js/pz2.js

   1 /*
   2 ** $Id: pz2.js,v 1.61 2007-10-02 11:47:50 jakub Exp $
   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: An array with parameters has to be suplied when instantiating a class");
  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
  52     // function callbacks
  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     //timers
  88     this.statTime = paramArray.stattime || 1000;
  89     this.statTimer = null;
  90     this.termTime = paramArray.termtime || 1000;
  91     this.termTimer = null;
  92     this.showTime = paramArray.showtime || 1000;
  93     this.showTimer = null;
  94     this.showFastCount = 4;
  95     this.bytargetTime = paramArray.bytargettime || 1000;
  96     this.bytargetTimer = null;
  97
  98     // counters for each command and applied delay
  99     this.dumpFactor = 500;
 100     this.showCounter = 0;
 101     this.termCounter = 0;
 102     this.statCounter = 0;
 103     this.bytargetCounter = 0;
 104
 105     // active clients, updated by stat and show
 106     // might be an issue since bytarget will poll accordingly
 107     this.activeClients = 1;
 108
 109     // if in proxy mode no need to init
 110     if (paramArray.usesessions != undefined) {
 111          this.useSessions = paramArray.usesessions;
 112         this.initStatusOK = true;
 113     }
 114     // else, auto init session or wait for a user init?
 115     if (this.useSessions && paramArray.autoInit !== false) {
 116         this.init();
 117     }
 118 };
 119
 120 pz2.prototype =
 121 {
 122     //error handler for async error throws
 123    throwError: function (errMsg, errCode)
 124    {
 125         var err = new Error(errMsg);
 126         if (errCode) err.code = errCode;
 127
 128         if (this.errorHandler) {
 129             this.errorHandler(err);
 130         }
 131         else {
 132             throw err;
 133         }
 134    },
 135
 136     // stop activity by clearing tiemouts
 137    stop: function ()
 138    {
 139        clearTimeout(this.statTimer);
 140        clearTimeout(this.showTimer);
 141        clearTimeout(this.termTimer);
 142        clearTimeout(this.bytargetTimer);
 143     },
 144
 145     // reset status variables
 146     reset: function ()
 147     {
 148         if ( this.useSessions ) {
 149             this.sessionID = null;
 150             this.initStatusOK = false;
 151             this.pingStatusOK = false;
 152         }
 153         this.searchStatusOK = false;
 154         this.stop();
 155
 156         if ( this.resetCallback )
 157                 this.resetCallback();
 158     },
 159
 160     init: function ( sessionId )
 161     {
 162         this.reset();
 163
 164         // session id as a param
 165         if ( sessionId != undefined && this.useSessions ) {
 166             this.initStatusOK = true;
 167             this.sessionID = sessionId;
 168             this.ping();
 169         // old school direct pazpar2 init
 170         } else if (this.useSessions) {
 171             var context = this;
 172             var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 173             request.get(
 174                 { "command": "init" },
 175                 function(data) {
 176                     if ( data.getElementsByTagName("status")[0]
 177                             .childNodes[0].nodeValue == "OK" ) {
 178                         if ( data.getElementsByTagName("protocol")[0]
 179                                 .childNodes[0].nodeValue
 180                             != context.suppProtoVer )
 181                             throw new Error("Server's protocol not supported by the client");
 182                         context.initStatusOK = true;
 183                         context.sessionID =
 184                             data.getElementsByTagName("session")[0]
 185                                 .childNodes[0].nodeValue;
 186                         setTimeout(
 187                             function () {
 188                                 context.ping();
 189                             },
 190                             context.keepAlive
 191                         );
 192                     }
 193                     else
 194                         context.throwError('Init failed. Malformed WS resonse.',
 195                                             110);
 196                 }
 197             );
 198         // when through proxy no need to init
 199         } else {
 200             this.initStatusOK = true;
 201         }
 202     },
 203     // no need to ping explicitly
 204     ping: function ()
 205     {
 206         // pinging only makes sense when using pazpar2 directly
 207         if( !this.initStatusOK || !this.useSessions )
 208             throw new Error('Pz2.js: Ping not allowed (proxy mode) or session not initialized.');
 209             // session is not initialized code here
 210
 211         var context = this;
 212         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 213         request.get(
 214             { "command": "ping", "session": this.sessionID },
 215             function(data) {
 216                 if ( data.getElementsByTagName("status")[0]
 217                         .childNodes[0].nodeValue == "OK" ) {
 218                     context.pingStatusOK = true;
 219                     setTimeout(
 220                         function () {
 221                             context.ping();
 222                         },
 223                         context.keepAlive
 224                     );
 225                 }
 226                 else
 227                     context.throwError('Ping failed. Malformed WS resonse.',
 228                                         111);
 229             }
 230         );
 231     },
 232     search: function (query, num, sort, filter, showfrom)
 233     {
 234         clearTimeout(this.statTimer);
 235         clearTimeout(this.showTimer);
 236         clearTimeout(this.termTimer);
 237         clearTimeout(this.bytargetTimer);
 238
 239         this.showCounter = 0;
 240         this.termCounter = 0;
 241         this.bytargetCounter = 0;
 242         this.statCounter = 0;
 243
 244         // no proxy mode
 245         if( !this.initStatusOK )
 246             throw new Error('Pz2.js: session not initialized.');
 247
 248         if( query !== undefined )
 249             this.currQuery = query;
 250         else
 251             throw new Error("Pz2.js: no query supplied to the search command.");
 252
 253         if ( showfrom !== undefined )
 254             var start = showfrom;
 255         else
 256             var start = 0;
 257
 258         var searchParams = {
 259             "command": "search",
 260             "query": this.currQuery,
 261             "session": this.sessionID
 262         };
 263
 264         if (filter !== undefined)
 265             searchParams["filter"] = filter;
 266
 267         var context = this;
 268         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 269         request.get(
 270             searchParams,
 271             function(data) {
 272                 if ( data.getElementsByTagName("status")[0]
 273                         .childNodes[0].nodeValue == "OK" ) {
 274                     context.searchStatusOK = true;
 275                     //piggyback search
 276                     context.show(start, num, sort);
 277                     if ( context.statCallback )
 278                         context.stat();
 279                     if ( context.termlistCallback )
 280                         context.termlist();
 281                     if ( context.bytargetCallback )
 282                         context.bytarget();
 283                 }
 284                 else
 285                     context.throwError('Search failed. Malformed WS resonse.',
 286                                         112);
 287             }
 288         );
 289     },
 290     stat: function()
 291     {
 292         if( !this.initStatusOK )
 293             throw new Error('Pz2.js: session not initialized.');
 294
 295         // if called explicitly takes precedence
 296         clearTimeout(this.statTimer);
 297
 298         var context = this;
 299         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 300         request.get(
 301             { "command": "stat", "session": this.sessionID },
 302             function(data) {
 303                 if ( data.getElementsByTagName("stat") ) {
 304                     var activeClients =
 305                         Number( data.getElementsByTagName("activeclients")[0]
 306                                     .childNodes[0].nodeValue );
 307                     context.activeClients = activeClients;
 308                     var stat = {
 309                         "activeclients": activeClients,
 310                         "hits":
 311                             Number( data.getElementsByTagName("hits")[0]
 312                                         .childNodes[0].nodeValue ),
 313                         "records":
 314                             Number( data.getElementsByTagName("records")[0]
 315                                         .childNodes[0].nodeValue ),
 316                         "clients":
 317                             Number( data.getElementsByTagName("clients")[0]
 318                                         .childNodes[0].nodeValue ),
 319                         "initializing":
 320                             Number( data.getElementsByTagName("initializing")[0]
 321                                         .childNodes[0].nodeValue ),
 322                         "searching":
 323                             Number( data.getElementsByTagName("searching")[0]
 324                                         .childNodes[0].nodeValue ),
 325                         "presenting":
 326                             Number( data.getElementsByTagName("presenting")[0]
 327                                         .childNodes[0].nodeValue ),
 328                         "idle":
 329                             Number( data.getElementsByTagName("idle")[0]
 330                                         .childNodes[0].nodeValue ),
 331                         "failed":
 332                             Number( data.getElementsByTagName("failed")[0]
 333                                         .childNodes[0].nodeValue ),
 334                         "error":
 335                             Number( data.getElementsByTagName("error")[0]
 336                                         .childNodes[0].nodeValue )
 337                     };
 338
 339                     context.statCounter++;
 340                     var delay = context.statTime
 341                         + context.statCounter * context.dumpFactor;
 342
 343                     if ( activeClients > 0 )
 344                         context.statTimer =
 345                             setTimeout(
 346                                 function () {
 347                                     context.stat();
 348                                 },
 349                                 delay
 350                             );
 351                     context.statCallback(stat);
 352                 }
 353                 else
 354                     context.throwError('Stat failed. Malformed WS resonse.',
 355                                         113);
 356             }
 357         );
 358     },
 359     show: function(start, num, sort)
 360     {
 361         if( !this.searchStatusOK && this.useSessions )
 362             throw new Error('Pz2.js: show command has to be preceded with a search command.');
 363
 364         // if called explicitly takes precedence
 365         clearTimeout(this.showTimer);
 366
 367         if( sort !== undefined )
 368             this.currentSort = sort;
 369         if( start !== undefined )
 370             this.currentStart = Number( start );
 371         if( num !== undefined )
 372             this.currentNum = Number( num );
 373
 374         var context = this;
 375         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 376         request.get(
 377             {
 378                 "command": "show",
 379                 "session": this.sessionID,
 380                 "start": this.currentStart,
 381                 "num": this.currentNum,
 382                 "sort": this.currentSort,
 383                 "block": 1
 384             },
 385             function(data) {
 386                 if ( data.getElementsByTagName("status")[0]
 387                         .childNodes[0].nodeValue == "OK" ) {
 388                     // first parse the status data send along with records
 389                     // this is strictly bound to the format
 390                     var activeClients =
 391                         Number( data.getElementsByTagName("activeclients")[0]
 392                                     .childNodes[0].nodeValue );
 393                     context.activeClients = activeClients;
 394                     var show = {
 395                         "activeclients": activeClients,
 396                         "merged":
 397                             Number( data.getElementsByTagName("merged")[0]
 398                                         .childNodes[0].nodeValue ),
 399                         "total":
 400                             Number( data.getElementsByTagName("total")[0]
 401                                         .childNodes[0].nodeValue ),
 402                         "start":
 403                             Number( data.getElementsByTagName("start")[0]
 404                                         .childNodes[0].nodeValue ),
 405                         "num":
 406                             Number( data.getElementsByTagName("num")[0]
 407                                         .childNodes[0].nodeValue ),
 408                         "hits": []
 409                     };
 410                     // parse all the first-level nodes for all <hit> tags
 411                     var hits = data.getElementsByTagName("hit");
 412                     var hit = new Array();
 413                     for (i = 0; i < hits.length; i++) {
 414                         show.hits[i] = new Array();
 415                         show.hits[i]['location'] = new Array();
 416                         for ( j = 0; j < hits[i].childNodes.length; j++) {
 417                             var locCount = 0;
 418                             if ( hits[i].childNodes[j].nodeType
 419                                 == Node.ELEMENT_NODE ) {
 420                                 if (hits[i].childNodes[j].nodeName
 421                                     == 'location') {
 422                                     var locNode = hits[i].childNodes[j];
 423                                     var id = locNode.getAttribute('id');
 424                                     show.hits[i]['location'][id] = {
 425                                         "id": locNode.getAttribute("id"),
 426                                         "name": locNode.getAttribute("name")
 427                                     };
 428                                 }
 429                                 else {
 430                                     var nodeName =
 431                                         hits[i].childNodes[j].nodeName;
 432                                     var nodeText = 'ERROR'
 433                                     if ( hits[i].childNodes[j].firstChild )
 434                                         nodeText =
 435                                             hits[i].childNodes[j]
 436                                                 .firstChild.nodeValue;
 437                                     show.hits[i][nodeName] = nodeText;
 438                                 }
 439                             }
 440                         }
 441                     }
 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
 453                     context.showCallback(show);
 454                 }
 455                 else
 456                     context.throwError('Show failed. Malformed WS resonse.',
 457                                         114);
 458             }
 459         );
 460     },
 461     record: function(id, offset, params)
 462     {
 463         // we may call record with no previous search if in proxy mode
 464         if( !this.searchStatusOK && this.useSessions)
 465            throw new Error(
 466             'Pz2.js: record command has to be preceded with a search command.'
 467             );
 468         if ( params == undefined )
 469             params = {};
 470
 471         if ( params.callback != undefined ) {
 472             callback = params.callback;
 473         } else {
 474             callback = this.recordCallback;
 475         }
 476
 477         // what is that?
 478         if ( params['handle'] == undefined )
 479             handle = {};
 480         else
 481             handle = params['handle'];
 482
 483         if( id !== undefined )
 484             this.currRecID = id;
 485
 486         var context = this;
 487         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 488
 489         var recordParams = { "command": "record",
 490                             "session": this.sessionID,
 491                             "id": this.currRecID };
 492
 493         if (offset !== undefined) {
 494             recordParams["offset"] = offset;
 495         }
 496
 497         if (params.syntax != undefined) {
 498             recordParams['syntax'] = params.syntax;
 499         }
 500
 501         this.currRecOffset = offset;
 502
 503         request.get(
 504             recordParams,
 505             function(data) {
 506                 var recordNode;
 507                 var record = new Array();
 508                 record['xmlDoc'] = data;
 509                 if (context.currRecOffset !== undefined) {
 510                     record['offset'] = context.currRecOffset;
 511                     callback(record, handle);
 512                 } else if ( recordNode =
 513                     data.getElementsByTagName("record")[0] ) {
 514                     // if stylesheet was fetched do not parse the response
 515                     if ( context.xslDoc ) {
 516                         record['recid'] =
 517                             recordNode.getElementsByTagName("recid")[0]
 518                                 .firstChild.nodeValue;
 519                         record['xslDoc'] =
 520                             context.xslDoc;
 521                     } else {
 522                         for ( i = 0; i < recordNode.childNodes.length; i++) {
 523                             if ( recordNode.childNodes[i].nodeType
 524                                 == Node.ELEMENT_NODE
 525                                 && recordNode.childNodes[i].nodeName
 526                                 != 'location' ) {
 527                                 var nodeName =
 528                                     recordNode.childNodes[i].nodeName;
 529                                 var nodeText =
 530                                     recordNode.childNodes[i]
 531                                         .firstChild.nodeValue;
 532                                 record[nodeName] = nodeText;
 533                             }
 534                         }
 535                         // the location might be empty!!
 536                         var locationNodes =
 537                             recordNode.getElementsByTagName("location");
 538                         record["location"] = new Array();
 539                         for ( i = 0; i < locationNodes.length; i++ ) {
 540                             record["location"][i] = {
 541                                 "id": locationNodes[i].getAttribute("id"),
 542                                 "name": locationNodes[i].getAttribute("name")
 543                             };
 544
 545                             for ( j = 0; j < locationNodes[i].childNodes.length; j++) {
 546                                 if ( locationNodes[i].childNodes[j].nodeType
 547                                     == Node.ELEMENT_NODE ) {
 548                                     var nodeName =
 549                                         locationNodes[i].childNodes[j].nodeName;
 550                                     var nodeText = '';
 551                                     if (locationNodes[i].childNodes[j]
 552                                             .firstChild)
 553                                         nodeText =
 554                                             locationNodes[i].childNodes[j]
 555                                                 .firstChild.nodeValue;
 556                                     record["location"][i][nodeName] = nodeText;
 557                                 }
 558                             }
 559                         }
 560                     }
 561
 562                     callback(record, handle);
 563                 }
 564                 else
 565                     context.throwError('Record failed. Malformed WS resonse.',
 566                                         115);
 567             }
 568         );
 569     },
 570
 571     termlist: function()
 572     {
 573         if( !this.searchStatusOK && this.useSessions )
 574             throw new Error('Pz2.js: termlist command has to be preceded with a search command.');
 575
 576         // if called explicitly takes precedence
 577         clearTimeout(this.termTimer);
 578
 579         var context = this;
 580         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
 581         request.get(
 582             {
 583                 "command": "termlist",
 584                 "session": this.sessionID,
 585                 "name": this.termKeys
 586             },
 587             function(data) {
 588                 if ( data.getElementsByTagName("termlist") ) {
 589                     var activeClients =
 590                         Number( data.getElementsByTagName("activeclients")[0]
 591                                     .childNodes[0].nodeValue );
 592                     context.activeClients = activeClients;
 593                     var termList = { "activeclients":  activeClients };
 594                     var termLists = data.getElementsByTagName("list");
 595                     //for each termlist
 596                     for (i = 0; i < termLists.length; i++) {
 597                         var listName = termLists[i].getAttribute('name');
 598                         termList[listName] = new Array();
 599                         var terms = termLists[i].getElementsByTagName('term');
 600                         //for each term in the list
 601                         for (j = 0; j < terms.length; j++) {
 602                             var term = {
 603                                 "name":
 604                                     (terms[j].getElementsByTagName("name")[0]
 605                                         .childNodes.length
 606                                     ? terms[j].getElementsByTagName("name")[0]
 607                                         .childNodes[0].nodeValue
 608                                     : 'ERROR'),
 609                                 "freq":
 610                                     terms[j]
 611                                     .getElementsByTagName("frequency")[0]
 612                                     .childNodes[0].nodeValue || 'ERROR'
 613                             };
 614
 615                             var termIdNode =
 616                                 terms[j].getElementsByTagName("id");
 617                             if(terms[j].getElementsByTagName("id").length)
 618                                 term["id"] =
 619                                     termIdNode[0].childNodes[0].nodeValue;
 620                             termList[listName][j] = term;
 621                         }
 622                     }
 623
 624                     context.termCounter++;
 625                     var delay = context.termTime
 626                         + context.termCounter * context.dumpFactor;
 627                     if ( activeClients > 0 )
 628                         context.termTimer =
 629                             setTimeout(
 630                                 function () {
 631                                     context.termlist();
 632                                 },
 633                                 delay
 634                             );
 635
 636                    context.termlistCallback(termList);
 637                 }
 638                 else
 639                     context.throwError('Termlist failed. Malformed WS resonse.',
 640                                         116);
 641             }
 642         );
 643
 644     },
 645     bytarget: function()
 646     {
 647         if( !this.initStatusOK && this.useSessions )
 648             throw new Error('Pz2.js: bytarget command has to be preceded with a search command.');
 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.get(
 660             { "command": "bytarget", "session": this.sessionID },
 661             function(data) {
 662                 if ( data.getElementsByTagName("status")[0]
 663                         .childNodes[0].nodeValue == "OK" ) {
 664                     var targetNodes = data.getElementsByTagName("target");
 665                     var bytarget = new Array();
 666                     for ( i = 0; i < targetNodes.length; i++) {
 667                         bytarget[i] = new Array();
 668                         for( j = 0; j < targetNodes[i].childNodes.length; j++ ) {
 669                             if ( targetNodes[i].childNodes[j].nodeType
 670                                 == Node.ELEMENT_NODE ) {
 671                                 var nodeName =
 672                                     targetNodes[i].childNodes[j].nodeName;
 673                                 var nodeText =
 674                                     targetNodes[i].childNodes[j]
 675                                         .firstChild.nodeValue;
 676                                 bytarget[i][nodeName] = nodeText;
 677                             }
 678                         }
 679                     }
 680
 681                     context.bytargetCounter++;
 682                     var delay = context.bytargetTime
 683                         + context.bytargetCounter * context.dumpFactor;
 684                     if ( context.activeClients > 0 )
 685                         context.bytargetTimer =
 686                             setTimeout(
 687                                 function () {
 688                                     context.bytarget();
 689                                 },
 690                                 delay
 691                             );
 692
 693                     context.bytargetCallback(bytarget);
 694                 }
 695                 else
 696                     context.throwError('Bytarget failed. Malformed WS resonse.',
 697                                         117);
 698             }
 699         );
 700     },
 701
 702     // just for testing, probably shouldn't be here
 703     showNext: function(page)
 704     {
 705         var step = page || 1;
 706         this.show( ( step * this.currentNum ) + this.currentStart );
 707     },
 708
 709     showPrev: function(page)
 710     {
 711         if (this.currentStart == 0 )
 712             return false;
 713         var step = page || 1;
 714         var newStart = this.currentStart - (step * this.currentNum );
 715         this.show( newStart > 0 ? newStart : 0 );
 716     },
 717
 718     showPage: function(pageNum)
 719     {
 720         //var page = pageNum || 1;
 721         this.show(pageNum * this.currentNum);
 722     }
 723 };
 724
 725 /*
 726 ********************************************************************************
 727 ** AJAX HELPER CLASS ***********************************************************
 728 ********************************************************************************
 729 */
 730 var pzHttpRequest = function ( url, errorHandler ) {
 731         this.request = null;
 732         this.url = url;
 733         this.errorHandler = errorHandler || null;
 734         this.async = true;
 735
 736         if ( window.XMLHttpRequest ) {
 737             this.request = new XMLHttpRequest();
 738         } else if ( window.ActiveXObject ) {
 739             try {
 740                 this.request = new ActiveXObject( 'Msxml2.XMLHTTP' );
 741             } catch (err) {
 742                 this.request = new ActiveXObject( 'Microsoft.XMLHTTP' );
 743             }
 744         }
 745 };
 746
 747 pzHttpRequest.prototype =
 748 {
 749     get: function ( params, callback )
 750     {
 751         this._send( 'GET', params, '', callback );
 752     },
 753
 754     post: function ( params, data, callback )
 755     {
 756         this._send( 'POST', params, data, callback );
 757     },
 758
 759     load: function ()
 760     {
 761         this.async = false;
 762         this.request.open( 'GET', this.url, this.async );
 763         this.request.send('');
 764         if ( this.request.status == 200 )
 765             return this.request.responseXML;
 766     },
 767
 768     _send: function ( type, params, data, callback )
 769     {
 770         this.callback = callback;
 771         var context = this;
 772         this.async = true;
 773         this.request.open( type, this._urlAppendParams(params), this.async );
 774         this.request.onreadystatechange = function () {
 775             context._handleResponse();
 776         }
 777         this.request.send(data);
 778     },
 779
 780     _urlAppendParams: function (params)
 781     {
 782         var getUrl = this.url;
 783
 784         var sep = '?';
 785         var el = params;
 786         for (var key in el) {
 787             if (el[key] != null) {
 788                 getUrl += sep + key + '=' + encodeURIComponent(el[key]);
 789                 sep = '&';
 790             }
 791         }
 792         return getUrl;
 793     },
 794
 795     _handleResponse: function ()
 796     {
 797         if ( this.request.readyState == 4 ) {
 798             // pick up pazpr2 errors first
 799             if ( this.request.responseXML
 800                 && this.request.responseXML.documentElement.nodeName == 'error'
 801                 && this.request.responseXML.getElementsByTagName("error").length ) {
 802                 var errAddInfo = '';
 803                 if ( this.request.responseXML.getElementsByTagName("error")[0].childNodes.length )
 804                     errAddInfo = ': ' + this.request.responseXML.getElementsByTagName("error")[0].childNodes[0].nodeValue;
 805                 var errMsg = this.request.responseXML.getElementsByTagName("error")[0].getAttribute("msg");
 806                 var errCode = this.request.responseXML.getElementsByTagName("error")[0].getAttribute("code");
 807
 808                 var err = new Error(errMsg + errAddInfo);
 809                 err.code = errCode;
 810
 811                 if (this.errorHandler) {
 812                     this.errorHandler(err);
 813                 }
 814                 else {
 815                     throw err;
 816                 }
 817             } else if ( this.request.status == 200 ) {
 818                 this.callback( this.request.responseXML );
 819             } else {
 820                 var err = new Error("Pz2.js: HTTP request error (AJAX). Code: "
 821                             + this.request.status + " Info: "
 822                             + this.request.statusText );
 823                 err.code = 'HTTP';
 824
 825                 if (this.errorHandler) {
 826                     this.errorHandler(err);
 827                 }
 828                 else {
 829                     throw err;
 830                 }
 831             }
 832         }
 833     }
 834 };
 835
 836 /*
 837 *********************************************************************************
 838 ** XML HELPER CLASS ************************************************************
 839 *********************************************************************************
 840 */
 841
 842 // DOMDocument
 843
 844 if ( window.ActiveXObject) {
 845     var DOMDoc = document;
 846 } else {
 847     var DOMDoc = Document.prototype;
 848 }
 849
 850 DOMDoc.newXmlDoc = function ( root )
 851 {
 852     var doc;
 853
 854     if (document.implementation && document.implementation.createDocument) {
 855         doc = document.implementation.createDocument('', root, null);
 856     } else if ( window.ActiveXObject ) {
 857         doc = new ActiveXObject("MSXML2.DOMDocument");
 858         doc.loadXML('<' + root + '/>');
 859     } else {
 860         throw new Error ('No XML support in this browser');
 861     }
 862
 863     return doc;
 864 }
 865
 866
 867 DOMDoc.parseXmlFromString = function ( xmlString )
 868 {
 869     var doc;
 870
 871     if ( window.DOMParser ) {
 872         var parser = new DOMParser();
 873         doc = parser.parseFromString( xmlString, "text/xml");
 874     } else if ( window.ActiveXObject ) {
 875         doc = new ActiveXObject("MSXML2.DOMDocument");
 876         doc.loadXML( xmlString );
 877     } else {
 878         throw new Error ("No XML parsing support in this browser.");
 879     }
 880
 881     return doc;
 882 }
 883
 884 DOMDoc.transformToDoc = function (xmlDoc, xslDoc)
 885 {
 886     if ( window.XSLTProcessor ) {
 887         var proc = new XSLTProcessor();
 888         proc.importStylesheet( xslDoc );
 889         return proc.transformToDocument(xmlDoc);
 890     } else if ( window.ActiveXObject ) {
 891         return document.parseXmlFromString(xmlDoc.transformNode(xslDoc));
 892     } else {
 893         alert( 'Unable to perform XSLT transformation in this browser' );
 894     }
 895 }
 896
 897 // DOMElement
 898
 899 Element_removeFromDoc = function (DOM_Element)
 900 {
 901     DOM_Element.parentNode.removeChild(DOM_Element);
 902 }
 903
 904 Element_emptyChildren = function (DOM_Element)
 905 {
 906     while( DOM_Element.firstChild ) {
 907         DOM_Element.removeChild( DOM_Element.firstChild )
 908     }
 909 }
 910
 911 Element_appendTransformResult = function ( DOM_Element, xmlDoc, xslDoc )
 912 {
 913     if ( window.XSLTProcessor ) {
 914         var proc = new XSLTProcessor();
 915         proc.importStylesheet( xslDoc );
 916         var docFrag = false;
 917         docFrag = proc.transformToFragment( xmlDoc, DOM_Element.ownerDocument );
 918         DOM_Element.appendChild(docFrag);
 919     } else if ( window.ActiveXObject ) {
 920         DOM_Element.innerHTML = xmlDoc.transformNode( xslDoc );
 921     } else {
 922         alert( 'Unable to perform XSLT transformation in this browser' );
 923     }
 924 }
 925
 926 Element_appendTextNode = function (DOM_Element, tagName, textContent )
 927 {
 928     var node = DOM_Element.ownerDocument.createElement(tagName);
 929     var text = DOM_Element.ownerDocument.createTextNode(textContent);
 930
 931     DOM_Element.appendChild(node);
 932     node.appendChild(text);
 933
 934     return node;
 935 }
 936
 937 Element_setTextContent = function ( DOM_Element, textContent )
 938 {
 939     if (typeof DOM_Element.textContent !== "undefined") {
 940         DOM_Element.textContent = textContent;
 941     } else if (typeof DOM_Element.innerText !== "undefined" ) {
 942         DOM_Element.innerText = textContent;
 943     } else {
 944         throw new Error("Cannot set text content of the node, no such method.");
 945     }
 946 }
 947
 948 Element_getTextContent = function (DOM_Element)
 949 {
 950     if ( typeof DOM_Element.textContent != 'undefined' ) {
 951         return DOM_Element.textContent;
 952     } else if (typeof DOM_Element.text != 'undefined') {
 953         return DOM_Element.text;
 954     } else {
 955         throw new Error("Cannot get text content of the node, no such method.");
 956     }
 957 }
 958
 959 }