active++ === 0 ) {
 582                         jQuery.event.trigger( "ajaxStart" );
 583                 }
 584
 585                 // More options handling for requests with no content
 586                 if ( !s.hasContent ) {
 587
 588                         // If data is available, append data to url
 589                         if ( s.data ) {
 590                                 s.url += ( rquery.test( s.url ) ? "&" : "?" ) + s.data;
 591                         }
 592
 593                         // Add anti-cache in url if needed
 594                         if ( s.cache === false ) {
 595
 596                                 var ts = jQuery.now(),
 597                                         // try replacing _= if it is there
 598                                         ret = s.url.replace( rts, "$1_=" + ts );
 599
 600                                 // if nothing was replaced, add timestamp to the end
 601                                 s.url = ret + ( (ret === s.url ) ? ( rquery.test( s.url ) ? "&" : "?" ) + "_=" + ts : "" );
 602                         }
 603                 }
 604
 605                 // Set the correct header, if data is being sent
 606                 if ( s.data && s.hasContent && s.contentType !== false || options.contentType ) {
 607                         requestHeaders[ "content-type" ] = s.contentType;
 608                 }
 609
 610                 // Set the If-Modified-Since and/or If-None-Match header, if in ifModified mode.
 611                 if ( s.ifModified ) {
 612                         if ( jQuery.lastModified[ s.url ] ) {
 613                                 requestHeaders[ "if-modified-since" ] = jQuery.lastModified[ s.url ];
 614                         }
 615                         if ( jQuery.etag[ s.url ] ) {
 616                                 requestHeaders[ "if-none-match" ] = jQuery.etag[ s.url ];
 617                         }
 618                 }
 619
 620                 // Set the Accepts header for the server, depending on the dataType
 621                 requestHeaders.accept = s.dataTypes[ 0 ] && s.accepts[ s.dataTypes[0] ] ?
 622                         s.accepts[ s.dataTypes[0] ] + ( s.dataTypes[ 0 ] !== "*" ? ", */*; q=0.01" : "" ) :
 623                         s.accepts[ "*" ];
 624
 625                 // Check for headers option
 626                 for ( i in s.headers ) {
 627                         requestHeaders[ i.toLowerCase() ] = s.headers[ i ];
 628                 }
 629
 630                 // Allow custom headers/mimetypes and early abort
 631                 if ( s.beforeSend && ( s.beforeSend.call( callbackContext, jXHR, s ) === false || state === 2 ) ) {
 632                                 // Abort if not done already
 633                                 done( 0, "abort" );
 634                                 // Return false
 635                                 jXHR = false;
 636
 637                 } else {
 638
 639                         // Install callbacks on deferreds
 640                         for ( i in { success: 1, error: 1, complete: 1 } ) {
 641                                 jXHR[ i ]( s[ i ] );
 642                         }
 643
 644                         // Get transport
 645                         transport = inspectPrefiltersOrTransports( transports, s, options, jXHR );
 646
 647                         // If no transport, we auto-abort
 648                         if ( !transport ) {
 649                                 done( -1, "No Transport" );
 650                         } else {
 651                                 // Set state as sending
 652                                 state = jXHR.readyState = 1;
 653                                 // Send global event
 654                                 if ( s.global ) {
 655                                         globalEventContext.trigger( "ajaxSend", [ jXHR, s ] );
 656                                 }
 657                                 // Timeout
 658                                 if ( s.async && s.timeout > 0 ) {
 659                                         timeoutTimer = setTimeout( function(){
 660                                                 jXHR.abort( "timeout" );
 661                                         }, s.timeout );
 662                                 }
 663
 664                                 try {
 665                                         transport.send( requestHeaders, done );
 666                                 } catch (e) {
 667                                         // Propagate exception as error if not done
 668                                         if ( status < 2 ) {
 669                                                 done( -1, e );
 670                                         // Simply rethrow otherwise
 671                                         } else {
 672                                                 jQuery.error( e );
 673                                         }
 674                                 }
 675                         }
 676                 }
 677                 return jXHR;
 678         },
 679
 680         // Serialize an array of form elements or a set of
 681         // key/values into a query string
 682         param: function( a, traditional ) {
 683                 var s = [],
 684                         add = function( key, value ) {
 685                                 // If value is a function, invoke it and return its value
 686                                 value = jQuery.isFunction( value ) ? value() : value;
 687                                 s[ s.length ] = encodeURIComponent( key ) + "=" + encodeURIComponent( value );
 688                         };
 689
 690                 // Set traditional to true for jQuery <= 1.3.2 behavior.
 691                 if ( traditional === undefined ) {
 692                         traditional = jQuery.ajaxSettings.traditional;
 693                 }
 694
 695                 // If an array was passed in, assume that it is an array of form elements.
 696                 if ( jQuery.isArray( a ) || a.jquery ) {
 697                         // Serialize the form elements
 698                         jQuery.each( a, function() {
 699                                 add( this.name, this.value );
 700                         } );
 701
 702                 } else {
 703                         // If traditional, encode the "old" way (the way 1.3.2 or older
 704                         // did it), otherwise encode params recursively.
 705                         for ( var prefix in a ) {
 706                                 buildParams( prefix, a[ prefix ], traditional, add );
 707                         }
 708                 }
 709
 710                 // Return the resulting serialization
 711                 return s.join( "&" ).replace( r20, "+" );
 712         }
 713 });
 714
 715 function buildParams( prefix, obj, traditional, add ) {
 716         if ( jQuery.isArray( obj ) && obj.length ) {
 717                 // Serialize array item.
 718                 jQuery.each( obj, function( i, v ) {
 719                         if ( traditional || rbracket.test( prefix ) ) {
 720                                 // Treat each array item as a scalar.
 721                                 add( prefix, v );
 722
 723                         } else {
 724                                 // If array item is non-scalar (array or object), encode its
 725                                 // numeric index to resolve deserialization ambiguity issues.
 726                                 // Note that rack (as of 1.0.0) can't currently deserialize
 727                                 // nested arrays properly, and attempting to do so may cause
 728                                 // a server error. Possible fixes are to modify rack's
 729                                 // deserialization algorithm or to provide an option or flag
 730                                 // to force array serialization to be shallow.
 731                                 buildParams( prefix + "[" + ( typeof v === "object" || jQuery.isArray(v) ? i : "" ) + "]", v, traditional, add );
 732                         }
 733                 });
 734
 735         } else if ( !traditional && obj != null && typeof obj === "object" ) {
 736                 // If we see an array here, it is empty and should be treated as an empty
 737                 // object
 738                 if ( jQuery.isArray( obj ) || jQuery.isEmptyObject( obj ) ) {
 739                         add( prefix, "" );
 740
 741                 // Serialize object item.
 742                 } else {
 743                         for ( var name in obj ) {
 744                                 buildParams( prefix + "[" + name + "]", obj[ name ], traditional, add );
 745                         }
 746                 }
 747
 748         } else {
 749                 // Serialize scalar item.
 750                 add( prefix, obj );
 751         }
 752 }
 753
 754 // This is still on the jQuery object... for now
 755 // Want to move this to jQuery.ajax some day
 756 jQuery.extend({
 757
 758         // Counter for holding the number of active queries
 759         active: 0,
 760
 761         // Last-Modified header cache for next request
 762         lastModified: {},
 763         etag: {}
 764
 765 });
 766
 767 /* Handles responses to an ajax request:
 768  * - sets all responseXXX fields accordingly
 769  * - finds the right dataType (mediates between content-type and expected dataType)
 770  * - returns the corresponding response
 771  */
 772 function ajaxHandleResponses( s, jXHR, responses ) {
 773
 774         var contents = s.contents,
 775                 dataTypes = s.dataTypes,
 776                 responseFields = s.responseFields,
 777                 ct,
 778                 type,
 779                 finalDataType,
 780                 firstDataType;
 781
 782         // Fill responseXXX fields
 783         for( type in responseFields ) {
 784                 if ( type in responses ) {
 785                         jXHR[ responseFields[type] ] = responses[ type ];
 786                 }
 787         }
 788
 789         // Remove auto dataType and get content-type in the process
 790         while( dataTypes[ 0 ] === "*" ) {
 791                 dataTypes.shift();
 792                 if ( ct === undefined ) {
 793                         ct = jXHR.getResponseHeader( "content-type" );
 794                 }
 795         }
 796
 797         // Check if we're dealing with a known content-type
 798         if ( ct ) {
 799                 for ( type in contents ) {
 800                         if ( contents[ type ] && contents[ type ].test( ct ) ) {
 801                                 dataTypes.unshift( type );
 802                                 break;
 803                         }
 804                 }
 805         }
 806
 807         // Check to see if we have a response for the expected dataType
 808         if ( dataTypes[ 0 ] in responses ) {
 809                 finalDataType = dataTypes[ 0 ];
 810         } else {
 811                 // Try convertible dataTypes
 812                 for ( type in responses ) {
 813                         if ( !dataTypes[ 0 ] || s.converters[ type + " " + dataTypes[0] ] ) {
 814                                 finalDataType = type;
 815                                 break;
 816                         }
 817                         if ( !firstDataType ) {
 818                                 firstDataType = type;
 819                         }
 820                 }
 821                 // Or just use first one
 822                 finalDataType = finalDataType || firstDataType;
 823         }
 824
 825         // If we found a dataType
 826         // We add the dataType to the list if needed
 827         // and return the corresponding response
 828         if ( finalDataType ) {
 829                 if ( finalDataType !== dataTypes[ 0 ] ) {
 830                         dataTypes.unshift( finalDataType );
 831                 }
 832                 return responses[ finalDataType ];
 833         }
 834 }
 835
 836 // Chain conversions given the request and the original response
 837 function ajaxConvert( s, response ) {
 838
 839         // Apply the dataFilter if provided
 840         if ( s.dataFilter ) {
 841                 response = s.dataFilter( response, s.dataType );
 842         }
 843
 844         var dataTypes = s.dataTypes,
 845                 converters = {},
 846                 i,
 847                 key,
 848                 length = dataTypes.length,
 849                 tmp,
 850                 // Current and previous dataTypes
 851                 current = dataTypes[ 0 ],
 852                 prev,
 853                 // Conversion expression
 854                 conversion,
 855                 // Conversion function
 856                 conv,
 857                 // Conversion functions (transitive conversion)
 858                 conv1,
 859                 conv2;
 860
 861         // For each dataType in the chain
 862         for( i = 1; i < length; i++ ) {
 863
 864                 // Create converters map
 865                 // with lowercased keys
 866                 if ( i === 1 ) {
 867                         for( key in s.converters ) {
 868                                 if( typeof key === "string" ) {
 869                                         converters[ key.toLowerCase() ] = s.converters[ key ];
 870                                 }
 871                         }
 872                 }
 873
 874                 // Get the dataTypes
 875                 prev = current;
 876                 current = dataTypes[ i ];
 877
 878                 // If current is auto dataType, update it to prev
 879                 if( current === "*" ) {
 880                         current = prev;
 881                 // If no auto and dataTypes are actually different
 882                 } else if ( prev !== "*" && prev !== current ) {
 883
 884                         // Get the converter
 885                         conversion = prev + " " + current;
 886                         conv = converters[ conversion ] || converters[ "* " + current ];
 887
 888                         // If there is no direct converter, search transitively
 889                         if ( !conv ) {
 890                                 conv2 = undefined;
 891                                 for( conv1 in converters ) {
 892                                         tmp = conv1.split( " " );
 893                                         if ( tmp[ 0 ] === prev || tmp[ 0 ] === "*" ) {
 894                                                 conv2 = converters[ tmp[1] + " " + current ];
 895                                                 if ( conv2 ) {
 896                                                         conv1 = converters[ conv1 ];
 897                                                         if ( conv1 === true ) {
 898                                                                 conv = conv2;
 899                                                         } else if ( conv2 === true ) {
 900                                                                 conv = conv1;
 901                                                         }
 902                                                         break;
 903                                                 }
 904                                         }
 905                                 }
 906                         }
 907                         // If we found no converter, dispatch an error
 908                         if ( !( conv || conv2 ) ) {
 909                                 jQuery.error( "No conversion from " + conversion.replace(" "," to ") );
 910                         }
 911                         // If found converter is not an equivalence
 912                         if ( conv !== true ) {
 913                                 // Convert with 1 or 2 converters accordingly
 914                                 response = conv ? conv( response ) : conv2( conv1(response) );
 915                         }
 916                 }
 917         }
 918         return response;
 919 }
 920
 921 })( jQuery );