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     // Version parameter
 130     this.version = paramArray.version || null;
 131 };
 132
 133 pz2.prototype =
 134 {
 135     //error handler for async error throws
 136    throwError: function (errMsg, errCode)
 137    {
 138         var err = new Error(errMsg);
 139         if (errCode) err.code = errCode;
 140
 141         if (this.errorHandler) {
 142             this.errorHandler(err);
 143         }
 144         else {
 145             throw err;
 146         }
 147    },
 148
 149     // stop activity by clearing tiemouts
 150    stop: function ()
 151    {
 152        clearTimeout(this.statTimer);
 153        clearTimeout(this.showTimer);
 154        clearTimeout(this.termTimer);
 155        clearTimeout(this.bytargetTimer);
 156     },
 157
 158     // reset status variables
 159     reset: function ()
 160     {
 161         if ( this.useSessions ) {
 162             this.sessionID = null;
 163             this.initStatusOK = false;
 164             this.pingStatusOK = false;
 165             clearTimeout(this.pingTimer);
 166         }
 167         this.searchStatusOK = false;
 168         this.stop();
 169
 170         if ( this.resetCallback )
 171                 this.resetCallback();
 172     },
 173
 174     init: function (sessionId, serviceId)
 175     {
 176         this.reset();
 177
 178         // session id as a param
 179         if (sessionId && this.useSessions ) {
 180             this.initStatusOK = true;
 181             this.sessionID = sessionId;
 182             this.ping();
 183         // old school direct pazpar2 init
 184         } else if (this.useSessions) {
 185             var context = this;
 186             var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 187             var opts = {'command' : 'init'};
 188             if (serviceId) opts.service = serviceId;
 189             request.safeGet(
 190                 opts,
 191                 function(data) {
 192                     if ( data.getElementsByTagName("status")[0]
 193                             .childNodes[0].nodeValue == "OK" ) {
 194                         if ( data.getElementsByTagName("protocol")[0]
 195                                 .childNodes[0].nodeValue
 196                             != context.suppProtoVer )
 197                             throw new Error(
 198                                 "Server's protocol not supported by the client"
 199                             );
 200                         context.initStatusOK = true;
 201                         context.sessionID =
 202                             data.getElementsByTagName("session")[0]
 203                                 .childNodes[0].nodeValue;
 204                         context.pingTimer =
 205                             setTimeout(
 206                                 function () {
 207                                     context.ping();
 208                                 },
 209                                 context.keepAlive
 210                             );
 211                         if ( context.initCallback )
 212                             context.initCallback();
 213                     }
 214                     else
 215                         context.throwError('Init failed. Malformed WS resonse.',
 216                                             110);
 217                 }
 218             );
 219         // when through proxy no need to init
 220         } else {
 221             this.initStatusOK = true;
 222         }
 223     },
 224     // no need to ping explicitly
 225     ping: function ()
 226     {
 227         // pinging only makes sense when using pazpar2 directly
 228         if( !this.initStatusOK || !this.useSessions )
 229             throw new Error(
 230             'Pz2.js: Ping not allowed (proxy mode) or session not initialized.'
 231             );
 232         var context = this;
 233
 234         clearTimeout(context.pingTimer);
 235
 236         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 237         request.safeGet(
 238             { "command": "ping", "session": this.sessionID, "windowid" : window.name },
 239             function(data) {
 240                 if ( data.getElementsByTagName("status")[0]
 241                         .childNodes[0].nodeValue == "OK" ) {
 242                     context.pingStatusOK = true;
 243                     context.pingTimer =
 244                         setTimeout(
 245                             function () {
 246                                 context.ping();
 247                             },
 248                             context.keepAlive
 249                         );
 250                 }
 251                 else
 252                     context.throwError('Ping failed. Malformed WS resonse.',
 253                                         111);
 254             }
 255         );
 256     },
 257     search: function (query, num, sort, filter, showfrom, addParamsArr)
 258     {
 259         clearTimeout(this.statTimer);
 260         clearTimeout(this.showTimer);
 261         clearTimeout(this.termTimer);
 262         clearTimeout(this.bytargetTimer);
 263
 264         this.showCounter = 0;
 265         this.termCounter = 0;
 266         this.bytargetCounter = 0;
 267         this.statCounter = 0;
 268         this.activeClients = 1;
 269
 270         // no proxy mode
 271         if( !this.initStatusOK )
 272             throw new Error('Pz2.js: session not initialized.');
 273
 274         if( query !== undefined )
 275             this.currQuery = query;
 276         else
 277             throw new Error("Pz2.js: no query supplied to the search command.");
 278
 279         if ( showfrom !== undefined )
 280             var start = showfrom;
 281         else
 282             var start = 0;
 283
 284               var searchParams = {
 285           "command": "search",
 286           "query": this.currQuery,
 287           "session": this.sessionID,
 288           "windowid" : window.name
 289         };
 290
 291         if (filter !== undefined)
 292                 searchParams["filter"] = filter;
 293
 294         // copy additional parmeters, do not overwrite
 295         if (addParamsArr != undefined) {
 296             for (var prop in addParamsArr) {
 297                 if (!searchParams.hasOwnProperty(prop))
 298                     searchParams[prop] = addParamsArr[prop];
 299             }
 300         }
 301
 302         var context = this;
 303         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 304         request.safeGet(
 305             searchParams,
 306             function(data) {
 307                 if ( data.getElementsByTagName("status")[0]
 308                         .childNodes[0].nodeValue == "OK" ) {
 309                     context.searchStatusOK = true;
 310                     //piggyback search
 311                     context.show(start, num, sort);
 312                     if (context.statCallback)
 313                         context.stat();
 314                     if (context.termlistCallback)
 315                         context.termlist();
 316                     if (context.bytargetCallback)
 317                         context.bytarget();
 318                 }
 319                 else
 320                     context.throwError('Search failed. Malformed WS resonse.',
 321                                         112);
 322             }
 323         );
 324     },
 325     stat: function()
 326     {
 327         if( !this.initStatusOK )
 328             throw new Error('Pz2.js: session not initialized.');
 329
 330         // if called explicitly takes precedence
 331         clearTimeout(this.statTimer);
 332
 333         var context = this;
 334         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 335         request.safeGet(
 336             { "command": "stat", "session": this.sessionID, "windowid" : window.name },
 337             function(data) {
 338                 if ( data.getElementsByTagName("stat") ) {
 339                     var activeClients =
 340                         Number( data.getElementsByTagName("activeclients")[0]
 341                                     .childNodes[0].nodeValue );
 342                     context.activeClients = activeClients;
 343
 344                     var stat = Element_parseChildNodes(data.documentElement);
 345
 346                     context.statCounter++;
 347                     var delay = context.statTime
 348                         + context.statCounter * context.dumpFactor;
 349
 350                     if ( activeClients > 0 )
 351                         context.statTimer =
 352                             setTimeout(
 353                                 function () {
 354                                     context.stat();
 355                                 },
 356                                 delay
 357                             );
 358                     context.statCallback(stat);
 359                 }
 360                 else
 361                     context.throwError('Stat failed. Malformed WS resonse.',
 362                                         113);
 363             }
 364         );
 365     },
 366     show: function(start, num, sort, query_state)
 367     {
 368         if( !this.searchStatusOK && this.useSessions )
 369             throw new Error(
 370                 'Pz2.js: show command has to be preceded with a search command.'
 371             );
 372
 373         // if called explicitly takes precedence
 374         clearTimeout(this.showTimer);
 375
 376         if( sort !== undefined )
 377             this.currentSort = sort;
 378         if( start !== undefined )
 379             this.currentStart = Number( start );
 380         if( num !== undefined )
 381             this.currentNum = Number( num );
 382
 383         var context = this;
 384         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 385         var requestParameters =
 386           {
 387               "command": "show",
 388               "session": this.sessionID,
 389               "start": this.currentStart,
 390               "num": this.currentNum,
 391               "sort": this.currentSort,
 392               "block": 1,
 393               "type": this.showResponseType,
 394               "windowid" : window.name,
 395           };
 396         if (query_state)
 397           requestParameters["query-state"] = query_state;
 398         if (this.version && this.version > 0)
 399             requestParameters["version"] = this.version;
 400         request.safeGet(
 401           requestParameters,
 402           function(data, type) {
 403             var show = null;
 404             var activeClients = 0;
 405             if (type === "json") {
 406               show = {};
 407               activeClients = Number(data.activeclients[0]);
 408               show.activeclients = activeClients;
 409               show.merged = Number(data.merged[0]);
 410               show.total = Number(data.total[0]);
 411               show.start = Number(data.start[0]);
 412               show.num = Number(data.num[0]);
 413               show.hits = data.hit;
 414             } else if (data.getElementsByTagName("status")[0]
 415                   .childNodes[0].nodeValue == "OK") {
 416                 // first parse the status data send along with records
 417                 // this is strictly bound to the format
 418                 activeClients =
 419                   Number(data.getElementsByTagName("activeclients")[0]
 420                       .childNodes[0].nodeValue);
 421                 show = {
 422                   "activeclients": activeClients,
 423                   "merged":
 424                     Number( data.getElementsByTagName("merged")[0]
 425                         .childNodes[0].nodeValue ),
 426                   "total":
 427                     Number( data.getElementsByTagName("total")[0]
 428                         .childNodes[0].nodeValue ),
 429                   "start":
 430                     Number( data.getElementsByTagName("start")[0]
 431                         .childNodes[0].nodeValue ),
 432                   "num":
 433                     Number( data.getElementsByTagName("num")[0]
 434                         .childNodes[0].nodeValue ),
 435                   "hits": []
 436                 };
 437                 // parse all the first-level nodes for all <hit> tags
 438                 var hits = data.getElementsByTagName("hit");
 439                 for (i = 0; i < hits.length; i++)
 440                   show.hits[i] = Element_parseChildNodes(hits[i]);
 441             } else {
 442               context.throwError('Show failed. Malformed WS resonse.',
 443                   114);
 444             };
 445             var approxNode = data.getElementsByTagName("approximation");
 446             if (approxNode)
 447                 show['approximation'] =
 448                   Number( approxNode[0].childNodes[0].nodeValue);
 449
 450
 451               data.getElementsByTagName("")
 452             context.activeClients = activeClients;
 453             context.showCounter++;
 454             var delay = context.showTime;
 455             if (context.showCounter > context.showFastCount)
 456               delay += context.showCounter * context.dumpFactor;
 457             if ( activeClients > 0 )
 458               context.showTimer = setTimeout(
 459                 function () {
 460                   context.show();
 461                 },
 462                 delay);
 463             context.showCallback(show);
 464           }
 465         );
 466     },
 467     record: function(id, offset, syntax, handler)
 468     {
 469         // we may call record with no previous search if in proxy mode
 470         if(!this.searchStatusOK && this.useSessions)
 471            throw new Error(
 472             'Pz2.js: record command has to be preceded with a search command.'
 473             );
 474
 475         if( id !== undefined )
 476             this.currRecID = id;
 477
 478         var recordParams = {
 479             "command": "record",
 480             "session": this.sessionID,
 481             "id": this.currRecID,
 482             "windowid" : window.name
 483         };
 484
 485         this.currRecOffset = null;
 486         if (offset != undefined) {
 487             recordParams["offset"] = offset;
 488             this.currRecOffset = offset;
 489         }
 490
 491         if (syntax != undefined)
 492             recordParams['syntax'] = syntax;
 493
 494         //overwrite default callback id needed
 495         var callback = this.recordCallback;
 496         var args = undefined;
 497         if (handler != undefined) {
 498             callback = handler['callback'];
 499             args = handler['args'];
 500         }
 501
 502         var context = this;
 503         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 504
 505         request.safeGet(
 506             recordParams,
 507             function(data) {
 508                 var recordNode;
 509                 var record;
 510                 //raw record
 511                 if (context.currRecOffset !== null) {
 512                     record = new Array();
 513                     record['xmlDoc'] = data;
 514                     record['offset'] = context.currRecOffset;
 515                     callback(record, args);
 516                 //pz2 record
 517                 } else if ( recordNode =
 518                     data.getElementsByTagName("record")[0] ) {
 519                     // if stylesheet was fetched do not parse the response
 520                     if ( context.xslDoc ) {
 521                         record = new Array();
 522                         record['xmlDoc'] = data;
 523                         record['xslDoc'] = context.xslDoc;
 524                         record['recid'] =
 525                             recordNode.getElementsByTagName("recid")[0]
 526                                 .firstChild.nodeValue;
 527                     //parse record
 528                     } else {
 529                         record = Element_parseChildNodes(recordNode);
 530                     }
 531                     var activeClients =
 532                        Number( data.getElementsByTagName("activeclients")[0]
 533                                 .childNodes[0].nodeValue );
 534                     context.activeClients = activeClients;
 535                     context.recordCounter++;
 536                     var delay = context.recordTime + context.recordCounter * context.dumpFactor;
 537                     if ( activeClients > 0 )
 538                         context.recordTimer =
 539                            setTimeout (
 540                                function() {
 541                                   context.record(id, offset, syntax, handler);
 542                                   },
 543                                   delay
 544                                );
 545                     callback(record, args);
 546                 }
 547                 else
 548                     context.throwError('Record failed. Malformed WS resonse.',
 549                                         115);
 550             }
 551         );
 552     },
 553
 554     termlist: function()
 555     {
 556         if( !this.searchStatusOK && this.useSessions )
 557             throw new Error(
 558             'Pz2.js: termlist command has to be preceded with a search command.'
 559             );
 560
 561         // if called explicitly takes precedence
 562         clearTimeout(this.termTimer);
 563
 564         var context = this;
 565         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 566         request.safeGet(
 567             {
 568                 "command": "termlist",
 569                 "session": this.sessionID,
 570                 "name": this.termKeys,
 571                 "windowid" : window.name,
 572                 "version" : this.version
 573
 574             },
 575             function(data) {
 576                 if ( data.getElementsByTagName("termlist") ) {
 577                     var activeClients =
 578                         Number( data.getElementsByTagName("activeclients")[0]
 579                                     .childNodes[0].nodeValue );
 580                     context.activeClients = activeClients;
 581                     var termList = { "activeclients":  activeClients };
 582                     var termLists = data.getElementsByTagName("list");
 583                     //for each termlist
 584                     for (i = 0; i < termLists.length; i++) {
 585                         var listName = termLists[i].getAttribute('name');
 586                         termList[listName] = new Array();
 587                         var terms = termLists[i].getElementsByTagName('term');
 588                         //for each term in the list
 589                         for (j = 0; j < terms.length; j++) {
 590                             var term = {
 591                                 "name":
 592                                     (terms[j].getElementsByTagName("name")[0]
 593                                         .childNodes.length
 594                                     ? terms[j].getElementsByTagName("name")[0]
 595                                         .childNodes[0].nodeValue
 596                                     : 'ERROR'),
 597                                 "freq":
 598                                     terms[j]
 599                                     .getElementsByTagName("frequency")[0]
 600                                     .childNodes[0].nodeValue || 'ERROR'
 601                             };
 602
 603                             // Only for xtargets: id, records, filtered
 604                             var termIdNode =
 605                                 terms[j].getElementsByTagName("id");
 606                             if(terms[j].getElementsByTagName("id").length)
 607                                 term["id"] =
 608                                     termIdNode[0].childNodes[0].nodeValue;
 609                             termList[listName][j] = term;
 610
 611                             var recordsNode  = terms[j].getElementsByTagName("records");
 612                             if (recordsNode && recordsNode.length)
 613                                 term["records"] = recordsNode[0].childNodes[0].nodeValue;
 614
 615                             var filteredNode  = terms[j].getElementsByTagName("filtered");
 616                             if (filteredNode && filteredNode.length)
 617                                 term["filtered"] = filteredNode[0].childNodes[0].nodeValue;
 618
 619                         }
 620                     }
 621
 622                     context.termCounter++;
 623                     var delay = context.termTime
 624                         + context.termCounter * context.dumpFactor;
 625                     if ( activeClients > 0 )
 626                         context.termTimer =
 627                             setTimeout(
 628                                 function () {
 629                                     context.termlist();
 630                                 },
 631                                 delay
 632                             );
 633
 634                    context.termlistCallback(termList);
 635                 }
 636                 else
 637                     context.throwError('Termlist failed. Malformed WS resonse.',
 638                                         116);
 639             }
 640         );
 641
 642     },
 643     bytarget: function()
 644     {
 645         if( !this.initStatusOK && this.useSessions )
 646             throw new Error(
 647             'Pz2.js: bytarget command has to be preceded with a search command.'
 648             );
 649
 650         // no need to continue
 651         if( !this.searchStatusOK )
 652             return;
 653
 654         // if called explicitly takes precedence
 655         clearTimeout(this.bytargetTimer);
 656
 657         var context = this;
 658         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 659         request.safeGet(
 660             {
 661                 "command": "bytarget",
 662                 "session": this.sessionID,
 663                 "block": 1,
 664                 "windowid" : window.name,
 665                 "version" : this.version
 666             },
 667             function(data) {
 668                 if ( data.getElementsByTagName("status")[0]
 669                         .childNodes[0].nodeValue == "OK" ) {
 670                     var targetNodes = data.getElementsByTagName("target");
 671                     var bytarget = new Array();
 672                     for ( i = 0; i < targetNodes.length; i++) {
 673                         bytarget[i] = new Array();
 674                         for( j = 0; j < targetNodes[i].childNodes.length; j++ ) {
 675                             if ( targetNodes[i].childNodes[j].nodeType
 676                                 == Node.ELEMENT_NODE ) {
 677                                 var nodeName =
 678                                     targetNodes[i].childNodes[j].nodeName;
 679                                 if (targetNodes[i].childNodes[j].firstChild != null)
 680                                 {
 681                                     var nodeText = targetNodes[i].childNodes[j]
 682                                         .firstChild.nodeValue;
 683                                     bytarget[i][nodeName] = nodeText;
 684                                 }
 685                                 else {
 686                                     bytarget[i][nodeName] = "";
 687                                 }
 688
 689
 690                             }
 691                         }
 692                         if (bytarget[i]["state"]=="Client_Disconnected") {
 693                           bytarget[i]["hits"] = "Error";
 694                         } else if (bytarget[i]["state"]=="Client_Error") {
 695                           bytarget[i]["hits"] = "Error";
 696                         } else if (bytarget[i]["state"]=="Client_Working") {
 697                           bytarget[i]["hits"] = "...";
 698                         }
 699                         if (bytarget[i].diagnostic == "1") {
 700                           bytarget[i].diagnostic = "Permanent system error";
 701                         } else if (bytarget[i].diagnostic == "2") {
 702                           bytarget[i].diagnostic = "Temporary system error";
 703                         }
 704                         var targetsSuggestions = targetNodes[i].getElementsByTagName("suggestions");
 705                         if (targetsSuggestions != undefined && targetsSuggestions.length>0) {
 706                           var suggestions = targetsSuggestions[0];
 707                           bytarget[i]["suggestions"] = Element_parseChildNodes(suggestions);
 708                         }
 709                     }
 710
 711                     context.bytargetCounter++;
 712                     var delay = context.bytargetTime
 713                         + context.bytargetCounter * context.dumpFactor;
 714                     if ( context.activeClients > 0 )
 715                         context.bytargetTimer =
 716                             setTimeout(
 717                                 function () {
 718                                     context.bytarget();
 719                                 },
 720                                 delay
 721                             );
 722
 723                     context.bytargetCallback(bytarget);
 724                 }
 725                 else
 726                     context.throwError('Bytarget failed. Malformed WS resonse.',
 727                                         117);
 728             }
 729         );
 730     },
 731
 732     // just for testing, probably shouldn't be here
 733     showNext: function(page)
 734     {
 735         var step = page || 1;
 736         this.show( ( step * this.currentNum ) + this.currentStart );
 737     },
 738
 739     showPrev: function(page)
 740     {
 741         if (this.currentStart == 0 )
 742             return false;
 743         var step = page || 1;
 744         var newStart = this.currentStart - (step * this.currentNum );
 745         this.show( newStart > 0 ? newStart : 0 );
 746     },
 747
 748     showPage: function(pageNum)
 749     {
 750         //var page = pageNum || 1;
 751         this.show(pageNum * this.currentNum);
 752     }
 753 };
 754
 755 /*
 756 ********************************************************************************
 757 ** AJAX HELPER CLASS ***********************************************************
 758 ********************************************************************************
 759 */
 760 var pzHttpRequest = function ( url, errorHandler ) {
 761         this.maxUrlLength = 2048;
 762         this.request = null;
 763         this.url = url;
 764         this.errorHandler = errorHandler || null;
 765         this.async = true;
 766         this.requestHeaders = {};
 767
 768         if ( window.XMLHttpRequest ) {
 769             this.request = new XMLHttpRequest();
 770         } else if ( window.ActiveXObject ) {
 771             try {
 772                 this.request = new ActiveXObject( 'Msxml2.XMLHTTP' );
 773             } catch (err) {
 774                 this.request = new ActiveXObject( 'Microsoft.XMLHTTP' );
 775             }
 776         }
 777 };
 778
 779
 780 pzHttpRequest.prototype =
 781 {
 782     safeGet: function ( params, callback )
 783     {
 784         var encodedParams =  this.encodeParams(params);
 785         var url = this._urlAppendParams(encodedParams);
 786         if (url.length >= this.maxUrlLength) {
 787             this.requestHeaders["Content-Type"]
 788                 = "application/x-www-form-urlencoded";
 789             this._send( 'POST', this.url, encodedParams, callback );
 790         } else {
 791             this._send( 'GET', url, '', callback );
 792         }
 793     },
 794
 795     get: function ( params, callback )
 796     {
 797         this._send( 'GET', this._urlAppendParams(this.encodeParams(params)),
 798             '', callback );
 799     },
 800
 801     post: function ( params, data, callback )
 802     {
 803         this._send( 'POST', this._urlAppendParams(this.encodeParams(params)),
 804             data, callback );
 805     },
 806
 807     load: function ()
 808     {
 809         this.async = false;
 810         this.request.open( 'GET', this.url, this.async );
 811         this.request.send('');
 812         if ( this.request.status == 200 )
 813             return this.request.responseXML;
 814     },
 815
 816     encodeParams: function (params)
 817     {
 818         var sep = "";
 819         var encoded = "";
 820         for (var key in params) {
 821             if (params[key] != null) {
 822                 encoded += sep + key + '=' + encodeURIComponent(params[key]);
 823                 sep = '&';
 824             }
 825         }
 826         return encoded;
 827     },
 828
 829     _send: function ( type, url, data, callback)
 830     {
 831         var context = this;
 832         this.callback = callback;
 833         this.async = true;
 834         this.request.open( type, url, this.async );
 835         for (var key in this.requestHeaders)
 836             this.request.setRequestHeader(key, this.requestHeaders[key]);
 837         this.request.onreadystatechange = function () {
 838             context._handleResponse(url); /// url used ONLY for error reporting
 839         }
 840         this.request.send(data);
 841     },
 842
 843     _urlAppendParams: function (encodedParams)
 844     {
 845         if (encodedParams)
 846             return this.url + "?" + encodedParams;
 847         else
 848             return this.url;
 849     },
 850
 851     _handleResponse: function (savedUrlForErrorReporting)
 852     {
 853         if ( this.request.readyState == 4 ) {
 854             // pick up appplication errors first
 855             var errNode = null;
 856             if (this.request.responseXML &&
 857                 (errNode = this.request.responseXML.documentElement)
 858                 && errNode.nodeName == 'error') {
 859                 var errMsg = errNode.getAttribute("msg");
 860                 var errCode = errNode.getAttribute("code");
 861                 var errAddInfo = '';
 862                 if (errNode.childNodes.length)
 863                     errAddInfo = ': ' + errNode.childNodes[0].nodeValue;
 864
 865                 var err = new Error(errMsg + errAddInfo);
 866                 err.code = errCode;
 867
 868                 if (this.errorHandler) {
 869                     this.errorHandler(err);
 870                 }
 871                 else {
 872                     throw err;
 873                 }
 874             } else if (this.request.status == 200 &&
 875                        this.request.responseXML == null) {
 876               if (this.request.responseText != null) {
 877                 //assume JSON
 878
 879                 var json = null;
 880                 var text = this.request.responseText;
 881                 if (typeof window.JSON == "undefined")
 882                     json = eval("(" + text + ")");
 883                 else {
 884                     try {
 885                         json = JSON.parse(text);
 886                     }
 887                     catch (e) {
 888                         // Safari: eval will fail as well. Considering trying JSON2 (non-native implementation) instead
 889                         /* DEBUG only works in mk2-mobile
 890                         if (document.getElementById("log"))
 891                             document.getElementById("log").innerHTML = "" + e + " " + length + ": " + text;
 892                         */
 893                         try {
 894                             json = eval("(" + text + ")");
 895                         }
 896                         catch (e) {
 897                             /* DEBUG only works in mk2-mobile
 898                             if (document.getElementById("log"))
 899                                 document.getElementById("log").innerHTML = "" + e + " " + length + ": " + text;
 900                             */
 901                         }
 902                     }
 903                 }
 904                 this.callback(json, "json");
 905               } else {
 906                 var err = new Error("XML response is empty but no error " +
 907                                     "for " + savedUrlForErrorReporting);
 908                 err.code = -1;
 909                 if (this.errorHandler) {
 910                     this.errorHandler(err);
 911                 } else {
 912                     throw err;
 913                 }
 914               }
 915             } else if (this.request.status == 200) {
 916                 this.callback(this.request.responseXML);
 917             } else {
 918                 var err = new Error("HTTP response not OK: "
 919                             + this.request.status + " - "
 920                             + this.request.statusText );
 921                 err.code = '00' + this.request.status;
 922                 if (this.errorHandler) {
 923                     this.errorHandler(err);
 924                 }
 925                 else {
 926                     throw err;
 927                 }
 928             }
 929         }
 930     }
 931 };
 932
 933 /*
 934 ********************************************************************************
 935 ** XML HELPER FUNCTIONS ********************************************************
 936 ********************************************************************************
 937 */
 938
 939 // DOMDocument
 940
 941 if ( window.ActiveXObject) {
 942     var DOMDoc = document;
 943 } else {
 944     var DOMDoc = Document.prototype;
 945 }
 946
 947 DOMDoc.newXmlDoc = function ( root )
 948 {
 949     var doc;
 950
 951     if (document.implementation && document.implementation.createDocument) {
 952         doc = document.implementation.createDocument('', root, null);
 953     } else if ( window.ActiveXObject ) {
 954         doc = new ActiveXObject("MSXML2.DOMDocument");
 955         doc.loadXML('<' + root + '/>');
 956     } else {
 957         throw new Error ('No XML support in this browser');
 958     }
 959
 960     return doc;
 961 }
 962
 963
 964 DOMDoc.parseXmlFromString = function ( xmlString )
 965 {
 966     var doc;
 967
 968     if ( window.DOMParser ) {
 969         var parser = new DOMParser();
 970         doc = parser.parseFromString( xmlString, "text/xml");
 971     } else if ( window.ActiveXObject ) {
 972         doc = new ActiveXObject("MSXML2.DOMDocument");
 973         doc.loadXML( xmlString );
 974     } else {
 975         throw new Error ("No XML parsing support in this browser.");
 976     }
 977
 978     return doc;
 979 }
 980
 981 DOMDoc.transformToDoc = function (xmlDoc, xslDoc)
 982 {
 983     if ( window.XSLTProcessor ) {
 984         var proc = new XSLTProcessor();
 985         proc.importStylesheet( xslDoc );
 986         return proc.transformToDocument(xmlDoc);
 987     } else if ( window.ActiveXObject ) {
 988         return document.parseXmlFromString(xmlDoc.transformNode(xslDoc));
 989     } else {
 990         alert( 'Unable to perform XSLT transformation in this browser' );
 991     }
 992 }
 993
 994 // DOMElement
 995
 996 Element_removeFromDoc = function (DOM_Element)
 997 {
 998     DOM_Element.parentNode.removeChild(DOM_Element);
 999 }
1000
1001 Element_emptyChildren = function (DOM_Element)
1002 {
1003     while( DOM_Element.firstChild ) {
1004         DOM_Element.removeChild( DOM_Element.firstChild )
1005     }
1006 }
1007
1008 Element_appendTransformResult = function ( DOM_Element, xmlDoc, xslDoc )
1009 {
1010     if ( window.XSLTProcessor ) {
1011         var proc = new XSLTProcessor();
1012         proc.importStylesheet( xslDoc );
1013         var docFrag = false;
1014         docFrag = proc.transformToFragment( xmlDoc, DOM_Element.ownerDocument );
1015         DOM_Element.appendChild(docFrag);
1016     } else if ( window.ActiveXObject ) {
1017         DOM_Element.innerHTML = xmlDoc.transformNode( xslDoc );
1018     } else {
1019         alert( 'Unable to perform XSLT transformation in this browser' );
1020     }
1021 }
1022
1023 Element_appendTextNode = function (DOM_Element, tagName, textContent )
1024 {
1025     var node = DOM_Element.ownerDocument.createElement(tagName);
1026     var text = DOM_Element.ownerDocument.createTextNode(textContent);
1027
1028     DOM_Element.appendChild(node);
1029     node.appendChild(text);
1030
1031     return node;
1032 }
1033
1034 Element_setTextContent = function ( DOM_Element, textContent )
1035 {
1036     if (typeof DOM_Element.textContent !== "undefined") {
1037         DOM_Element.textContent = textContent;
1038     } else if (typeof DOM_Element.innerText !== "undefined" ) {
1039         DOM_Element.innerText = textContent;
1040     } else {
1041         throw new Error("Cannot set text content of the node, no such method.");
1042     }
1043 }
1044
1045 Element_getTextContent = function (DOM_Element)
1046 {
1047     if ( typeof DOM_Element.textContent != 'undefined' ) {
1048         return DOM_Element.textContent;
1049     } else if (typeof DOM_Element.text != 'undefined') {
1050         return DOM_Element.text;
1051     } else {
1052         throw new Error("Cannot get text content of the node, no such method.");
1053     }
1054 }
1055
1056 Element_parseChildNodes = function (node)
1057 {
1058     var parsed = {};
1059     var hasChildElems = false;
1060
1061     if (node.hasChildNodes()) {
1062         var children = node.childNodes;
1063         for (var i = 0; i < children.length; i++) {
1064             var child = children[i];
1065             if (child.nodeType == Node.ELEMENT_NODE) {
1066                 hasChildElems = true;
1067                 var nodeName = child.nodeName;
1068                 if (!(nodeName in parsed))
1069                     parsed[nodeName] = [];
1070                 parsed[nodeName].push(Element_parseChildNodes(child));
1071             }
1072         }
1073     }
1074
1075     var attrs = node.attributes;
1076     for (var i = 0; i < attrs.length; i++) {
1077         var attrName = '@' + attrs[i].nodeName;
1078         var attrValue = attrs[i].nodeValue;
1079         parsed[attrName] = attrValue;
1080     }
1081
1082     // if no nested elements, get text content
1083     if (node.hasChildNodes() && !hasChildElems) {
1084         if (node.attributes.length)
1085             parsed['#text'] = node.firstChild.nodeValue;
1086         else
1087             parsed = node.firstChild.nodeValue;
1088     }
1089
1090     return parsed;
1091 }
1092
1093 /* do not remove trailing bracket */
1094 }