js/pz2.js

   1 /*
   2  * Mine
   3 ** pz2.js - pazpar2's javascript client library.
   4 */
   5
   6 //since explorer is flawed
   7 if (!window['Node']) {
   8     window.Node = new Object();
   9     Node.ELEMENT_NODE = 1;
  10     Node.ATTRIBUTE_NODE = 2;
  11     Node.TEXT_NODE = 3;
  12     Node.CDATA_SECTION_NODE = 4;
  13     Node.ENTITY_REFERENCE_NODE = 5;
  14     Node.ENTITY_NODE = 6;
  15     Node.PROCESSING_INSTRUCTION_NODE = 7;
  16     Node.COMMENT_NODE = 8;
  17     Node.DOCUMENT_NODE = 9;
  18     Node.DOCUMENT_TYPE_NODE = 10;
  19     Node.DOCUMENT_FRAGMENT_NODE = 11;
  20     Node.NOTATION_NODE = 12;
  21 }
  22
  23 // prevent execution of more than once
  24 if(typeof window.pz2 == "undefined") {
  25 window.undefined = window.undefined;
  26
  27 var pz2 = function ( paramArray )
  28 {
  29
  30     // at least one callback required
  31     if ( !paramArray )
  32         throw new Error("Pz2.js: Array with parameters has to be suplied.");
  33
  34     //supported pazpar2's protocol version
  35     this.suppProtoVer = '1';
  36     if (typeof paramArray.pazpar2path != "undefined")
  37         this.pz2String = paramArray.pazpar2path;
  38     else
  39         this.pz2String = "/pazpar2/search.pz2";
  40     this.useSessions = true;
  41
  42     this.stylesheet = paramArray.detailstylesheet || null;
  43     //load stylesheet if required in async mode
  44     if( this.stylesheet ) {
  45         var context = this;
  46         var request = new pzHttpRequest( this.stylesheet );
  47         request.get( {}, function ( doc ) { context.xslDoc = doc; } );
  48     }
  49
  50     this.errorHandler = paramArray.errorhandler || null;
  51     this.showResponseType = paramArray.showResponseType || "xml";
  52
  53     // function callbacks
  54     this.initCallback = paramArray.oninit || null;
  55     this.statCallback = paramArray.onstat || null;
  56     this.showCallback = paramArray.onshow || null;
  57     this.termlistCallback = paramArray.onterm || null;
  58     this.recordCallback = paramArray.onrecord || null;
  59     this.bytargetCallback = paramArray.onbytarget || null;
  60     this.resetCallback = paramArray.onreset || null;
  61
  62     // termlist keys
  63     this.termKeys = paramArray.termlist || "subject";
  64
  65     // some configurational stuff
  66     this.keepAlive = 50000;
  67
  68     if ( paramArray.keepAlive < this.keepAlive )
  69         this.keepAlive = paramArray.keepAlive;
  70
  71     this.sessionID = null;
  72     this.serviceId = paramArray.serviceId || null;
  73     this.initStatusOK = false;
  74     this.pingStatusOK = false;
  75     this.searchStatusOK = false;
  76
  77     // for sorting
  78     this.currentSort = "relevance";
  79
  80     // where are we?
  81     this.currentStart = 0;
  82     // currentNum can be overwritten in show
  83     this.currentNum = 20;
  84
  85     // last full record retrieved
  86     this.currRecID = null;
  87
  88     // current query
  89     this.currQuery = null;
  90
  91     //current raw record offset
  92     this.currRecOffset = null;
  93
  94     //timers
  95     this.pingTimer = null;
  96     this.statTime = paramArray.stattime || 1000;
  97     this.statTimer = null;
  98     this.termTime = paramArray.termtime || 1000;
  99     this.termTimer = null;
 100     this.showTime = paramArray.showtime || 1000;
 101     this.showTimer = null;
 102     this.showFastCount = 4;
 103     this.bytargetTime = paramArray.bytargettime || 1000;
 104     this.bytargetTimer = null;
 105     this.recordTime = paramArray.recordtime || 500;
 106     this.recordTimer = null;
 107
 108     // counters for each command and applied delay
 109     this.dumpFactor = 500;
 110     this.showCounter = 0;
 111     this.termCounter = 0;
 112     this.statCounter = 0;
 113     this.bytargetCounter = 0;
 114     this.recordCounter = 0;
 115
 116     // active clients, updated by stat and show
 117     // might be an issue since bytarget will poll accordingly
 118     this.activeClients = 1;
 119
 120     // if in proxy mode no need to init
 121     if (paramArray.usesessions != undefined) {
 122          this.useSessions = paramArray.usesessions;
 123         this.initStatusOK = true;
 124     }
 125     // else, auto init session or wait for a user init?
 126     if (this.useSessions && paramArray.autoInit !== false) {
 127         this.init(this.sessionId, this.serviceId);
 128     }
 129 };
 130
 131 pz2.prototype =
 132 {
 133     //error handler for async error throws
 134    throwError: function (errMsg, errCode)
 135    {
 136         var err = new Error(errMsg);
 137         if (errCode) err.code = errCode;
 138
 139         if (this.errorHandler) {
 140             this.errorHandler(err);
 141         }
 142         else {
 143             throw err;
 144         }
 145    },
 146
 147     // stop activity by clearing tiemouts
 148    stop: function ()
 149    {
 150        clearTimeout(this.statTimer);
 151        clearTimeout(this.showTimer);
 152        clearTimeout(this.termTimer);
 153        clearTimeout(this.bytargetTimer);
 154     },
 155
 156     // reset status variables
 157     reset: function ()
 158     {
 159         if ( this.useSessions ) {
 160             this.sessionID = null;
 161             this.initStatusOK = false;
 162             this.pingStatusOK = false;
 163             clearTimeout(this.pingTimer);
 164         }
 165         this.searchStatusOK = false;
 166         this.stop();
 167
 168         if ( this.resetCallback )
 169                 this.resetCallback();
 170     },
 171
 172     init: function (sessionId, serviceId)
 173     {
 174         this.reset();
 175
 176         // session id as a param
 177         if (sessionId && this.useSessions ) {
 178             this.initStatusOK = true;
 179             this.sessionID = sessionId;
 180             this.ping();
 181         // old school direct pazpar2 init
 182         } else if (this.useSessions) {
 183             var context = this;
 184             var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 185             var opts = {'command' : 'init'};
 186             if (serviceId) opts.service = serviceId;
 187             request.safeGet(
 188                 opts,
 189                 function(data) {
 190                     if ( data.getElementsByTagName("status")[0]
 191                             .childNodes[0].nodeValue == "OK" ) {
 192                         if ( data.getElementsByTagName("protocol")[0]
 193                                 .childNodes[0].nodeValue
 194                             != context.suppProtoVer )
 195                             throw new Error(
 196                                 "Server's protocol not supported by the client"
 197                             );
 198                         context.initStatusOK = true;
 199                         context.sessionID =
 200                             data.getElementsByTagName("session")[0]
 201                                 .childNodes[0].nodeValue;
 202                         context.pingTimer =
 203                             setTimeout(
 204                                 function () {
 205                                     context.ping();
 206                                 },
 207                                 context.keepAlive
 208                             );
 209                         if ( context.initCallback )
 210                             context.initCallback();
 211                     }
 212                     else
 213                         context.throwError('Init failed. Malformed WS resonse.',
 214                                             110);
 215                 }
 216             );
 217         // when through proxy no need to init
 218         } else {
 219             this.initStatusOK = true;
 220         }
 221     },
 222     // no need to ping explicitly
 223     ping: function ()
 224     {
 225         // pinging only makes sense when using pazpar2 directly
 226         if( !this.initStatusOK || !this.useSessions )
 227             throw new Error(
 228             'Pz2.js: Ping not allowed (proxy mode) or session not initialized.'
 229             );
 230         var context = this;
 231
 232         clearTimeout(context.pingTimer);
 233
 234         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 235         request.safeGet(
 236             { "command": "ping", "session": this.sessionID, "windowid" : window.name },
 237             function(data) {
 238                 if ( data.getElementsByTagName("status")[0]
 239                         .childNodes[0].nodeValue == "OK" ) {
 240                     context.pingStatusOK = true;
 241                     context.pingTimer =
 242                         setTimeout(
 243                             function () {
 244                                 context.ping();
 245                             },
 246                             context.keepAlive
 247                         );
 248                 }
 249                 else
 250                     context.throwError('Ping failed. Malformed WS resonse.',
 251                                         111);
 252             }
 253         );
 254     },
 255     search: function (query, num, sort, filter, showfrom, addParamsArr)
 256     {
 257         clearTimeout(this.statTimer);
 258         clearTimeout(this.showTimer);
 259         clearTimeout(this.termTimer);
 260         clearTimeout(this.bytargetTimer);
 261
 262         this.showCounter = 0;
 263         this.termCounter = 0;
 264         this.bytargetCounter = 0;
 265         this.statCounter = 0;
 266         this.activeClients = 1;
 267
 268         // no proxy mode
 269         if( !this.initStatusOK )
 270             throw new Error('Pz2.js: session not initialized.');
 271
 272         if( query !== undefined )
 273             this.currQuery = query;
 274         else
 275             throw new Error("Pz2.js: no query supplied to the search command.");
 276
 277         if ( showfrom !== undefined )
 278             var start = showfrom;
 279         else
 280             var start = 0;
 281
 282               var searchParams = {
 283           "command": "search",
 284           "query": this.currQuery,
 285           "session": this.sessionID,
 286           "windowid" : window.name
 287         };
 288
 289         if (filter !== undefined)
 290                 searchParams["filter"] = filter;
 291
 292         // copy additional parmeters, do not overwrite
 293         if (addParamsArr != undefined) {
 294             for (var prop in addParamsArr) {
 295                 if (!searchParams.hasOwnProperty(prop))
 296                     searchParams[prop] = addParamsArr[prop];
 297             }
 298         }
 299
 300         var context = this;
 301         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 302         request.safeGet(
 303             searchParams,
 304             function(data) {
 305                 if ( data.getElementsByTagName("status")[0]
 306                         .childNodes[0].nodeValue == "OK" ) {
 307                     context.searchStatusOK = true;
 308                     //piggyback search
 309                     context.show(start, num, sort);
 310                     if (context.statCallback)
 311                         context.stat();
 312                     if (context.termlistCallback)
 313                         context.termlist();
 314                     if (context.bytargetCallback)
 315                         context.bytarget();
 316                 }
 317                 else
 318                     context.throwError('Search failed. Malformed WS resonse.',
 319                                         112);
 320             }
 321         );
 322     },
 323     stat: function()
 324     {
 325         if( !this.initStatusOK )
 326             throw new Error('Pz2.js: session not initialized.');
 327
 328         // if called explicitly takes precedence
 329         clearTimeout(this.statTimer);
 330
 331         var context = this;
 332         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 333         request.safeGet(
 334             { "command": "stat", "session": this.sessionID, "windowid" : window.name },
 335             function(data) {
 336                 if ( data.getElementsByTagName("stat") ) {
 337                     var activeClients =
 338                         Number( data.getElementsByTagName("activeclients")[0]
 339                                     .childNodes[0].nodeValue );
 340                     context.activeClients = activeClients;
 341
 342                     var stat = Element_parseChildNodes(data.documentElement);
 343
 344                     context.statCounter++;
 345                     var delay = context.statTime
 346                         + context.statCounter * context.dumpFactor;
 347
 348                     if ( activeClients > 0 )
 349                         context.statTimer =
 350                             setTimeout(
 351                                 function () {
 352                                     context.stat();
 353                                 },
 354                                 delay
 355                             );
 356                     context.statCallback(stat);
 357                 }
 358                 else
 359                     context.throwError('Stat failed. Malformed WS resonse.',
 360                                         113);
 361             }
 362         );
 363     },
 364     show: function(start, num, sort, query_state)
 365     {
 366         if( !this.searchStatusOK && this.useSessions )
 367             throw new Error(
 368                 'Pz2.js: show command has to be preceded with a search command.'
 369             );
 370
 371         // if called explicitly takes precedence
 372         clearTimeout(this.showTimer);
 373
 374         if( sort !== undefined )
 375             this.currentSort = sort;
 376         if( start !== undefined )
 377             this.currentStart = Number( start );
 378         if( num !== undefined )
 379             this.currentNum = Number( num );
 380
 381         var context = this;
 382         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 383         var requestParameters =
 384           {
 385             "command": "show",
 386             "session": this.sessionID,
 387             "start": this.currentStart,
 388             "num": this.currentNum,
 389             "sort": this.currentSort,
 390             "block": 1,
 391             "type": this.showResponseType,
 392             "windowid" : window.name
 393           };
 394         if (query_state)
 395           requestParameters["query-state"] = query_state;
 396         request.safeGet(
 397           requestParameters,
 398           function(data, type) {
 399             var show = null;
 400             var activeClients = 0;
 401             if (type === "json") {
 402               show = {};
 403               activeClients = Number(data.activeclients[0]);
 404               show.activeclients = activeClients;
 405               show.merged = Number(data.merged[0]);
 406               show.total = Number(data.total[0]);
 407               show.start = Number(data.start[0]);
 408               show.num = Number(data.num[0]);
 409               show.hits = data.hit;
 410             } else if (data.getElementsByTagName("status")[0]
 411                   .childNodes[0].nodeValue == "OK") {
 412                 // first parse the status data send along with records
 413                 // this is strictly bound to the format
 414                 activeClients =
 415                   Number(data.getElementsByTagName("activeclients")[0]
 416                       .childNodes[0].nodeValue);
 417                 show = {
 418                   "activeclients": activeClients,
 419                   "merged":
 420                     Number( data.getElementsByTagName("merged")[0]
 421                         .childNodes[0].nodeValue ),
 422                   "total":
 423                     Number( data.getElementsByTagName("total")[0]
 424                         .childNodes[0].nodeValue ),
 425                   "start":
 426                     Number( data.getElementsByTagName("start")[0]
 427                         .childNodes[0].nodeValue ),
 428                   "num":
 429                     Number( data.getElementsByTagName("num")[0]
 430                         .childNodes[0].nodeValue ),
 431                   "hits": []
 432                 };
 433                 // parse all the first-level nodes for all <hit> tags
 434                 var hits = data.getElementsByTagName("hit");
 435                 for (i = 0; i < hits.length; i++)
 436                   show.hits[i] = Element_parseChildNodes(hits[i]);
 437             } else {
 438               context.throwError('Show failed. Malformed WS resonse.',
 439                   114);
 440             }
 441             context.activeClients = activeClients;
 442             context.showCounter++;
 443             var delay = context.showTime;
 444             if (context.showCounter > context.showFastCount)
 445               delay += context.showCounter * context.dumpFactor;
 446             if ( activeClients > 0 )
 447               context.showTimer = setTimeout(
 448                 function () {
 449                   context.show();
 450                 },
 451                 delay);
 452             context.showCallback(show);
 453           }
 454         );
 455     },
 456     record: function(id, offset, syntax, handler)
 457     {
 458         // we may call record with no previous search if in proxy mode
 459         if(!this.searchStatusOK && this.useSessions)
 460            throw new Error(
 461             'Pz2.js: record command has to be preceded with a search command.'
 462             );
 463
 464         if( id !== undefined )
 465             this.currRecID = id;
 466
 467         var recordParams = {
 468             "command": "record",
 469             "session": this.sessionID,
 470             "id": this.currRecID,
 471             "windowid" : window.name
 472         };
 473
 474         this.currRecOffset = null;
 475         if (offset != undefined) {
 476             recordParams["offset"] = offset;
 477             this.currRecOffset = offset;
 478         }
 479
 480         if (syntax != undefined)
 481             recordParams['syntax'] = syntax;
 482
 483         //overwrite default callback id needed
 484         var callback = this.recordCallback;
 485         var args = undefined;
 486         if (handler != undefined) {
 487             callback = handler['callback'];
 488             args = handler['args'];
 489         }
 490
 491         var context = this;
 492         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 493
 494         request.safeGet(
 495             recordParams,
 496             function(data) {
 497                 var recordNode;
 498                 var record;
 499                 //raw record
 500                 if (context.currRecOffset !== null) {
 501                     record = new Array();
 502                     record['xmlDoc'] = data;
 503                     record['offset'] = context.currRecOffset;
 504                     callback(record, args);
 505                 //pz2 record
 506                 } else if ( recordNode =
 507                     data.getElementsByTagName("record")[0] ) {
 508                     // if stylesheet was fetched do not parse the response
 509                     if ( context.xslDoc ) {
 510                         record = new Array();
 511                         record['xmlDoc'] = data;
 512                         record['xslDoc'] = context.xslDoc;
 513                         record['recid'] =
 514                             recordNode.getElementsByTagName("recid")[0]
 515                                 .firstChild.nodeValue;
 516                     //parse record
 517                     } else {
 518                         record = Element_parseChildNodes(recordNode);
 519                     }
 520                     var activeClients =
 521                        Number( data.getElementsByTagName("activeclients")[0]
 522                                 .childNodes[0].nodeValue );
 523                     context.activeClients = activeClients;
 524                     context.recordCounter++;
 525                     var delay = context.recordTime + context.recordCounter * context.dumpFactor;
 526                     if ( activeClients > 0 )
 527                         context.recordTimer =
 528                            setTimeout (
 529                                function() {
 530                                   context.record(id, offset, syntax, handler);
 531                                   },
 532                                   delay
 533                                );
 534                     callback(record, args);
 535                 }
 536                 else
 537                     context.throwError('Record failed. Malformed WS resonse.',
 538                                         115);
 539             }
 540         );
 541     },
 542
 543     termlist: function()
 544     {
 545         if( !this.searchStatusOK && this.useSessions )
 546             throw new Error(
 547             'Pz2.js: termlist command has to be preceded with a search command.'
 548             );
 549
 550         // if called explicitly takes precedence
 551         clearTimeout(this.termTimer);
 552
 553         var context = this;
 554         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 555         request.safeGet(
 556             {
 557                 "command": "termlist",
 558                 "session": this.sessionID,
 559                 "name": this.termKeys,
 560                 "windowid" : window.name
 561             },
 562             function(data) {
 563                 if ( data.getElementsByTagName("termlist") ) {
 564                     var activeClients =
 565                         Number( data.getElementsByTagName("activeclients")[0]
 566                                     .childNodes[0].nodeValue );
 567                     context.activeClients = activeClients;
 568                     var termList = { "activeclients":  activeClients };
 569                     var termLists = data.getElementsByTagName("list");
 570                     //for each termlist
 571                     for (i = 0; i < termLists.length; i++) {
 572                         var listName = termLists[i].getAttribute('name');
 573                         termList[listName] = new Array();
 574                         var terms = termLists[i].getElementsByTagName('term');
 575                         //for each term in the list
 576                         for (j = 0; j < terms.length; j++) {
 577                             var term = {
 578                                 "name":
 579                                     (terms[j].getElementsByTagName("name")[0]
 580                                         .childNodes.length
 581                                     ? terms[j].getElementsByTagName("name")[0]
 582                                         .childNodes[0].nodeValue
 583                                     : 'ERROR'),
 584                                 "freq":
 585                                     terms[j]
 586                                     .getElementsByTagName("frequency")[0]
 587                                     .childNodes[0].nodeValue || 'ERROR'
 588                             };
 589
 590                             var termIdNode =
 591                                 terms[j].getElementsByTagName("id");
 592                             if(terms[j].getElementsByTagName("id").length)
 593                                 term["id"] =
 594                                     termIdNode[0].childNodes[0].nodeValue;
 595                             termList[listName][j] = term;
 596                         }
 597                     }
 598
 599                     context.termCounter++;
 600                     var delay = context.termTime
 601                         + context.termCounter * context.dumpFactor;
 602                     if ( activeClients > 0 )
 603                         context.termTimer =
 604                             setTimeout(
 605                                 function () {
 606                                     context.termlist();
 607                                 },
 608                                 delay
 609                             );
 610
 611                    context.termlistCallback(termList);
 612                 }
 613                 else
 614                     context.throwError('Termlist failed. Malformed WS resonse.',
 615                                         116);
 616             }
 617         );
 618
 619     },
 620     bytarget: function()
 621     {
 622         if( !this.initStatusOK && this.useSessions )
 623             throw new Error(
 624             'Pz2.js: bytarget command has to be preceded with a search command.'
 625             );
 626
 627         // no need to continue
 628         if( !this.searchStatusOK )
 629             return;
 630
 631         // if called explicitly takes precedence
 632         clearTimeout(this.bytargetTimer);
 633
 634         var context = this;
 635         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 636         request.safeGet(
 637             {
 638                 "command": "bytarget",
 639                 "session": this.sessionID,
 640                 "block": 1,
 641                 "windowid" : window.name
 642             },
 643             function(data) {
 644                 if ( data.getElementsByTagName("status")[0]
 645                         .childNodes[0].nodeValue == "OK" ) {
 646                     var targetNodes = data.getElementsByTagName("target");
 647                     var bytarget = new Array();
 648                     for ( i = 0; i < targetNodes.length; i++) {
 649                         bytarget[i] = new Array();
 650                         for( j = 0; j < targetNodes[i].childNodes.length; j++ ) {
 651                             if ( targetNodes[i].childNodes[j].nodeType
 652                                 == Node.ELEMENT_NODE ) {
 653                                 var nodeName =
 654                                     targetNodes[i].childNodes[j].nodeName;
 655                                 if (targetNodes[i].childNodes[j].firstChild != null)
 656                                 {
 657                                     var nodeText = targetNodes[i].childNodes[j]
 658                                         .firstChild.nodeValue;
 659                                     bytarget[i][nodeName] = nodeText;
 660                                 }
 661                                 else {
 662                                     bytarget[i][nodeName] = "";
 663                                 }
 664
 665
 666                             }
 667                         }
 668                         if (bytarget[i]["state"]=="Client_Disconnected") {
 669                           bytarget[i]["hits"] = "Error";
 670                         } else if (bytarget[i]["state"]=="Client_Error") {
 671                           bytarget[i]["hits"] = "Error";
 672                         } else if (bytarget[i]["state"]=="Client_Working") {
 673                           bytarget[i]["hits"] = "...";
 674                         }
 675                         if (bytarget[i].diagnostic == "1") {
 676                           bytarget[i].diagnostic = "Permanent system error";
 677                         } else if (bytarget[i].diagnostic == "2") {
 678                           bytarget[i].diagnostic = "Temporary system error";
 679                         }
 680                         var targetsSuggestions = targetNodes[i].getElementsByTagName("suggestions");
 681                         if (targetsSuggestions != undefined && targetsSuggestions.length>0) {
 682                           var suggestions = targetsSuggestions[0];
 683                           bytarget[i]["suggestions"] = Element_parseChildNodes(suggestions);
 684                         }
 685                     }
 686
 687                     context.bytargetCounter++;
 688                     var delay = context.bytargetTime
 689                         + context.bytargetCounter * context.dumpFactor;
 690                     if ( context.activeClients > 0 )
 691                         context.bytargetTimer =
 692                             setTimeout(
 693                                 function () {
 694                                     context.bytarget();
 695                                 },
 696                                 delay
 697                             );
 698
 699                     context.bytargetCallback(bytarget);
 700                 }
 701                 else
 702                     context.throwError('Bytarget failed. Malformed WS resonse.',
 703                                         117);
 704             }
 705         );
 706     },
 707
 708     // just for testing, probably shouldn't be here
 709     showNext: function(page)
 710     {
 711         var step = page || 1;
 712         this.show( ( step * this.currentNum ) + this.currentStart );
 713     },
 714
 715     showPrev: function(page)
 716     {
 717         if (this.currentStart == 0 )
 718             return false;
 719         var step = page || 1;
 720         var newStart = this.currentStart - (step * this.currentNum );
 721         this.show( newStart > 0 ? newStart : 0 );
 722     },
 723
 724     showPage: function(pageNum)
 725     {
 726         //var page = pageNum || 1;
 727         this.show(pageNum * this.currentNum);
 728     }
 729 };
 730
 731 /*
 732 ********************************************************************************
 733 ** AJAX HELPER CLASS ***********************************************************
 734 ********************************************************************************
 735 */
 736 var pzHttpRequest = function ( url, errorHandler ) {
 737         this.maxUrlLength = 2048;
 738         this.request = null;
 739         this.url = url;
 740         this.errorHandler = errorHandler || null;
 741         this.async = true;
 742         this.requestHeaders = {};
 743
 744         if ( window.XMLHttpRequest ) {
 745             this.request = new XMLHttpRequest();
 746         } else if ( window.ActiveXObject ) {
 747             try {
 748                 this.request = new ActiveXObject( 'Msxml2.XMLHTTP' );
 749             } catch (err) {
 750                 this.request = new ActiveXObject( 'Microsoft.XMLHTTP' );
 751             }
 752         }
 753 };
 754
 755
 756 pzHttpRequest.prototype =
 757 {
 758     safeGet: function ( params, callback )
 759     {
 760         var encodedParams =  this.encodeParams(params);
 761         var url = this._urlAppendParams(encodedParams);
 762         if (url.length >= this.maxUrlLength) {
 763             this.requestHeaders["Content-Type"]
 764                 = "application/x-www-form-urlencoded";
 765             this._send( 'POST', this.url, encodedParams, callback );
 766         } else {
 767             this._send( 'GET', url, '', callback );
 768         }
 769     },
 770
 771     get: function ( params, callback )
 772     {
 773         this._send( 'GET', this._urlAppendParams(this.encodeParams(params)),
 774             '', callback );
 775     },
 776
 777     post: function ( params, data, callback )
 778     {
 779         this._send( 'POST', this._urlAppendParams(this.encodeParams(params)),
 780             data, callback );
 781     },
 782
 783     load: function ()
 784     {
 785         this.async = false;
 786         this.request.open( 'GET', this.url, this.async );
 787         this.request.send('');
 788         if ( this.request.status == 200 )
 789             return this.request.responseXML;
 790     },
 791
 792     encodeParams: function (params)
 793     {
 794         var sep = "";
 795         var encoded = "";
 796         for (var key in params) {
 797             if (params[key] != null) {
 798                 encoded += sep + key + '=' + encodeURIComponent(params[key]);
 799                 sep = '&';
 800             }
 801         }
 802         return encoded;
 803     },
 804
 805     _send: function ( type, url, data, callback)
 806     {
 807         var context = this;
 808         this.callback = callback;
 809         this.async = true;
 810         this.request.open( type, url, this.async );
 811         for (var key in this.requestHeaders)
 812             this.request.setRequestHeader(key, this.requestHeaders[key]);
 813         this.request.onreadystatechange = function () {
 814             context._handleResponse(url); /// url used ONLY for error reporting
 815         }
 816         this.request.send(data);
 817     },
 818
 819     _urlAppendParams: function (encodedParams)
 820     {
 821         if (encodedParams)
 822             return this.url + "?" + encodedParams;
 823         else
 824             return this.url;
 825     },
 826
 827     _handleResponse: function (savedUrlForErrorReporting)
 828     {
 829         if ( this.request.readyState == 4 ) {
 830             // pick up appplication errors first
 831             var errNode = null;
 832             if (this.request.responseXML &&
 833                 (errNode = this.request.responseXML.documentElement)
 834                 && errNode.nodeName == 'error') {
 835                 var errMsg = errNode.getAttribute("msg");
 836                 var errCode = errNode.getAttribute("code");
 837                 var errAddInfo = '';
 838                 if (errNode.childNodes.length)
 839                     errAddInfo = ': ' + errNode.childNodes[0].nodeValue;
 840
 841                 var err = new Error(errMsg + errAddInfo);
 842                 err.code = errCode;
 843
 844                 if (this.errorHandler) {
 845                     this.errorHandler(err);
 846                 }
 847                 else {
 848                     throw err;
 849                 }
 850             } else if (this.request.status == 200 &&
 851                        this.request.responseXML == null) {
 852               if (this.request.responseText != null) {
 853                 //assume JSON
 854
 855                 var json = null;
 856                 var text = this.request.responseText;
 857                 if (typeof window.JSON == "undefined")
 858                     json = eval("(" + text + ")");
 859                 else {
 860                     try {
 861                         json = JSON.parse(text);
 862                     }
 863                     catch (e) {
 864                         // Safari: eval will fail as well. Considering trying JSON2 (non-native implementation) instead
 865                         /* DEBUG only works in mk2-mobile
 866                         if (document.getElementById("log"))
 867                             document.getElementById("log").innerHTML = "" + e + " " + length + ": " + text;
 868                         */
 869                         try {
 870                             json = eval("(" + text + ")");
 871                         }
 872                         catch (e) {
 873                             /* DEBUG only works in mk2-mobile
 874                             if (document.getElementById("log"))
 875                                 document.getElementById("log").innerHTML = "" + e + " " + length + ": " + text;
 876                             */
 877                         }
 878                     }
 879                 }
 880                 this.callback(json, "json");
 881               } else {
 882                 var err = new Error("XML response is empty but no error " +
 883                                     "for " + savedUrlForErrorReporting);
 884                 err.code = -1;
 885                 if (this.errorHandler) {
 886                     this.errorHandler(err);
 887                 } else {
 888                     throw err;
 889                 }
 890               }
 891             } else if (this.request.status == 200) {
 892                 this.callback(this.request.responseXML);
 893             } else {
 894                 var err = new Error("HTTP response not OK: "
 895                             + this.request.status + " - "
 896                             + this.request.statusText );
 897                 err.code = '00' + this.request.status;
 898                 if (this.errorHandler) {
 899                     this.errorHandler(err);
 900                 }
 901                 else {
 902                     throw err;
 903                 }
 904             }
 905         }
 906     }
 907 };
 908
 909 /*
 910 ********************************************************************************
 911 ** XML HELPER FUNCTIONS ********************************************************
 912 ********************************************************************************
 913 */
 914
 915 // DOMDocument
 916
 917 if ( window.ActiveXObject) {
 918     var DOMDoc = document;
 919 } else {
 920     var DOMDoc = Document.prototype;
 921 }
 922
 923 DOMDoc.newXmlDoc = function ( root )
 924 {
 925     var doc;
 926
 927     if (document.implementation && document.implementation.createDocument) {
 928         doc = document.implementation.createDocument('', root, null);
 929     } else if ( window.ActiveXObject ) {
 930         doc = new ActiveXObject("MSXML2.DOMDocument");
 931         doc.loadXML('<' + root + '/>');
 932     } else {
 933         throw new Error ('No XML support in this browser');
 934     }
 935
 936     return doc;
 937 }
 938
 939
 940 DOMDoc.parseXmlFromString = function ( xmlString )
 941 {
 942     var doc;
 943
 944     if ( window.DOMParser ) {
 945         var parser = new DOMParser();
 946         doc = parser.parseFromString( xmlString, "text/xml");
 947     } else if ( window.ActiveXObject ) {
 948         doc = new ActiveXObject("MSXML2.DOMDocument");
 949         doc.loadXML( xmlString );
 950     } else {
 951         throw new Error ("No XML parsing support in this browser.");
 952     }
 953
 954     return doc;
 955 }
 956
 957 DOMDoc.transformToDoc = function (xmlDoc, xslDoc)
 958 {
 959     if ( window.XSLTProcessor ) {
 960         var proc = new XSLTProcessor();
 961         proc.importStylesheet( xslDoc );
 962         return proc.transformToDocument(xmlDoc);
 963     } else if ( window.ActiveXObject ) {
 964         return document.parseXmlFromString(xmlDoc.transformNode(xslDoc));
 965     } else {
 966         alert( 'Unable to perform XSLT transformation in this browser' );
 967     }
 968 }
 969
 970 // DOMElement
 971
 972 Element_removeFromDoc = function (DOM_Element)
 973 {
 974     DOM_Element.parentNode.removeChild(DOM_Element);
 975 }
 976
 977 Element_emptyChildren = function (DOM_Element)
 978 {
 979     while( DOM_Element.firstChild ) {
 980         DOM_Element.removeChild( DOM_Element.firstChild )
 981     }
 982 }
 983
 984 Element_appendTransformResult = function ( DOM_Element, xmlDoc, xslDoc )
 985 {
 986     if ( window.XSLTProcessor ) {
 987         var proc = new XSLTProcessor();
 988         proc.importStylesheet( xslDoc );
 989         var docFrag = false;
 990         docFrag = proc.transformToFragment( xmlDoc, DOM_Element.ownerDocument );
 991         DOM_Element.appendChild(docFrag);
 992     } else if ( window.ActiveXObject ) {
 993         DOM_Element.innerHTML = xmlDoc.transformNode( xslDoc );
 994     } else {
 995         alert( 'Unable to perform XSLT transformation in this browser' );
 996     }
 997 }
 998
 999 Element_appendTextNode = function (DOM_Element, tagName, textContent )
1000 {
1001     var node = DOM_Element.ownerDocument.createElement(tagName);
1002     var text = DOM_Element.ownerDocument.createTextNode(textContent);
1003
1004     DOM_Element.appendChild(node);
1005     node.appendChild(text);
1006
1007     return node;
1008 }
1009
1010 Element_setTextContent = function ( DOM_Element, textContent )
1011 {
1012     if (typeof DOM_Element.textContent !== "undefined") {
1013         DOM_Element.textContent = textContent;
1014     } else if (typeof DOM_Element.innerText !== "undefined" ) {
1015         DOM_Element.innerText = textContent;
1016     } else {
1017         throw new Error("Cannot set text content of the node, no such method.");
1018     }
1019 }
1020
1021 Element_getTextContent = function (DOM_Element)
1022 {
1023     if ( typeof DOM_Element.textContent != 'undefined' ) {
1024         return DOM_Element.textContent;
1025     } else if (typeof DOM_Element.text != 'undefined') {
1026         return DOM_Element.text;
1027     } else {
1028         throw new Error("Cannot get text content of the node, no such method.");
1029     }
1030 }
1031
1032 Element_parseChildNodes = function (node)
1033 {
1034     var parsed = {};
1035     var hasChildElems = false;
1036
1037     if (node.hasChildNodes()) {
1038         var children = node.childNodes;
1039         for (var i = 0; i < children.length; i++) {
1040             var child = children[i];
1041             if (child.nodeType == Node.ELEMENT_NODE) {
1042                 hasChildElems = true;
1043                 var nodeName = child.nodeName;
1044                 if (!(nodeName in parsed))
1045                     parsed[nodeName] = [];
1046                 parsed[nodeName].push(Element_parseChildNodes(child));
1047             }
1048         }
1049     }
1050
1051     var attrs = node.attributes;
1052     for (var i = 0; i < attrs.length; i++) {
1053         var attrName = '@' + attrs[i].nodeName;
1054         var attrValue = attrs[i].nodeValue;
1055         parsed[attrName] = attrValue;
1056     }
1057
1058     // if no nested elements, get text content
1059     if (node.hasChildNodes() && !hasChildElems) {
1060         if (node.attributes.length)
1061             parsed['#text'] = node.firstChild.nodeValue;
1062         else
1063             parsed = node.firstChild.nodeValue;
1064     }
1065
1066     return parsed;
1067 }
1068
1069 /* do not remove trailing bracket */
1070 }