src/ajax.js

   1 (function( jQuery ) {
   2
   3 var jsc = jQuery.now(),
   4         rscript = /<script\b[^<]*(?:(?!<\/script>)<[^<]*)*<\/script>/gi,
   5         rselectTextarea = /^(?:select|textarea)/i,
   6         rinput = /^(?:color|date|datetime|email|hidden|month|number|password|range|search|tel|text|time|url|week)$/i,
   7         rnoContent = /^(?:GET|HEAD)$/,
   8         rbracket = /\[\]$/,
   9         jsre = /\=\?(&|$)/,
  10         rquery = /\?/,
  11         rts = /([?&])_=[^&]*/,
  12         rurl = /^(\w+:)?\/\/([^\/?#]+)/,
  13         r20 = /%20/g,
  14         rhash = /#.*$/,
  15
  16         // Keep a copy of the old load method
  17         _load = jQuery.fn.load;
  18
  19 jQuery.fn.extend({
  20         load: function( url, params, callback ) {
  21                 if ( typeof url !== "string" && _load ) {
  22                         return _load.apply( this, arguments );
  23
  24                 // Don't do a request if no elements are being requested
  25                 } else if ( !this.length ) {
  26                         return this;
  27                 }
  28
  29                 var off = url.indexOf(" ");
  30                 if ( off >= 0 ) {
  31                         var selector = url.slice(off, url.length);
  32                         url = url.slice(0, off);
  33                 }
  34
  35                 // Default to a GET request
  36                 var type = "GET";
  37
  38                 // If the second parameter was provided
  39                 if ( params ) {
  40                         // If it's a function
  41                         if ( jQuery.isFunction( params ) ) {
  42                                 // We assume that it's the callback
  43                                 callback = params;
  44                                 params = null;
  45
  46                         // Otherwise, build a param string
  47                         } else if ( typeof params === "object" ) {
  48                                 params = jQuery.param( params, jQuery.ajaxSettings.traditional );
  49                                 type = "POST";
  50                         }
  51                 }
  52
  53                 var self = this;
  54
  55                 // Request the remote document
  56                 jQuery.ajax({
  57                         url: url,
  58                         type: type,
  59                         dataType: "html",
  60                         data: params,
  61                         complete: function( res, status ) {
  62                                 // If successful, inject the HTML into all the matched elements
  63                                 if ( status === "success" || status === "notmodified" ) {
  64                                         // See if a selector was specified
  65                                         self.html( selector ?
  66                                                 // Create a dummy div to hold the results
  67                                                 jQuery("<div>")
  68                                                         // inject the contents of the document in, removing the scripts
  69                                                         // to avoid any 'Permission Denied' errors in IE
  70                                                         .append(res.responseText.replace(rscript, ""))
  71
  72                                                         // Locate the specified elements
  73                                                         .find(selector) :
  74
  75                                                 // If not, just inject the full result
  76                                                 res.responseText );
  77                                 }
  78
  79                                 if ( callback ) {
  80                                         self.each( callback, [res.responseText, status, res] );
  81                                 }
  82                         }
  83                 });
  84
  85                 return this;
  86         },
  87
  88         serialize: function() {
  89                 return jQuery.param(this.serializeArray());
  90         },
  91
  92         serializeArray: function() {
  93                 return this.map(function() {
  94                         return this.elements ? jQuery.makeArray(this.elements) : this;
  95                 })
  96                 .filter(function() {
  97                         return this.name && !this.disabled &&
  98                                 (this.checked || rselectTextarea.test(this.nodeName) ||
  99                                         rinput.test(this.type));
 100                 })
 101                 .map(function( i, elem ) {
 102                         var val = jQuery(this).val();
 103
 104                         return val == null ?
 105                                 null :
 106                                 jQuery.isArray(val) ?
 107                                         jQuery.map( val, function( val, i ) {
 108                                                 return { name: elem.name, value: val };
 109                                         }) :
 110                                         { name: elem.name, value: val };
 111                 }).get();
 112         }
 113 });
 114
 115 // Attach a bunch of functions for handling common AJAX events
 116 jQuery.each( "ajaxStart ajaxStop ajaxComplete ajaxError ajaxSuccess ajaxSend".split(" "), function( i, o ) {
 117         jQuery.fn[o] = function( f ) {
 118                 return this.bind(o, f);
 119         };
 120 });
 121
 122 jQuery.extend({
 123         get: function( url, data, callback, type ) {
 124                 // shift arguments if data argument was omited
 125                 if ( jQuery.isFunction( data ) ) {
 126                         type = type || callback;
 127                         callback = data;
 128                         data = null;
 129                 }
 130
 131                 return jQuery.ajax({
 132                         type: "GET",
 133                         url: url,
 134                         data: data,
 135                         success: callback,
 136                         dataType: type
 137                 });
 138         },
 139
 140         getScript: function( url, callback ) {
 141                 return jQuery.get(url, null, callback, "script");
 142         },
 143
 144         getJSON: function( url, data, callback ) {
 145                 return jQuery.get(url, data, callback, "json");
 146         },
 147
 148         post: function( url, data, callback, type ) {
 149                 // shift arguments if data argument was omited
 150                 if ( jQuery.isFunction( data ) ) {
 151                         type = type || callback;
 152                         callback = data;
 153                         data = {};
 154                 }
 155
 156                 return jQuery.ajax({
 157                         type: "POST",
 158                         url: url,
 159                         data: data,
 160                         success: callback,
 161                         dataType: type
 162                 });
 163         },
 164
 165         ajaxSetup: function( settings ) {
 166                 jQuery.extend( jQuery.ajaxSettings, settings );
 167         },
 168
 169         ajaxSettings: {
 170                 url: location.href,
 171                 global: true,
 172                 type: "GET",
 173                 contentType: "application/x-www-form-urlencoded",
 174                 processData: true,
 175                 async: true,
 176                 /*
 177                 timeout: 0,
 178                 data: null,
 179                 username: null,
 180                 password: null,
 181                 traditional: false,
 182                 */
 183                 // This function can be overriden by calling jQuery.ajaxSetup
 184                 xhr: function() {
 185                         return new window.XMLHttpRequest();
 186                 },
 187                 accepts: {
 188                         xml: "application/xml, text/xml",
 189                         html: "text/html",
 190                         script: "text/javascript, application/javascript",
 191                         json: "application/json, text/javascript",
 192                         text: "text/plain",
 193                         _default: "*/*"
 194                 }
 195         },
 196
 197         ajax: function( origSettings ) {
 198                 // IE8 leaks a lot when we've set abort, and IE6-8 a little
 199                 // when we have set onreadystatechange. Bug #6242
 200                 // XXX IE7 still leaks when abort is called, no matter what
 201                 // we do
 202                 function cleanup() {
 203                         // IE6 will throw an error setting xhr.abort
 204                         try {
 205                                 xhr.abort = xhr.onreadystatechange = jQuery.noop;
 206                         } catch(e) {}
 207                 }
 208
 209                 var s = jQuery.extend(true, {}, jQuery.ajaxSettings, origSettings),
 210                         jsonp, status, data, type = s.type.toUpperCase(), noContent = rnoContent.test(type);
 211
 212                 // toString fixes people passing a window.location or
 213                 // document.location to $.ajax, which worked in 1.4.2 and
 214                 // earlier (bug #7531). It should be removed in 1.5.
 215                 s.url = ("" + s.url).replace( rhash, "" );
 216
 217                 // Use original (not extended) context object if it was provided
 218                 s.context = origSettings && origSettings.context != null ? origSettings.context : s;
 219
 220                 // convert data if not already a string
 221                 if ( s.data && s.processData && typeof s.data !== "string" ) {
 222                         s.data = jQuery.param( s.data, s.traditional );
 223                 }
 224
 225                 // Handle JSONP Parameter Callbacks
 226                 if ( s.dataType === "jsonp" ) {
 227                         if ( type === "GET" ) {
 228                                 if ( !jsre.test( s.url ) ) {
 229                                         s.url += (rquery.test( s.url ) ? "&" : "?") + (s.jsonp || "callback") + "=?";
 230                                 }
 231                         } else if ( !s.data || !jsre.test(s.data) ) {
 232                                 s.data = (s.data ? s.data + "&" : "") + (s.jsonp || "callback") + "=?";
 233                         }
 234                         s.dataType = "json";
 235                 }
 236
 237                 // Build temporary JSONP function
 238                 if ( s.dataType === "json" && (s.data && jsre.test(s.data) || jsre.test(s.url)) ) {
 239                         jsonp = s.jsonpCallback || ("jsonp" + jsc++);
 240
 241                         // Replace the =? sequence both in the query string and the data
 242                         if ( s.data ) {
 243                                 s.data = (s.data + "").replace(jsre, "=" + jsonp + "$1");
 244                         }
 245
 246                         s.url = s.url.replace(jsre, "=" + jsonp + "$1");
 247
 248                         // We need to make sure
 249                         // that a JSONP style response is executed properly
 250                         s.dataType = "script";
 251
 252                         // Handle JSONP-style loading
 253                         var customJsonp = window[ jsonp ];
 254
 255                         window[ jsonp ] = function( tmp ) {
 256                                 if ( jQuery.isFunction( customJsonp ) ) {
 257                                         customJsonp( tmp );
 258
 259                                 } else {
 260                                         // Garbage collect
 261                                         window[ jsonp ] = undefined;
 262
 263                                         try {
 264                                                 delete window[ jsonp ];
 265                                         } catch( jsonpError ) {}
 266                                 }
 267
 268                                 data = tmp;
 269                                 jQuery.handleSuccess( s, xhr, status, data );
 270                                 jQuery.handleComplete( s, xhr, status, data );
 271
 272                                 if ( head ) {
 273                                         head.removeChild( script );
 274                                 }
 275                         };
 276                 }
 277
 278                 if ( s.dataType === "script" && s.cache === undefined ) {
 279                         s.cache = false;
 280                 }
 281
 282                 if ( s.cache === false && noContent ) {
 283                         var ts = jQuery.now();
 284
 285                         // try replacing _= if it is there
 286                         var ret = s.url.replace(rts, "$1_=" + ts);
 287
 288                         // if nothing was replaced, add timestamp to the end
 289                         s.url = ret + ((ret === s.url) ? (rquery.test(s.url) ? "&" : "?") + "_=" + ts : "");
 290                 }
 291
 292                 // If data is available, append data to url for GET/HEAD requests
 293                 if ( s.data && noContent ) {
 294                         s.url += (rquery.test(s.url) ? "&" : "?") + s.data;
 295                 }
 296
 297                 // Watch for a new set of requests
 298                 if ( s.global && jQuery.active++ === 0 ) {
 299                         jQuery.event.trigger( "ajaxStart" );
 300                 }
 301
 302                 // Matches an absolute URL, and saves the domain
 303                 var parts = rurl.exec( s.url ),
 304                         remote = parts && (parts[1] && parts[1].toLowerCase() !== location.protocol || parts[2].toLowerCase() !== location.host);
 305
 306                 // If we're requesting a remote document
 307                 // and trying to load JSON or Script with a GET
 308                 if ( s.dataType === "script" && type === "GET" && remote ) {
 309                         var head = document.getElementsByTagName("head")[0] || document.documentElement;
 310                         var script = document.createElement("script");
 311                         if ( s.scriptCharset ) {
 312                                 script.charset = s.scriptCharset;
 313                         }
 314                         script.src = s.url;
 315
 316                         // Handle Script loading
 317                         if ( !jsonp ) {
 318                                 var done = false;
 319
 320                                 // Attach handlers for all browsers
 321                                 script.onload = script.onreadystatechange = function() {
 322                                         if ( !done && (!this.readyState ||
 323                                                         this.readyState === "loaded" || this.readyState === "complete") ) {
 324                                                 done = true;
 325                                                 jQuery.handleSuccess( s, xhr, status, data );
 326                                                 jQuery.handleComplete( s, xhr, status, data );
 327
 328                                                 // Handle memory leak in IE
 329                                                 script.onload = script.onreadystatechange = null;
 330                                                 if ( head && script.parentNode ) {
 331                                                         head.removeChild( script );
 332                                                 }
 333                                         }
 334                                 };
 335                         }
 336
 337                         // Use insertBefore instead of appendChild  to circumvent an IE6 bug.
 338                         // This arises when a base node is used (#2709 and #4378).
 339                         head.insertBefore( script, head.firstChild );
 340
 341                         // We handle everything using the script element injection
 342                         return undefined;
 343                 }
 344
 345                 var requestDone = false;
 346
 347                 // Create the request object
 348                 var xhr = s.xhr();
 349
 350                 if ( !xhr ) {
 351                         return;
 352                 }
 353
 354                 // Open the socket
 355                 // Passing null username, generates a login popup on Opera (#2865)
 356                 if ( s.username ) {
 357                         xhr.open(type, s.url, s.async, s.username, s.password);
 358                 } else {
 359                         xhr.open(type, s.url, s.async);
 360                 }
 361
 362                 // Need an extra try/catch for cross domain requests in Firefox 3
 363                 try {
 364                         // Set content-type if data specified and content-body is valid for this type
 365                         if ( (s.data != null && !noContent) || (origSettings && origSettings.contentType) ) {
 366                                 xhr.setRequestHeader("Content-Type", s.contentType);
 367                         }
 368
 369                         // Set the If-Modified-Since and/or If-None-Match header, if in ifModified mode.
 370                         if ( s.ifModified ) {
 371                                 if ( jQuery.lastModified[s.url] ) {
 372                                         xhr.setRequestHeader("If-Modified-Since", jQuery.lastModified[s.url]);
 373                                 }
 374
 375                                 if ( jQuery.etag[s.url] ) {
 376                                         xhr.setRequestHeader("If-None-Match", jQuery.etag[s.url]);
 377                                 }
 378                         }
 379
 380                         // Set header so the called script knows that it's an XMLHttpRequest
 381                         // Only send the header if it's not a remote XHR
 382                         if ( !remote ) {
 383                                 xhr.setRequestHeader("X-Requested-With", "XMLHttpRequest");
 384                         }
 385
 386                         // Set the Accepts header for the server, depending on the dataType
 387                         xhr.setRequestHeader("Accept", s.dataType && s.accepts[ s.dataType ] ?
 388                                 s.accepts[ s.dataType ] + ", */*; q=0.01" :
 389                                 s.accepts._default );
 390                 } catch( headerError ) {}
 391
 392                 // Allow custom headers/mimetypes and early abort
 393                 if ( s.beforeSend && s.beforeSend.call(s.context, xhr, s) === false ) {
 394                         // Handle the global AJAX counter
 395                         if ( s.global && jQuery.active-- === 1 ) {
 396                                 jQuery.event.trigger( "ajaxStop" );
 397                         }
 398
 399                         // close opended socket
 400                         xhr.abort();
 401                         return false;
 402                 }
 403
 404                 if ( s.global ) {
 405                         jQuery.triggerGlobal( s, "ajaxSend", [xhr, s] );
 406                 }
 407
 408                 // Wait for a response to come back
 409                 var onreadystatechange = xhr.onreadystatechange = function( isTimeout ) {
 410                         // The request was aborted
 411                         if ( !xhr || xhr.readyState === 0 || isTimeout === "abort" ) {
 412                                 // Opera doesn't call onreadystatechange before this point
 413                                 // so we simulate the call
 414                                 if ( !requestDone ) {
 415                                         jQuery.handleComplete( s, xhr, status, data );
 416                                 }
 417
 418                                 requestDone = true;
 419                                 if ( xhr ) {
 420                                         cleanup();
 421                                 }
 422
 423                         // The transfer is complete and the data is available, or the request timed out
 424                         } else if ( !requestDone && xhr && (xhr.readyState === 4 || isTimeout === "timeout") ) {
 425                                 requestDone = true;
 426
 427                                 status = isTimeout === "timeout" ?
 428                                         "timeout" :
 429                                         !jQuery.httpSuccess( xhr ) ?
 430                                                 "error" :
 431                                                 s.ifModified && jQuery.httpNotModified( xhr, s.url ) ?
 432                                                         "notmodified" :
 433                                                         "success";
 434
 435                                 var errMsg;
 436
 437                                 if ( status === "success" ) {
 438                                         // Watch for, and catch, XML document parse errors
 439                                         try {
 440                                                 // process the data (runs the xml through httpData regardless of callback)
 441                                                 data = jQuery.httpData( xhr, s.dataType, s );
 442                                         } catch( parserError ) {
 443                                                 status = "parsererror";
 444                                                 errMsg = parserError;
 445                                         }
 446                                 }
 447
 448                                 // Make sure that the request was successful or notmodified
 449                                 if ( status === "success" || status === "notmodified" ) {
 450                                         // JSONP handles its own success callback
 451                                         if ( !jsonp ) {
 452                                                 jQuery.handleSuccess( s, xhr, status, data );
 453                                         }
 454                                 } else {
 455                                         jQuery.handleError( s, xhr, status, errMsg );
 456                                 }
 457
 458                                 // Fire the complete handlers
 459                                 if ( !jsonp ) {
 460                                         jQuery.handleComplete( s, xhr, status, data );
 461                                 }
 462
 463                                 if ( isTimeout === "timeout" ) {
 464                                         xhr.abort();
 465                                 }
 466
 467                                 cleanup();
 468                         }
 469                 };
 470
 471                 // Override the abort handler, if we can (IE 6 doesn't allow it, but that's OK)
 472                 // Opera doesn't fire onreadystatechange at all on abort
 473                 try {
 474                         var oldAbort = xhr.abort;
 475                         xhr.abort = function() {
 476                                 if ( xhr ) {
 477                                         // oldAbort has no call property in IE7 so
 478                                         // just do it this way, which works in all
 479                                         // browsers
 480                                         Function.prototype.call.call( oldAbort, xhr );
 481                                 }
 482
 483                                 onreadystatechange( "abort" );
 484                         };
 485                 } catch( abortError ) {}
 486
 487                 // Timeout checker
 488                 if ( s.async && s.timeout > 0 ) {
 489                         setTimeout(function() {
 490                                 // Check to see if the request is still happening
 491                                 if ( xhr && !requestDone ) {
 492                                         onreadystatechange( "timeout" );
 493                                 }
 494                         }, s.timeout);
 495                 }
 496
 497                 // Send the data
 498                 try {
 499                         xhr.send( noContent || s.data == null ? null : s.data );
 500
 501                 } catch( sendError ) {
 502                         jQuery.handleError( s, xhr, null, sendError );
 503
 504                         // Fire the complete handlers
 505                         jQuery.handleComplete( s, xhr, status, data );
 506                 }
 507
 508                 // firefox 1.5 doesn't fire statechange for sync requests
 509                 if ( !s.async ) {
 510                         onreadystatechange();
 511                 }
 512
 513                 // return XMLHttpRequest to allow aborting the request etc.
 514                 return xhr;
 515         },
 516
 517         // Serialize an array of form elements or a set of
 518         // key/values into a query string
 519         param: function( a, traditional ) {
 520                 var s = [],
 521                         add = function( key, value ) {
 522                                 // If value is a function, invoke it and return its value
 523                                 value = jQuery.isFunction(value) ? value() : value;
 524                                 s[ s.length ] = encodeURIComponent(key) + "=" + encodeURIComponent(value);
 525                         };
 526
 527                 // Set traditional to true for jQuery <= 1.3.2 behavior.
 528                 if ( traditional === undefined ) {
 529                         traditional = jQuery.ajaxSettings.traditional;
 530                 }
 531
 532                 // If an array was passed in, assume that it is an array of form elements.
 533                 if ( jQuery.isArray(a) || a.jquery ) {
 534                         // Serialize the form elements
 535                         jQuery.each( a, function() {
 536                                 add( this.name, this.value );
 537                         });
 538
 539                 } else {
 540                         // If traditional, encode the "old" way (the way 1.3.2 or older
 541                         // did it), otherwise encode params recursively.
 542                         for ( var prefix in a ) {
 543                                 buildParams( prefix, a[prefix], traditional, add );
 544                         }
 545                 }
 546
 547                 // Return the resulting serialization
 548                 return s.join("&").replace(r20, "+");
 549         }
 550 });
 551
 552 function buildParams( prefix, obj, traditional, add ) {
 553         if ( jQuery.isArray(obj) && obj.length ) {
 554                 // Serialize array item.
 555                 jQuery.each( obj, function( i, v ) {
 556                         if ( traditional || rbracket.test( prefix ) ) {
 557                                 // Treat each array item as a scalar.
 558                                 add( prefix, v );
 559
 560                         } else {
 561                                 // If array item is non-scalar (array or object), encode its
 562                                 // numeric index to resolve deserialization ambiguity issues.
 563                                 // Note that rack (as of 1.0.0) can't currently deserialize
 564                                 // nested arrays properly, and attempting to do so may cause
 565                                 // a server error. Possible fixes are to modify rack's
 566                                 // deserialization algorithm or to provide an option or flag
 567                                 // to force array serialization to be shallow.
 568                                 buildParams( prefix + "[" + ( typeof v === "object" || jQuery.isArray(v) ? i : "" ) + "]", v, traditional, add );
 569                         }
 570                 });
 571
 572         } else if ( !traditional && obj != null && typeof obj === "object" ) {
 573                 if ( jQuery.isEmptyObject( obj ) ) {
 574                         add( prefix, "" );
 575
 576                 // Serialize object item.
 577                 } else {
 578                         jQuery.each( obj, function( k, v ) {
 579                                 buildParams( prefix + "[" + k + "]", v, traditional, add );
 580                         });
 581                 }
 582
 583         } else {
 584                 // Serialize scalar item.
 585                 add( prefix, obj );
 586         }
 587 }
 588
 589 // This is still on the jQuery object... for now
 590 // Want to move this to jQuery.ajax some day
 591 jQuery.extend({
 592
 593         // Counter for holding the number of active queries
 594         active: 0,
 595
 596         // Last-Modified header cache for next request
 597         lastModified: {},
 598         etag: {},
 599
 600         handleError: function( s, xhr, status, e ) {
 601                 // If a local callback was specified, fire it
 602                 if ( s.error ) {
 603                         s.error.call( s.context, xhr, status, e );
 604                 }
 605
 606                 // Fire the global callback
 607                 if ( s.global ) {
 608                         jQuery.triggerGlobal( s, "ajaxError", [xhr, s, e] );
 609                 }
 610         },
 611
 612         handleSuccess: function( s, xhr, status, data ) {
 613                 // If a local callback was specified, fire it and pass it the data
 614                 if ( s.success ) {
 615                         s.success.call( s.context, data, status, xhr );
 616                 }
 617
 618                 // Fire the global callback
 619                 if ( s.global ) {
 620                         jQuery.triggerGlobal( s, "ajaxSuccess", [xhr, s] );
 621                 }
 622         },
 623
 624         handleComplete: function( s, xhr, status ) {
 625                 // Process result
 626                 if ( s.complete ) {
 627                         s.complete.call( s.context, xhr, status );
 628                 }
 629
 630                 // The request was completed
 631                 if ( s.global ) {
 632                         jQuery.triggerGlobal( s, "ajaxComplete", [xhr, s] );
 633                 }
 634
 635                 // Handle the global AJAX counter
 636                 if ( s.global && jQuery.active-- === 1 ) {
 637                         jQuery.event.trigger( "ajaxStop" );
 638                 }
 639         },
 640
 641         triggerGlobal: function( s, type, args ) {
 642                 (s.context && s.context.url == null ? jQuery(s.context) : jQuery.event).trigger(type, args);
 643         },
 644
 645         // Determines if an XMLHttpRequest was successful or not
 646         httpSuccess: function( xhr ) {
 647                 try {
 648                         // IE error sometimes returns 1223 when it should be 204 so treat it as success, see #1450
 649                         return !xhr.status && location.protocol === "file:" ||
 650                                 xhr.status >= 200 && xhr.status < 300 ||
 651                                 xhr.status === 304 || xhr.status === 1223;
 652                 } catch(e) {}
 653
 654                 return false;
 655         },
 656
 657         // Determines if an XMLHttpRequest returns NotModified
 658         httpNotModified: function( xhr, url ) {
 659                 var lastModified = xhr.getResponseHeader("Last-Modified"),
 660                         etag = xhr.getResponseHeader("Etag");
 661
 662                 if ( lastModified ) {
 663                         jQuery.lastModified[url] = lastModified;
 664                 }
 665
 666                 if ( etag ) {
 667                         jQuery.etag[url] = etag;
 668                 }
 669
 670                 return xhr.status === 304;
 671         },
 672
 673         httpData: function( xhr, type, s ) {
 674                 var ct = xhr.getResponseHeader("content-type") || "",
 675                         xml = type === "xml" || !type && ct.indexOf("xml") >= 0,
 676                         data = xml ? xhr.responseXML : xhr.responseText;
 677
 678                 if ( xml && data.documentElement.nodeName === "parsererror" ) {
 679                         jQuery.error( "parsererror" );
 680                 }
 681
 682                 // Allow a pre-filtering function to sanitize the response
 683                 // s is checked to keep backwards compatibility
 684                 if ( s && s.dataFilter ) {
 685                         data = s.dataFilter( data, type );
 686                 }
 687
 688                 // The filter can actually parse the response
 689                 if ( typeof data === "string" ) {
 690                         // Get the JavaScript object, if JSON is used.
 691                         if ( type === "json" || !type && ct.indexOf("json") >= 0 ) {
 692                                 data = jQuery.parseJSON( data );
 693
 694                         // If the type is "script", eval it in global context
 695                         } else if ( type === "script" || !type && ct.indexOf("javascript") >= 0 ) {
 696                                 jQuery.globalEval( data );
 697                         }
 698                 }
 699
 700                 return data;
 701         }
 702
 703 });
 704
 705 /*
 706  * Create the request object; Microsoft failed to properly
 707  * implement the XMLHttpRequest in IE7 (can't request local files),
 708  * so we use the ActiveXObject when it is available
 709  * Additionally XMLHttpRequest can be disabled in IE7/IE8 so
 710  * we need a fallback.
 711  */
 712 if ( window.ActiveXObject ) {
 713         jQuery.ajaxSettings.xhr = function() {
 714                 if ( window.location.protocol !== "file:" ) {
 715                         try {
 716                                 return new window.XMLHttpRequest();
 717                         } catch(xhrError) {}
 718                 }
 719
 720                 try {
 721                         return new window.ActiveXObject("Microsoft.XMLHTTP");
 722                 } catch(activeError) {}
 723         };
 724 }
 725
 726 // Does this browser support XHR requests?
 727 jQuery.support.ajax = !!jQuery.ajaxSettings.xhr();
 728
 729 })( jQuery );