3a9980787bb5d0fe966140b243a4a5eb6768913e
[pazpar2-moved-to-github.git] / js / pz2.js
1 /*
2  * $Id$
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 supplied."); 
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                         if (data.getElementsByTagName("keepAlive").length > 0) {
205                             context.keepAlive = data.getElementsByTagName("keepAlive")[0].childNodes[0].nodeValue;
206                         }
207                         context.pingTimer =
208                             setTimeout(
209                                 function () {
210                                     context.ping();
211                                 },
212                                 context.keepAlive
213                             );
214                         if ( context.initCallback )
215                             context.initCallback();
216                     }
217                     else
218                         context.throwError('Init failed. Malformed WS resonse.',
219                                             110);
220                 }
221             );
222         // when through proxy no need to init
223         } else {
224             this.initStatusOK = true;
225         }
226     },
227     // no need to ping explicitly
228     ping: function () 
229     {
230         // pinging only makes sense when using pazpar2 directly
231         if( !this.initStatusOK || !this.useSessions )
232             throw new Error(
233             'Pz2.js: Ping not allowed (proxy mode) or session not initialized.'
234             );
235         var context = this;
236
237         clearTimeout(context.pingTimer);
238
239         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
240         request.safeGet(
241             { "command": "ping", "session": this.sessionID, "windowid" : window.name },
242             function(data) {
243                 if ( data.getElementsByTagName("status")[0]
244                         .childNodes[0].nodeValue == "OK" ) {
245                     context.pingStatusOK = true;
246                     context.pingTimer =
247                         setTimeout(
248                             function () {
249                                 context.ping();
250                             },
251                             context.keepAlive
252                         );
253                 }
254                 else
255                     context.throwError('Ping failed. Malformed WS resonse.',
256                                         111);
257             }
258         );
259     },
260     search: function (query, num, sort, filter, showfrom, addParamsArr)
261     {
262         clearTimeout(this.statTimer);
263         clearTimeout(this.showTimer);
264         clearTimeout(this.termTimer);
265         clearTimeout(this.bytargetTimer);
266         
267         this.showCounter = 0;
268         this.termCounter = 0;
269         this.bytargetCounter = 0;
270         this.statCounter = 0;
271         this.activeClients = 1;
272         
273         // no proxy mode
274         if( !this.initStatusOK )
275             throw new Error('Pz2.js: session not initialized.');
276         
277         if( query !== undefined )
278             this.currQuery = query;
279         else
280             throw new Error("Pz2.js: no query supplied to the search command.");
281         
282         if ( showfrom !== undefined )
283             var start = showfrom;
284         else
285             var start = 0;
286
287         var searchParams = { 
288           "command": "search",
289           "query": this.currQuery, 
290           "session": this.sessionID,
291           "windowid" : window.name
292         };
293         
294         if( sort !== undefined ) {
295             this.currentSort = sort;
296             searchParams["sort"] = sort;
297         }
298         if (filter !== undefined)
299                 searchParams["filter"] = filter;
300
301         // copy additional parmeters, do not overwrite
302         if (addParamsArr != undefined) {
303             for (var prop in addParamsArr) {
304                 if (!searchParams.hasOwnProperty(prop))
305                     searchParams[prop] = addParamsArr[prop];
306             }
307         }
308         
309         var context = this;
310         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
311         request.safeGet(
312             searchParams,
313             function(data) {
314                 if ( data.getElementsByTagName("status")[0]
315                         .childNodes[0].nodeValue == "OK" ) {
316                     context.searchStatusOK = true;
317                     //piggyback search
318                     context.show(start, num, sort);
319                     if (context.statCallback)
320                         context.stat();
321                     if (context.termlistCallback)
322                         context.termlist();
323                     if (context.bytargetCallback)
324                         context.bytarget();
325                 }
326                 else
327                     context.throwError('Search failed. Malformed WS resonse.',
328                                         112);
329             }
330         );
331     },
332     stat: function()
333     {
334         if( !this.initStatusOK )
335             throw new Error('Pz2.js: session not initialized.');
336         
337         // if called explicitly takes precedence
338         clearTimeout(this.statTimer);
339         
340         var context = this;
341         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
342         request.safeGet(
343             { "command": "stat", "session": this.sessionID, "windowid" : window.name },
344             function(data) {
345                 if ( data.getElementsByTagName("stat") ) {
346                     var activeClients = 
347                         Number( data.getElementsByTagName("activeclients")[0]
348                                     .childNodes[0].nodeValue );
349                     context.activeClients = activeClients;
350
351                     var stat = Element_parseChildNodes(data.documentElement);
352
353                     context.statCounter++;
354                     var delay = context.statTime 
355                         + context.statCounter * context.dumpFactor;
356                     
357                     if ( activeClients > 0 )
358                         context.statTimer = 
359                             setTimeout( 
360                                 function () {
361                                     context.stat();
362                                 },
363                                 delay
364                             );
365                     context.statCallback(stat);
366                 }
367                 else
368                     context.throwError('Stat failed. Malformed WS resonse.',
369                                         113);
370             }
371         );
372     },
373     show: function(start, num, sort, query_state)
374     {
375         if( !this.searchStatusOK && this.useSessions )
376             throw new Error(
377                 'Pz2.js: show command has to be preceded with a search command.'
378             );
379         
380         // if called explicitly takes precedence
381         clearTimeout(this.showTimer);
382         
383         if( sort !== undefined )
384             this.currentSort = sort;
385         if( start !== undefined )
386             this.currentStart = Number( start );
387         if( num !== undefined )
388             this.currentNum = Number( num );
389
390         var context = this;
391         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
392         var requestParameters = 
393           {
394               "command": "show", 
395               "session": this.sessionID, 
396               "start": this.currentStart,
397               "num": this.currentNum, 
398               "sort": this.currentSort, 
399               "block": 1,
400               "type": this.showResponseType,
401               "windowid" : window.name
402           };
403         if (query_state)
404           requestParameters["query-state"] = query_state;
405         if (this.version && this.version > 0)
406             requestParameters["version"] = this.version;
407         request.safeGet(
408           requestParameters,
409           function(data, type) {
410             var show = null;
411             var activeClients = 0;
412             if (type === "json") {
413               show = {};
414               activeClients = Number(data.activeclients[0]);
415               show.activeclients = activeClients;
416               show.merged = Number(data.merged[0]);
417               show.total = Number(data.total[0]);
418               show.start = Number(data.start[0]);
419               show.num = Number(data.num[0]);
420               show.hits = data.hit;
421             } else if (data.getElementsByTagName("status")[0]
422                   .childNodes[0].nodeValue == "OK") {
423                 // first parse the status data send along with records
424                 // this is strictly bound to the format
425                 activeClients = 
426                   Number(data.getElementsByTagName("activeclients")[0]
427                       .childNodes[0].nodeValue);
428                 show = {
429                   "activeclients": activeClients,
430                   "merged": 
431                     Number( data.getElementsByTagName("merged")[0]
432                         .childNodes[0].nodeValue ),
433                   "total": 
434                     Number( data.getElementsByTagName("total")[0]
435                         .childNodes[0].nodeValue ),
436                   "start": 
437                     Number( data.getElementsByTagName("start")[0]
438                         .childNodes[0].nodeValue ),
439                   "num": 
440                     Number( data.getElementsByTagName("num")[0]
441                         .childNodes[0].nodeValue ),
442                   "hits": []
443                 };
444                 // parse all the first-level nodes for all <hit> tags
445                 var hits = data.getElementsByTagName("hit");
446                 for (i = 0; i < hits.length; i++)
447                   show.hits[i] = Element_parseChildNodes(hits[i]);
448             } else {
449               context.throwError('Show failed. Malformed WS resonse.',
450                   114);
451             };
452             
453             var approxNode = data.getElementsByTagName("approximation");
454             if (approxNode && approxNode[0] && approxNode[0].childNodes[0] && approxNode[0].childNodes[0].nodeValue)
455                 show['approximation'] = 
456                   Number( approxNode[0].childNodes[0].nodeValue);
457               
458
459               data.getElementsByTagName("")
460             context.activeClients = activeClients; 
461             context.showCounter++;
462             var delay = context.showTime;
463             if (context.showCounter > context.showFastCount)
464               delay += context.showCounter * context.dumpFactor;
465             if ( activeClients > 0 )
466               context.showTimer = setTimeout(
467                 function () {
468                   context.show();
469                 }, 
470                 delay);
471             context.showCallback(show);
472           }
473         );
474     },
475     record: function(id, offset, syntax, handler)
476     {
477         // we may call record with no previous search if in proxy mode
478         if(!this.searchStatusOK && this.useSessions)
479            throw new Error(
480             'Pz2.js: record command has to be preceded with a search command.'
481             );
482         
483         if( id !== undefined )
484             this.currRecID = id;
485         
486         var recordParams = { 
487             "command": "record", 
488             "session": this.sessionID,
489             "id": this.currRecID,
490             "windowid" : window.name
491         };
492         
493         this.currRecOffset = null;
494         if (offset != undefined) {
495             recordParams["offset"] = offset;
496             this.currRecOffset = offset;
497         }
498
499         if (syntax != undefined)
500             recordParams['syntax'] = syntax;
501
502         //overwrite default callback id needed
503         var callback = this.recordCallback;
504         var args = undefined;
505         if (handler != undefined) {
506             callback = handler['callback'];
507             args = handler['args'];
508         }
509         
510         var context = this;
511         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
512
513         request.safeGet(
514             recordParams,
515             function(data) {
516                 var recordNode;
517                 var record;                                
518                 //raw record
519                 if (context.currRecOffset !== null) {
520                     record = new Array();
521                     record['xmlDoc'] = data;
522                     record['offset'] = context.currRecOffset;
523                     callback(record, args);
524                 //pz2 record
525                 } else if ( recordNode = 
526                     data.getElementsByTagName("record")[0] ) {
527                     // if stylesheet was fetched do not parse the response
528                     if ( context.xslDoc ) {
529                         record = new Array();
530                         record['xmlDoc'] = data;
531                         record['xslDoc'] = context.xslDoc;
532                         record['recid'] = 
533                             recordNode.getElementsByTagName("recid")[0]
534                                 .firstChild.nodeValue;
535                     //parse record
536                     } else {
537                         record = Element_parseChildNodes(recordNode);
538                     }    
539                     var activeClients = 
540                        Number( data.getElementsByTagName("activeclients")[0]
541                                 .childNodes[0].nodeValue );
542                     context.activeClients = activeClients; 
543                     context.recordCounter++;
544                     var delay = context.recordTime + context.recordCounter * context.dumpFactor;
545                     if ( activeClients > 0 )
546                         context.recordTimer = 
547                            setTimeout ( 
548                                function() {
549                                   context.record(id, offset, syntax, handler);
550                                   },
551                                   delay
552                                );                                    
553                     callback(record, args);
554                 }
555                 else
556                     context.throwError('Record failed. Malformed WS resonse.',
557                                         115);
558             }
559         );
560     },
561
562     termlist: function()
563     {
564         if( !this.searchStatusOK && this.useSessions )
565             throw new Error(
566             'Pz2.js: termlist command has to be preceded with a search command.'
567             );
568
569         // if called explicitly takes precedence
570         clearTimeout(this.termTimer);
571         
572         var context = this;
573         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
574         request.safeGet(
575             { 
576                 "command": "termlist", 
577                 "session": this.sessionID, 
578                 "name": this.termKeys,
579                 "windowid" : window.name, 
580                 "version" : this.version
581         
582             },
583             function(data) {
584                 if ( data.getElementsByTagName("termlist") ) {
585                     var activeClients = 
586                         Number( data.getElementsByTagName("activeclients")[0]
587                                     .childNodes[0].nodeValue );
588                     context.activeClients = activeClients;
589                     var termList = { "activeclients":  activeClients };
590                     var termLists = data.getElementsByTagName("list");
591                     //for each termlist
592                     for (i = 0; i < termLists.length; i++) {
593                         var listName = termLists[i].getAttribute('name');
594                         termList[listName] = new Array();
595                         var terms = termLists[i].getElementsByTagName('term');
596                         //for each term in the list
597                         for (j = 0; j < terms.length; j++) { 
598                             var term = {
599                                 "name": 
600                                     (terms[j].getElementsByTagName("name")[0]
601                                         .childNodes.length 
602                                     ? terms[j].getElementsByTagName("name")[0]
603                                         .childNodes[0].nodeValue
604                                     : 'ERROR'),
605                                 "freq": 
606                                     terms[j]
607                                     .getElementsByTagName("frequency")[0]
608                                     .childNodes[0].nodeValue || 'ERROR'
609                             };
610
611                             // Only for xtargets: id, records, filtered
612                             var termIdNode = 
613                                 terms[j].getElementsByTagName("id");
614                             if(terms[j].getElementsByTagName("id").length)
615                                 term["id"] = 
616                                     termIdNode[0].childNodes[0].nodeValue;
617                             termList[listName][j] = term;
618
619                             var recordsNode  = terms[j].getElementsByTagName("records");
620                             if (recordsNode && recordsNode.length)
621                                 term["records"] = recordsNode[0].childNodes[0].nodeValue;
622                               
623                             var filteredNode  = terms[j].getElementsByTagName("filtered");
624                             if (filteredNode && filteredNode.length)
625                                 term["filtered"] = filteredNode[0].childNodes[0].nodeValue;
626                               
627                         }
628                     }
629
630                     context.termCounter++;
631                     var delay = context.termTime 
632                         + context.termCounter * context.dumpFactor;
633                     if ( activeClients > 0 )
634                         context.termTimer = 
635                             setTimeout(
636                                 function () {
637                                     context.termlist();
638                                 }, 
639                                 delay
640                             );
641                    
642                    context.termlistCallback(termList);
643                 }
644                 else
645                     context.throwError('Termlist failed. Malformed WS resonse.',
646                                         116);
647             }
648         );
649
650     },
651     bytarget: function()
652     {
653         if( !this.initStatusOK && this.useSessions )
654             throw new Error(
655             'Pz2.js: bytarget command has to be preceded with a search command.'
656             );
657         
658         // no need to continue
659         if( !this.searchStatusOK )
660             return;
661
662         // if called explicitly takes precedence
663         clearTimeout(this.bytargetTimer);
664         
665         var context = this;
666         var request = new pzHttpRequest(this.pz2String, this.errorHandler);
667         request.safeGet(
668             { 
669                 "command": "bytarget", 
670                 "session": this.sessionID, 
671                 "block": 1,
672                 "windowid" : window.name,
673                 "version" : this.version
674             },
675             function(data) {
676                 if ( data.getElementsByTagName("status")[0]
677                         .childNodes[0].nodeValue == "OK" ) {
678                     var targetNodes = data.getElementsByTagName("target");
679                     var bytarget = new Array();
680                     for ( i = 0; i < targetNodes.length; i++) {
681                         bytarget[i] = new Array();
682                         for( j = 0; j < targetNodes[i].childNodes.length; j++ ) {
683                             if ( targetNodes[i].childNodes[j].nodeType 
684                                 == Node.ELEMENT_NODE ) {
685                                 var nodeName = 
686                                     targetNodes[i].childNodes[j].nodeName;
687                                 if (targetNodes[i].childNodes[j].firstChild != null) 
688                                 {
689                                     var nodeText = targetNodes[i].childNodes[j]
690                                         .firstChild.nodeValue;
691                                     bytarget[i][nodeName] = nodeText;
692                                 }
693                                 else { 
694                                     bytarget[i][nodeName] = "";  
695                                 }
696
697
698                             }
699                         }
700                         if (bytarget[i]["state"]=="Client_Disconnected") {
701                           bytarget[i]["hits"] = "Error";
702                         } else if (bytarget[i]["state"]=="Client_Error") {
703                           bytarget[i]["hits"] = "Error";                          
704                         } else if (bytarget[i]["state"]=="Client_Working") {
705                           bytarget[i]["hits"] = "...";
706                         }
707                         if (bytarget[i].diagnostic == "1") {
708                           bytarget[i].diagnostic = "Permanent system error";
709                         } else if (bytarget[i].diagnostic == "2") {
710                           bytarget[i].diagnostic = "Temporary system error";
711                         } 
712                         var targetsSuggestions = targetNodes[i].getElementsByTagName("suggestions");
713                         if (targetsSuggestions != undefined && targetsSuggestions.length>0) {
714                           var suggestions = targetsSuggestions[0];
715                           bytarget[i]["suggestions"] = Element_parseChildNodes(suggestions);
716                         }
717                     }
718                     
719                     context.bytargetCounter++;
720                     var delay = context.bytargetTime 
721                         + context.bytargetCounter * context.dumpFactor;
722                     if ( context.activeClients > 0 )
723                         context.bytargetTimer = 
724                             setTimeout(
725                                 function () {
726                                     context.bytarget();
727                                 }, 
728                                 delay
729                             );
730
731                     context.bytargetCallback(bytarget);
732                 }
733                 else
734                     context.throwError('Bytarget failed. Malformed WS resonse.',
735                                         117);
736             }
737         );
738     },
739     
740     // just for testing, probably shouldn't be here
741     showNext: function(page)
742     {
743         var step = page || 1;
744         this.show( ( step * this.currentNum ) + this.currentStart );     
745     },
746
747     showPrev: function(page)
748     {
749         if (this.currentStart == 0 )
750             return false;
751         var step = page || 1;
752         var newStart = this.currentStart - (step * this.currentNum );
753         this.show( newStart > 0 ? newStart : 0 );
754     },
755
756     showPage: function(pageNum)
757     {
758         //var page = pageNum || 1;
759         this.show(pageNum * this.currentNum);
760     }
761 };
762
763 /*
764 ********************************************************************************
765 ** AJAX HELPER CLASS ***********************************************************
766 ********************************************************************************
767 */
768 var pzHttpRequest = function ( url, errorHandler ) {
769         this.maxUrlLength = 2048;
770         this.request = null;
771         this.url = url;
772         this.errorHandler = errorHandler || null;
773         this.async = true;
774         this.requestHeaders = {};
775         
776         if ( window.XMLHttpRequest ) {
777             this.request = new XMLHttpRequest();
778         } else if ( window.ActiveXObject ) {
779             try {
780                 this.request = new ActiveXObject( 'Msxml2.XMLHTTP' );
781             } catch (err) {
782                 this.request = new ActiveXObject( 'Microsoft.XMLHTTP' );
783             }
784         }
785 };
786
787
788 pzHttpRequest.prototype = 
789 {
790     safeGet: function ( params, callback )
791     {
792         var encodedParams =  this.encodeParams(params);
793         var url = this._urlAppendParams(encodedParams);
794         if (url.length >= this.maxUrlLength) {
795             this.requestHeaders["Content-Type"]
796                 = "application/x-www-form-urlencoded";
797             this._send( 'POST', this.url, encodedParams, callback );
798         } else {
799             this._send( 'GET', url, '', callback );
800         }
801     },
802
803     get: function ( params, callback ) 
804     {
805         this._send( 'GET', this._urlAppendParams(this.encodeParams(params)), 
806             '', callback );
807     },
808
809     post: function ( params, data, callback )
810     {
811         this._send( 'POST', this._urlAppendParams(this.encodeParams(params)), 
812             data, callback );
813     },
814
815     load: function ()
816     {
817         this.async = false;
818         this.request.open( 'GET', this.url, this.async );
819         this.request.send('');
820         if ( this.request.status == 200 )
821             return this.request.responseXML;
822     },
823
824     encodeParams: function (params)
825     {
826         var sep = "";
827         var encoded = "";
828         for (var key in params) {
829             if (params[key] != null) {
830                 encoded += sep + key + '=' + encodeURIComponent(params[key]);
831                 sep = '&';
832             }
833         }
834         return encoded;
835     },
836
837     _send: function ( type, url, data, callback)
838     {
839         var context = this;
840         this.callback = callback;
841         this.async = true;
842         this.request.open( type, url, this.async );
843         for (var key in this.requestHeaders)
844             this.request.setRequestHeader(key, this.requestHeaders[key]);
845         this.request.onreadystatechange = function () {
846             context._handleResponse(url); /// url used ONLY for error reporting
847         }
848         this.request.send(data);
849     },
850
851     _urlAppendParams: function (encodedParams)
852     {
853         if (encodedParams)
854             return this.url + "?" + encodedParams;
855         else
856             return this.url;
857     },
858
859     _handleResponse: function (savedUrlForErrorReporting)
860     {
861         if ( this.request.readyState == 4 ) { 
862             // pick up appplication errors first
863             var errNode = null;
864             if (this.request.responseXML &&
865                 (errNode = this.request.responseXML.documentElement)
866                 && errNode.nodeName == 'error') {
867                 var errMsg = errNode.getAttribute("msg");
868                 var errCode = errNode.getAttribute("code");
869                 var errAddInfo = '';
870                 if (errNode.childNodes.length)
871                     errAddInfo = ': ' + errNode.childNodes[0].nodeValue;
872                            
873                 var err = new Error(errMsg + errAddInfo);
874                 err.code = errCode;
875             
876                 if (this.errorHandler) {
877                     this.errorHandler(err);
878                 }
879                 else {
880                     throw err;
881                 }
882             } else if (this.request.status == 200 && 
883                        this.request.responseXML == null) {
884               if (this.request.responseText != null) {
885                 //assume JSON
886                 
887                 var json = null; 
888                 var text = this.request.responseText;
889                 if (typeof window.JSON == "undefined") 
890                     json = eval("(" + text + ")");
891                 else { 
892                     try {
893                         json = JSON.parse(text);
894                     }
895                     catch (e) {
896                         // Safari: eval will fail as well. Considering trying JSON2 (non-native implementation) instead
897                         /* DEBUG only works in mk2-mobile
898                         if (document.getElementById("log")) 
899                             document.getElementById("log").innerHTML = "" + e + " " + length + ": " + text;
900                         */
901                         try {
902                             json = eval("(" + text + ")");
903                         }
904                         catch (e) {
905                             /* DEBUG only works in mk2-mobile
906                             if (document.getElementById("log")) 
907                                 document.getElementById("log").innerHTML = "" + e + " " + length + ": " + text;
908                             */
909                         }
910                     }
911                 } 
912                 this.callback(json, "json");
913               } else {
914                 var err = new Error("XML response is empty but no error " +
915                                     "for " + savedUrlForErrorReporting);
916                 err.code = -1;
917                 if (this.errorHandler) {
918                     this.errorHandler(err);
919                 } else {
920                     throw err;
921                 }
922               }
923             } else if (this.request.status == 200) {
924                 this.callback(this.request.responseXML);
925             } else {
926                 var err = new Error("HTTP response not OK: " 
927                             + this.request.status + " - " 
928                             + this.request.statusText );
929                 err.code = '00' + this.request.status;        
930                 if (this.errorHandler) {
931                     this.errorHandler(err);
932                 }
933                 else {
934                     throw err;
935                 }
936             }
937         }
938     }
939 };
940
941 /*
942 ********************************************************************************
943 ** XML HELPER FUNCTIONS ********************************************************
944 ********************************************************************************
945 */
946
947 // DOMDocument
948
949 if ( window.ActiveXObject) {
950     var DOMDoc = document;
951 } else {
952     var DOMDoc = Document.prototype;
953 }
954
955 DOMDoc.newXmlDoc = function ( root )
956 {
957     var doc;
958
959     if (document.implementation && document.implementation.createDocument) {
960         doc = document.implementation.createDocument('', root, null);
961     } else if ( window.ActiveXObject ) {
962         doc = new ActiveXObject("MSXML2.DOMDocument");
963         doc.loadXML('<' + root + '/>');
964     } else {
965         throw new Error ('No XML support in this browser');
966     }
967
968     return doc;
969 }
970
971    
972 DOMDoc.parseXmlFromString = function ( xmlString ) 
973 {
974     var doc;
975
976     if ( window.DOMParser ) {
977         var parser = new DOMParser();
978         doc = parser.parseFromString( xmlString, "text/xml");
979     } else if ( window.ActiveXObject ) {
980         doc = new ActiveXObject("MSXML2.DOMDocument");
981         doc.loadXML( xmlString );
982     } else {
983         throw new Error ("No XML parsing support in this browser.");
984     }
985
986     return doc;
987 }
988
989 DOMDoc.transformToDoc = function (xmlDoc, xslDoc)
990 {
991     if ( window.XSLTProcessor ) {
992         var proc = new XSLTProcessor();
993         proc.importStylesheet( xslDoc );
994         return proc.transformToDocument(xmlDoc);
995     } else if ( window.ActiveXObject ) {
996         return document.parseXmlFromString(xmlDoc.transformNode(xslDoc));
997     } else {
998         alert( 'Unable to perform XSLT transformation in this browser' );
999     }
1000 }
1001  
1002 // DOMElement
1003
1004 Element_removeFromDoc = function (DOM_Element)
1005 {
1006     DOM_Element.parentNode.removeChild(DOM_Element);
1007 }
1008
1009 Element_emptyChildren = function (DOM_Element)
1010 {
1011     while( DOM_Element.firstChild ) {
1012         DOM_Element.removeChild( DOM_Element.firstChild )
1013     }
1014 }
1015
1016 Element_appendTransformResult = function ( DOM_Element, xmlDoc, xslDoc )
1017 {
1018     if ( window.XSLTProcessor ) {
1019         var proc = new XSLTProcessor();
1020         proc.importStylesheet( xslDoc );
1021         var docFrag = false;
1022         docFrag = proc.transformToFragment( xmlDoc, DOM_Element.ownerDocument );
1023         DOM_Element.appendChild(docFrag);
1024     } else if ( window.ActiveXObject ) {
1025         DOM_Element.innerHTML = xmlDoc.transformNode( xslDoc );
1026     } else {
1027         alert( 'Unable to perform XSLT transformation in this browser' );
1028     }
1029 }
1030  
1031 Element_appendTextNode = function (DOM_Element, tagName, textContent )
1032 {
1033     var node = DOM_Element.ownerDocument.createElement(tagName);
1034     var text = DOM_Element.ownerDocument.createTextNode(textContent);
1035
1036     DOM_Element.appendChild(node);
1037     node.appendChild(text);
1038
1039     return node;
1040 }
1041
1042 Element_setTextContent = function ( DOM_Element, textContent )
1043 {
1044     if (typeof DOM_Element.textContent !== "undefined") {
1045         DOM_Element.textContent = textContent;
1046     } else if (typeof DOM_Element.innerText !== "undefined" ) {
1047         DOM_Element.innerText = textContent;
1048     } else {
1049         throw new Error("Cannot set text content of the node, no such method.");
1050     }
1051 }
1052
1053 Element_getTextContent = function (DOM_Element)
1054 {
1055     if ( typeof DOM_Element.textContent != 'undefined' ) {
1056         return DOM_Element.textContent;
1057     } else if (typeof DOM_Element.text != 'undefined') {
1058         return DOM_Element.text;
1059     } else {
1060         throw new Error("Cannot get text content of the node, no such method.");
1061     }
1062 }
1063
1064 Element_parseChildNodes = function (node)
1065 {
1066     var parsed = {};
1067     var hasChildElems = false;
1068     var textContent = '';
1069
1070     if (node.hasChildNodes()) {
1071         var children = node.childNodes;
1072         for (var i = 0; i < children.length; i++) {
1073             var child = children[i];
1074             switch (child.nodeType) {
1075               case Node.ELEMENT_NODE:
1076                 hasChildElems = true;
1077                 var nodeName = child.nodeName; 
1078                 if (!(nodeName in parsed))
1079                     parsed[nodeName] = [];
1080                 parsed[nodeName].push(Element_parseChildNodes(child));
1081                 break;
1082               case Node.TEXT_NODE:
1083                 textContent += child.nodeValue;
1084                 break;
1085               case Node.CDATA_SECTION_NODE:
1086                 textContent += child.nodeValue;
1087                 break;
1088             }
1089         }
1090     }
1091
1092     var attrs = node.attributes;
1093     for (var i = 0; i < attrs.length; i++) {
1094         hasChildElems = true;
1095         var attrName = '@' + attrs[i].nodeName;
1096         var attrValue = attrs[i].nodeValue;
1097         parsed[attrName] = attrValue;
1098     }
1099
1100     // if no nested elements/attrs set value to text
1101     if (hasChildElems)
1102       parsed['#text'] = textContent;
1103     else
1104       parsed = textContent;
1105     
1106     return parsed;
1107 }
1108
1109 /* do not remove trailing bracket */
1110 }