js/pz2.js

   1 /*
   2 ** pz2.js - pazpar2's javascript client library.
   3 */
   4
   5 //since explorer is flawed
   6 if (!window['Node']) {
   7     window.Node = new Object();
   8     Node.ELEMENT_NODE = 1;
   9     Node.ATTRIBUTE_NODE = 2;
  10     Node.TEXT_NODE = 3;
  11     Node.CDATA_SECTION_NODE = 4;
  12     Node.ENTITY_REFERENCE_NODE = 5;
  13     Node.ENTITY_NODE = 6;
  14     Node.PROCESSING_INSTRUCTION_NODE = 7;
  15     Node.COMMENT_NODE = 8;
  16     Node.DOCUMENT_NODE = 9;
  17     Node.DOCUMENT_TYPE_NODE = 10;
  18     Node.DOCUMENT_FRAGMENT_NODE = 11;
  19     Node.NOTATION_NODE = 12;
  20 }
  21
  22 // prevent execution of more than once
  23 if(typeof window.pz2 == "undefined") {
  24 window.undefined = window.undefined;
  25
  26 var pz2 = function ( paramArray )
  27 {
  28
  29     // at least one callback required
  30     if ( !paramArray )
  31         throw new Error("Pz2.js: Array with parameters has to be suplied.");
  32
  33     //supported pazpar2's protocol version
  34     this.suppProtoVer = '1';
  35     if (typeof paramArray.pazpar2path != "undefined")
  36         this.pz2String = paramArray.pazpar2path;
  37     else
  38         this.pz2String = "/pazpar2/search.pz2";
  39     this.useSessions = true;
  40
  41     this.stylesheet = paramArray.detailstylesheet || null;
  42     //load stylesheet if required in async mode
  43     if( this.stylesheet ) {
  44         var context = this;
  45         var request = new pzHttpRequest( this.stylesheet );
  46         request.get( {}, function ( doc ) { context.xslDoc = doc; } );
  47     }
  48
  49     this.errorHandler = paramArray.errorhandler || null;
  50
  51     // function callbacks
  52     this.initCallback = paramArray.oninit || null;
  53     this.statCallback = paramArray.onstat || null;
  54     this.showCallback = paramArray.onshow || null;
  55     this.termlistCallback = paramArray.onterm || null;
  56     this.recordCallback = paramArray.onrecord || null;
  57     this.bytargetCallback = paramArray.onbytarget || null;
  58     this.resetCallback = paramArray.onreset || null;
  59
  60     // termlist keys
  61     this.termKeys = paramArray.termlist || "subject";
  62
  63     // some configurational stuff
  64     this.keepAlive = 50000;
  65
  66     if ( paramArray.keepAlive < this.keepAlive )
  67         this.keepAlive = paramArray.keepAlive;
  68
  69     this.sessionID = null;
  70     this.initStatusOK = false;
  71     this.pingStatusOK = false;
  72     this.searchStatusOK = false;
  73
  74     // for sorting
  75     this.currentSort = "relevance";
  76
  77     // where are we?
  78     this.currentStart = 0;
  79     this.currentNum = 20;
  80
  81     // last full record retrieved
  82     this.currRecID = null;
  83
  84     // current query
  85     this.currQuery = null;
  86
  87     //current raw record offset
  88     this.currRecOffset = null;
  89
  90     //timers
  91     this.statTime = paramArray.stattime || 1000;
  92     this.statTimer = null;
  93     this.termTime = paramArray.termtime || 1000;
  94     this.termTimer = null;
  95     this.showTime = paramArray.showtime || 1000;
  96     this.showTimer = null;
  97     this.showFastCount = 4;
  98     this.bytargetTime = paramArray.bytargettime || 1000;
  99     this.bytargetTimer = null;
 100     this.recordTime = paramArray.recordtime || 500;
 101     this.recordTimer = null;
 102
 103     // counters for each command and applied delay
 104     this.dumpFactor = 500;
 105     this.showCounter = 0;
 106     this.termCounter = 0;
 107     this.statCounter = 0;
 108     this.bytargetCounter = 0;
 109     this.recordCounter = 0;
 110
 111     // active clients, updated by stat and show
 112     // might be an issue since bytarget will poll accordingly
 113     this.activeClients = 1;
 114
 115     // if in proxy mode no need to init
 116     if (paramArray.usesessions != undefined) {
 117          this.useSessions = paramArray.usesessions;
 118         this.initStatusOK = true;
 119     }
 120     // else, auto init session or wait for a user init?
 121     if (this.useSessions && paramArray.autoInit !== false) {
 122         this.init();
 123     }
 124 };
 125
 126 pz2.prototype =
 127 {
 128     //error handler for async error throws
 129    throwError: function (errMsg, errCode)
 130    {
 131         var err = new Error(errMsg);
 132         if (errCode) err.code = errCode;
 133
 134         if (this.errorHandler) {
 135             this.errorHandler(err);
 136         }
 137         else {
 138             throw err;
 139         }
 140    },
 141
 142     // stop activity by clearing tiemouts
 143    stop: function ()
 144    {
 145        clearTimeout(this.statTimer);
 146        clearTimeout(this.showTimer);
 147        clearTimeout(this.termTimer);
 148        clearTimeout(this.bytargetTimer);
 149     },
 150
 151     // reset status variables
 152     reset: function ()
 153     {
 154         if ( this.useSessions ) {
 155             this.sessionID = null;
 156             this.initStatusOK = false;
 157             this.pingStatusOK = false;
 158         }
 159         this.searchStatusOK = false;
 160         this.stop();
 161
 162         if ( this.resetCallback )
 163                 this.resetCallback();
 164     },
 165
 166     init: function ( sessionId )
 167     {
 168         this.reset();
 169
 170         // session id as a param
 171         if ( sessionId != undefined && this.useSessions ) {
 172             this.initStatusOK = true;
 173             this.sessionID = sessionId;
 174             this.ping();
 175         // old school direct pazpar2 init
 176         } else if (this.useSessions) {
 177             var context = this;
 178             var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 179             request.safeGet(
 180                 { "command": "init" },
 181                 function(data) {
 182                     if ( data.getElementsByTagName("status")[0]
 183                             .childNodes[0].nodeValue == "OK" ) {
 184                         if ( data.getElementsByTagName("protocol")[0]
 185                                 .childNodes[0].nodeValue
 186                             != context.suppProtoVer )
 187                             throw new Error(
 188                                 "Server's protocol not supported by the client"
 189                             );
 190                         context.initStatusOK = true;
 191                         context.sessionID =
 192                             data.getElementsByTagName("session")[0]
 193                                 .childNodes[0].nodeValue;
 194                         setTimeout(
 195                             function () {
 196                                 context.ping();
 197                             },
 198                             context.keepAlive
 199                         );
 200                         if ( context.initCallback )
 201                             context.initCallback();
 202                     }
 203                     else
 204                         context.throwError('Init failed. Malformed WS resonse.',
 205                                             110);
 206                 }
 207             );
 208         // when through proxy no need to init
 209         } else {
 210             this.initStatusOK = true;
 211         }
 212     },
 213     // no need to ping explicitly
 214     ping: function ()
 215     {
 216         // pinging only makes sense when using pazpar2 directly
 217         if( !this.initStatusOK || !this.useSessions )
 218             throw new Error(
 219             'Pz2.js: Ping not allowed (proxy mode) or session not initialized.'
 220             );
 221         var context = this;
 222         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 223         request.safeGet(
 224             { "command": "ping", "session": this.sessionID },
 225             function(data) {
 226                 if ( data.getElementsByTagName("status")[0]
 227                         .childNodes[0].nodeValue == "OK" ) {
 228                     context.pingStatusOK = true;
 229                     setTimeout(
 230                         function () {
 231                             context.ping();
 232                         },
 233                         context.keepAlive
 234                     );
 235                 }
 236                 else
 237                     context.throwError('Ping failed. Malformed WS resonse.',
 238                                         111);
 239             }
 240         );
 241     },
 242     search: function (query, num, sort, filter, showfrom, addParamsArr)
 243     {
 244         clearTimeout(this.statTimer);
 245         clearTimeout(this.showTimer);
 246         clearTimeout(this.termTimer);
 247         clearTimeout(this.bytargetTimer);
 248
 249         this.showCounter = 0;
 250         this.termCounter = 0;
 251         this.bytargetCounter = 0;
 252         this.statCounter = 0;
 253
 254         // no proxy mode
 255         if( !this.initStatusOK )
 256             throw new Error('Pz2.js: session not initialized.');
 257
 258         if( query !== undefined )
 259             this.currQuery = query;
 260         else
 261             throw new Error("Pz2.js: no query supplied to the search command.");
 262
 263         if ( showfrom !== undefined )
 264             var start = showfrom;
 265         else
 266             var start = 0;
 267
 268         var searchParams = {
 269             "command": "search",
 270             "query": this.currQuery,
 271             "session": this.sessionID
 272         };
 273
 274         if (filter !== undefined)
 275             searchParams["filter"] = filter;
 276
 277         // copy additional parmeters, do not overwrite
 278         if (addParamsArr != undefined) {
 279             for (var prop in addParamsArr) {
 280                 if (!searchParams.hasOwnProperty(prop))
 281                     searchParams[prop] = addParamsArr[prop];
 282             }
 283         }
 284
 285         var context = this;
 286         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 287         request.safeGet(
 288             searchParams,
 289             function(data) {
 290                 if ( data.getElementsByTagName("status")[0]
 291                         .childNodes[0].nodeValue == "OK" ) {
 292                     context.searchStatusOK = true;
 293                     //piggyback search
 294                     context.show(start, num, sort);
 295                     if ( context.statCallback )
 296                         context.stat();
 297                     if ( context.termlistCallback )
 298                         context.termlist();
 299                     if ( context.bytargetCallback )
 300                         context.bytarget();
 301                 }
 302                 else
 303                     context.throwError('Search failed. Malformed WS resonse.',
 304                                         112);
 305             }
 306         );
 307     },
 308     stat: function()
 309     {
 310         if( !this.initStatusOK )
 311             throw new Error('Pz2.js: session not initialized.');
 312
 313         // if called explicitly takes precedence
 314         clearTimeout(this.statTimer);
 315
 316         var context = this;
 317         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 318         request.safeGet(
 319             { "command": "stat", "session": this.sessionID },
 320             function(data) {
 321                 if ( data.getElementsByTagName("stat") ) {
 322                     var activeClients =
 323                         Number( data.getElementsByTagName("activeclients")[0]
 324                                     .childNodes[0].nodeValue );
 325                     context.activeClients = activeClients;
 326
 327                     var stat = Element_parseChildNodes(data.documentElement);
 328
 329                     context.statCounter++;
 330                     var delay = context.statTime
 331                         + context.statCounter * context.dumpFactor;
 332
 333                     if ( activeClients > 0 )
 334                         context.statTimer =
 335                             setTimeout(
 336                                 function () {
 337                                     context.stat();
 338                                 },
 339                                 delay
 340                             );
 341                     context.statCallback(stat);
 342                 }
 343                 else
 344                     context.throwError('Stat failed. Malformed WS resonse.',
 345                                         113);
 346             }
 347         );
 348     },
 349     show: function(start, num, sort)
 350     {
 351         if( !this.searchStatusOK && this.useSessions )
 352             throw new Error(
 353                 'Pz2.js: show command has to be preceded with a search command.'
 354             );
 355
 356         // if called explicitly takes precedence
 357         clearTimeout(this.showTimer);
 358
 359         if( sort !== undefined )
 360             this.currentSort = sort;
 361         if( start !== undefined )
 362             this.currentStart = Number( start );
 363         if( num !== undefined )
 364             this.currentNum = Number( num );
 365
 366         var context = this;
 367         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 368         request.safeGet(
 369             {
 370                 "command": "show",
 371                 "session": this.sessionID,
 372                 "start": this.currentStart,
 373                 "num": this.currentNum,
 374                 "sort": this.currentSort,
 375                 "block": 1
 376             },
 377             function(data) {
 378                 if ( data.getElementsByTagName("status")[0]
 379                         .childNodes[0].nodeValue == "OK" ) {
 380                     // first parse the status data send along with records
 381                     // this is strictly bound to the format
 382                     var activeClients =
 383                         Number( data.getElementsByTagName("activeclients")[0]
 384                                     .childNodes[0].nodeValue );
 385                     context.activeClients = activeClients;
 386                     var show = {
 387                         "activeclients": activeClients,
 388                         "merged":
 389                             Number( data.getElementsByTagName("merged")[0]
 390                                         .childNodes[0].nodeValue ),
 391                         "total":
 392                             Number( data.getElementsByTagName("total")[0]
 393                                         .childNodes[0].nodeValue ),
 394                         "start":
 395                             Number( data.getElementsByTagName("start")[0]
 396                                         .childNodes[0].nodeValue ),
 397                         "num":
 398                             Number( data.getElementsByTagName("num")[0]
 399                                         .childNodes[0].nodeValue ),
 400                         "hits": []
 401                     };
 402                     // parse all the first-level nodes for all <hit> tags
 403                     var hits = data.getElementsByTagName("hit");
 404                     for (i = 0; i < hits.length; i++)
 405                         show.hits[i] = Element_parseChildNodes(hits[i]);
 406
 407                     context.showCounter++;
 408                     var delay = context.showTime;
 409                     if (context.showCounter > context.showFastCount)
 410                             delay += context.showCounter * context.dumpFactor;
 411                     if ( activeClients > 0 )
 412                         context.showTimer = setTimeout(
 413                             function () {
 414                                 context.show();
 415                             },
 416                             delay);
 417                     global_show = show;
 418                     context.showCallback(show);
 419                 }
 420                 else
 421                     context.throwError('Show failed. Malformed WS resonse.',
 422                                         114);
 423             }
 424         );
 425     },
 426     record: function(id, offset, syntax, handler)
 427     {
 428         // we may call record with no previous search if in proxy mode
 429         if(!this.searchStatusOK && this.useSessions)
 430            throw new Error(
 431             'Pz2.js: record command has to be preceded with a search command.'
 432             );
 433
 434         if( id !== undefined )
 435             this.currRecID = id;
 436
 437         var recordParams = {
 438             "command": "record",
 439             "session": this.sessionID,
 440             "id": this.currRecID
 441         };
 442
 443         this.currRecOffset = null;
 444         if (offset != undefined) {
 445             recordParams["offset"] = offset;
 446             this.currRecOffset = offset;
 447         }
 448
 449         if (syntax != undefined)
 450             recordParams['syntax'] = syntax;
 451
 452         //overwrite default callback id needed
 453         var callback = this.recordCallback;
 454         var args = undefined;
 455         if (handler != undefined) {
 456             callback = handler['callback'];
 457             args = handler['args'];
 458         }
 459
 460         var context = this;
 461         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 462
 463         request.safeGet(
 464             recordParams,
 465             function(data) {
 466                 var recordNode;
 467                 var record;
 468                 //raw record
 469                 if (context.currRecOffset !== null) {
 470                     record = new Array();
 471                     record['xmlDoc'] = data;
 472                     record['offset'] = context.currRecOffset;
 473                     callback(record, args);
 474                 //pz2 record
 475                 } else if ( recordNode =
 476                     data.getElementsByTagName("record")[0] ) {
 477                     // if stylesheet was fetched do not parse the response
 478                     if ( context.xslDoc ) {
 479                         record = new Array();
 480                         record['xmlDoc'] = data;
 481                         record['xslDoc'] = context.xslDoc;
 482                         record['recid'] =
 483                             recordNode.getElementsByTagName("recid")[0]
 484                                 .firstChild.nodeValue;
 485                     //parse record
 486                     } else {
 487                         record = Element_parseChildNodes(recordNode);
 488                     }
 489                     var activeClients =
 490                        Number( data.getElementsByTagName("activeclients")[0]
 491                                 .childNodes[0].nodeValue );
 492                     context.activeClients = activeClients;
 493                     context.recordCounter++;
 494                     var delay = context.recordTime + context.recordCounter * context.dumpFactor;
 495                     if ( activeClients > 0 )
 496                         context.recordTimer =
 497                            setTimeout (
 498                                function() {
 499                                   context.record(id, offset, syntax, handler);
 500                                   },
 501                                   delay
 502                                );
 503                     callback(record, args);
 504                 }
 505                 else
 506                     context.throwError('Record failed. Malformed WS resonse.',
 507                                         115);
 508             }
 509         );
 510     },
 511
 512     termlist: function()
 513     {
 514         if( !this.searchStatusOK && this.useSessions )
 515             throw new Error(
 516             'Pz2.js: termlist command has to be preceded with a search command.'
 517             );
 518
 519         // if called explicitly takes precedence
 520         clearTimeout(this.termTimer);
 521
 522         var context = this;
 523         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 524         request.safeGet(
 525             {
 526                 "command": "termlist",
 527                 "session": this.sessionID,
 528                 "name": this.termKeys
 529             },
 530             function(data) {
 531                 if ( data.getElementsByTagName("termlist") ) {
 532                     var activeClients =
 533                         Number( data.getElementsByTagName("activeclients")[0]
 534                                     .childNodes[0].nodeValue );
 535                     context.activeClients = activeClients;
 536                     var termList = { "activeclients":  activeClients };
 537                     var termLists = data.getElementsByTagName("list");
 538                     //for each termlist
 539                     for (i = 0; i < termLists.length; i++) {
 540                         var listName = termLists[i].getAttribute('name');
 541                         termList[listName] = new Array();
 542                         var terms = termLists[i].getElementsByTagName('term');
 543                         //for each term in the list
 544                         for (j = 0; j < terms.length; j++) {
 545                             var term = {
 546                                 "name":
 547                                     (terms[j].getElementsByTagName("name")[0]
 548                                         .childNodes.length
 549                                     ? terms[j].getElementsByTagName("name")[0]
 550                                         .childNodes[0].nodeValue
 551                                     : 'ERROR'),
 552                                 "freq":
 553                                     terms[j]
 554                                     .getElementsByTagName("frequency")[0]
 555                                     .childNodes[0].nodeValue || 'ERROR'
 556                             };
 557
 558                             var termIdNode =
 559                                 terms[j].getElementsByTagName("id");
 560                             if(terms[j].getElementsByTagName("id").length)
 561                                 term["id"] =
 562                                     termIdNode[0].childNodes[0].nodeValue;
 563                             termList[listName][j] = term;
 564                         }
 565                     }
 566
 567                     context.termCounter++;
 568                     var delay = context.termTime
 569                         + context.termCounter * context.dumpFactor;
 570                     if ( activeClients > 0 )
 571                         context.termTimer =
 572                             setTimeout(
 573                                 function () {
 574                                     context.termlist();
 575                                 },
 576                                 delay
 577                             );
 578
 579                    context.termlistCallback(termList);
 580                 }
 581                 else
 582                     context.throwError('Termlist failed. Malformed WS resonse.',
 583                                         116);
 584             }
 585         );
 586
 587     },
 588     bytarget: function()
 589     {
 590         if( !this.initStatusOK && this.useSessions )
 591             throw new Error(
 592             'Pz2.js: bytarget command has to be preceded with a search command.'
 593             );
 594
 595         // no need to continue
 596         if( !this.searchStatusOK )
 597             return;
 598
 599         // if called explicitly takes precedence
 600         clearTimeout(this.bytargetTimer);
 601
 602         var context = this;
 603         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 604         request.safeGet(
 605             { "command": "bytarget", "session": this.sessionID },
 606             function(data) {
 607                 if ( data.getElementsByTagName("status")[0]
 608                         .childNodes[0].nodeValue == "OK" ) {
 609                     var targetNodes = data.getElementsByTagName("target");
 610                     var bytarget = new Array();
 611                     for ( i = 0; i < targetNodes.length; i++) {
 612                         bytarget[i] = new Array();
 613                         for( j = 0; j < targetNodes[i].childNodes.length; j++ ) {
 614                             if ( targetNodes[i].childNodes[j].nodeType
 615                                 == Node.ELEMENT_NODE ) {
 616                                 var nodeName =
 617                                     targetNodes[i].childNodes[j].nodeName;
 618                                 var nodeText =
 619                                     targetNodes[i].childNodes[j]
 620                                         .firstChild.nodeValue;
 621                                 bytarget[i][nodeName] = nodeText;
 622                             }
 623                         }
 624                     }
 625
 626                     context.bytargetCounter++;
 627                     var delay = context.bytargetTime
 628                         + context.bytargetCounter * context.dumpFactor;
 629                     if ( context.activeClients > 0 )
 630                         context.bytargetTimer =
 631                             setTimeout(
 632                                 function () {
 633                                     context.bytarget();
 634                                 },
 635                                 delay
 636                             );
 637
 638                     context.bytargetCallback(bytarget);
 639                 }
 640                 else
 641                     context.throwError('Bytarget failed. Malformed WS resonse.',
 642                                         117);
 643             }
 644         );
 645     },
 646
 647     // just for testing, probably shouldn't be here
 648     showNext: function(page)
 649     {
 650         var step = page || 1;
 651         this.show( ( step * this.currentNum ) + this.currentStart );
 652     },
 653
 654     showPrev: function(page)
 655     {
 656         if (this.currentStart == 0 )
 657             return false;
 658         var step = page || 1;
 659         var newStart = this.currentStart - (step * this.currentNum );
 660         this.show( newStart > 0 ? newStart : 0 );
 661     },
 662
 663     showPage: function(pageNum)
 664     {
 665         //var page = pageNum || 1;
 666         this.show(pageNum * this.currentNum);
 667     }
 668 };
 669
 670 /*
 671 ********************************************************************************
 672 ** AJAX HELPER CLASS ***********************************************************
 673 ********************************************************************************
 674 */
 675 var pzHttpRequest = function ( url, errorHandler ) {
 676         this.maxUrlLength = 2048;
 677         this.request = null;
 678         this.url = url;
 679         this.errorHandler = errorHandler || null;
 680         this.async = true;
 681         this.requestHeaders = {};
 682
 683         if ( window.XMLHttpRequest ) {
 684             this.request = new XMLHttpRequest();
 685         } else if ( window.ActiveXObject ) {
 686             try {
 687                 this.request = new ActiveXObject( 'Msxml2.XMLHTTP' );
 688             } catch (err) {
 689                 this.request = new ActiveXObject( 'Microsoft.XMLHTTP' );
 690             }
 691         }
 692 };
 693
 694 pzHttpRequest.prototype =
 695 {
 696     safeGet: function ( params, callback )
 697     {
 698         var encodedParams =  this.encodeParams(params);
 699         var url = this._urlAppendParams(encodedParams);
 700         if (url.length >= this.maxUrlLength) {
 701             this.requestHeaders["Content-Type"]
 702                 = "application/x-www-form-urlencoded";
 703             this._send( 'POST', this.url, encodedParams, callback );
 704         } else {
 705             this._send( 'GET', url, '', callback );
 706         }
 707     },
 708
 709     get: function ( params, callback )
 710     {
 711         this._send( 'GET', this._urlAppendParams(this.encodeParams(params)),
 712             '', callback );
 713     },
 714
 715     post: function ( params, data, callback )
 716     {
 717         this._send( 'POST', this._urlAppendParams(this.encodeParams(params)),
 718             data, callback );
 719     },
 720
 721     load: function ()
 722     {
 723         this.async = false;
 724         this.request.open( 'GET', this.url, this.async );
 725         this.request.send('');
 726         if ( this.request.status == 200 )
 727             return this.request.responseXML;
 728     },
 729
 730     encodeParams: function (params)
 731     {
 732         var sep = "";
 733         var encoded = "";
 734         for (var key in params) {
 735             if (params[key] != null) {
 736                 encoded += sep + key + '=' + encodeURIComponent(params[key]);
 737                 sep = '&';
 738             }
 739         }
 740         return encoded;
 741     },
 742
 743     _send: function ( type, url, data, callback)
 744     {
 745         var context = this;
 746         this.callback = callback;
 747         this.async = true;
 748         this.request.open( type, url, this.async );
 749         for (var key in this.requestHeaders)
 750             this.request.setRequestHeader(key, this.requestHeaders[key]);
 751         this.request.onreadystatechange = function () {
 752             context._handleResponse(url); /// url used ONLY for error reporting
 753         }
 754         this.request.send(data);
 755     },
 756
 757     _urlAppendParams: function (encodedParams)
 758     {
 759         if (encodedParams)
 760             return this.url + "?" + encodedParams;
 761         else
 762             return this.url;
 763     },
 764
 765     _handleResponse: function (savedUrlForErrorReporting)
 766     {
 767         if ( this.request.readyState == 4 ) {
 768             // pick up appplication errors first
 769             var errNode = null;
 770             if (this.request.responseXML &&
 771                 (errNode = this.request.responseXML.documentElement)
 772                 && errNode.nodeName == 'error') {
 773                 var errMsg = errNode.getAttribute("msg");
 774                 var errCode = errNode.getAttribute("code");
 775                 var errAddInfo = '';
 776                 if (errNode.childNodes.length)
 777                     errAddInfo = ': ' + errNode.childNodes[0].nodeValue;
 778
 779                 var err = new Error(errMsg + errAddInfo);
 780                 err.code = errCode;
 781
 782                 if (this.errorHandler) {
 783                     this.errorHandler(err);
 784                 }
 785                 else {
 786                     throw err;
 787                 }
 788             } else if (this.request.status == 200 &&
 789                        this.request.responseXML == null) {
 790                 var err = new Error("XML response is empty but no error " +
 791                                     "for " + savedUrlForErrorReporting);
 792                 err.code = -1;
 793                 if (this.errorHandler) {
 794                     this.errorHandler(err);
 795                 } else {
 796                     throw err;
 797                 }
 798             } else if (this.request.status == 200) {
 799                 this.callback(this.request.responseXML);
 800             } else {
 801                 var err = new Error("HTTP response not OK: "
 802                             + this.request.status + " - "
 803                             + this.request.statusText );
 804                 err.code = '00' + this.request.status;
 805
 806                 if (this.errorHandler) {
 807                     this.errorHandler(err);
 808                 }
 809                 else {
 810                     throw err;
 811                 }
 812             }
 813         }
 814     }
 815 };
 816
 817 /*
 818 ********************************************************************************
 819 ** XML HELPER FUNCTIONS ********************************************************
 820 ********************************************************************************
 821 */
 822
 823 // DOMDocument
 824
 825 if ( window.ActiveXObject) {
 826     var DOMDoc = document;
 827 } else {
 828     var DOMDoc = Document.prototype;
 829 }
 830
 831 DOMDoc.newXmlDoc = function ( root )
 832 {
 833     var doc;
 834
 835     if (document.implementation && document.implementation.createDocument) {
 836         doc = document.implementation.createDocument('', root, null);
 837     } else if ( window.ActiveXObject ) {
 838         doc = new ActiveXObject("MSXML2.DOMDocument");
 839         doc.loadXML('<' + root + '/>');
 840     } else {
 841         throw new Error ('No XML support in this browser');
 842     }
 843
 844     return doc;
 845 }
 846
 847
 848 DOMDoc.parseXmlFromString = function ( xmlString )
 849 {
 850     var doc;
 851
 852     if ( window.DOMParser ) {
 853         var parser = new DOMParser();
 854         doc = parser.parseFromString( xmlString, "text/xml");
 855     } else if ( window.ActiveXObject ) {
 856         doc = new ActiveXObject("MSXML2.DOMDocument");
 857         doc.loadXML( xmlString );
 858     } else {
 859         throw new Error ("No XML parsing support in this browser.");
 860     }
 861
 862     return doc;
 863 }
 864
 865 DOMDoc.transformToDoc = function (xmlDoc, xslDoc)
 866 {
 867     if ( window.XSLTProcessor ) {
 868         var proc = new XSLTProcessor();
 869         proc.importStylesheet( xslDoc );
 870         return proc.transformToDocument(xmlDoc);
 871     } else if ( window.ActiveXObject ) {
 872         return document.parseXmlFromString(xmlDoc.transformNode(xslDoc));
 873     } else {
 874         alert( 'Unable to perform XSLT transformation in this browser' );
 875     }
 876 }
 877
 878 // DOMElement
 879
 880 Element_removeFromDoc = function (DOM_Element)
 881 {
 882     DOM_Element.parentNode.removeChild(DOM_Element);
 883 }
 884
 885 Element_emptyChildren = function (DOM_Element)
 886 {
 887     while( DOM_Element.firstChild ) {
 888         DOM_Element.removeChild( DOM_Element.firstChild )
 889     }
 890 }
 891
 892 Element_appendTransformResult = function ( DOM_Element, xmlDoc, xslDoc )
 893 {
 894     if ( window.XSLTProcessor ) {
 895         var proc = new XSLTProcessor();
 896         proc.importStylesheet( xslDoc );
 897         var docFrag = false;
 898         docFrag = proc.transformToFragment( xmlDoc, DOM_Element.ownerDocument );
 899         DOM_Element.appendChild(docFrag);
 900     } else if ( window.ActiveXObject ) {
 901         DOM_Element.innerHTML = xmlDoc.transformNode( xslDoc );
 902     } else {
 903         alert( 'Unable to perform XSLT transformation in this browser' );
 904     }
 905 }
 906
 907 Element_appendTextNode = function (DOM_Element, tagName, textContent )
 908 {
 909     var node = DOM_Element.ownerDocument.createElement(tagName);
 910     var text = DOM_Element.ownerDocument.createTextNode(textContent);
 911
 912     DOM_Element.appendChild(node);
 913     node.appendChild(text);
 914
 915     return node;
 916 }
 917
 918 Element_setTextContent = function ( DOM_Element, textContent )
 919 {
 920     if (typeof DOM_Element.textContent !== "undefined") {
 921         DOM_Element.textContent = textContent;
 922     } else if (typeof DOM_Element.innerText !== "undefined" ) {
 923         DOM_Element.innerText = textContent;
 924     } else {
 925         throw new Error("Cannot set text content of the node, no such method.");
 926     }
 927 }
 928
 929 Element_getTextContent = function (DOM_Element)
 930 {
 931     if ( typeof DOM_Element.textContent != 'undefined' ) {
 932         return DOM_Element.textContent;
 933     } else if (typeof DOM_Element.text != 'undefined') {
 934         return DOM_Element.text;
 935     } else {
 936         throw new Error("Cannot get text content of the node, no such method.");
 937     }
 938 }
 939
 940 Element_parseChildNodes = function (node)
 941 {
 942     var parsed = {};
 943     var hasChildElems = false;
 944
 945     if (node.hasChildNodes()) {
 946         var children = node.childNodes;
 947         for (var i = 0; i < children.length; i++) {
 948             var child = children[i];
 949             if (child.nodeType == Node.ELEMENT_NODE) {
 950                 hasChildElems = true;
 951                 var nodeName = child.nodeName;
 952                 if (!(nodeName in parsed))
 953                     parsed[nodeName] = [];
 954                 parsed[nodeName].push(Element_parseChildNodes(child));
 955             }
 956         }
 957     }
 958
 959     var attrs = node.attributes;
 960     for (var i = 0; i < attrs.length; i++) {
 961         var attrName = '@' + attrs[i].nodeName;
 962         var attrValue = attrs[i].nodeValue;
 963         parsed[attrName] = attrValue;
 964     }
 965
 966     // if no nested elements, get text content
 967     if (node.hasChildNodes() && !hasChildElems) {
 968         if (node.attributes.length)
 969             parsed['textContent'] = node.firstChild.nodeValue;
 970         else
 971             parsed = node.firstChild.nodeValue;
 972     }
 973
 974     return parsed;
 975 }
 976
 977 /* do not remove trailing bracket */
 978 }