out/js/search.js

/**
 search.js searchs an XML index to HTML files.

 A part of the jsfind project (http://projects.elucidsoft.net/jsfind)
 Copyright (C) 2003 Shawn Garbett

 This program is free software; you can redistribute it and/or
 modify it under the terms of the GNU General Public License
 as published by the Free Software Foundation; either version 2
 of the License, or (at your option) any later version.
 
 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.
 
 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 
 Contact Info:
 Shawn Garbett <Shawn@eLucidSoft.net>
 http://www.elucidsoft.net
 4037 General Bate Drive
 Nashville, TN 37204
*/

// Constants
var conversion = new String
      ("0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXY");

// State variables
var query_left = "";
var search_err = "";
var results    = null;
var index_path = "";

var watchdog_id = 0;
var watchdog_callback = null;

// Object to hold search results
function Result(title, link, freq)
{
  this.title=title;
  this.link=link;
  this.frequency=Number(freq);
}

// Function to merge (intersect) two result sets
function intersect_results(data)
{
  // If there are no stored results, then these are the results
  if(!results)
  {
    results = data;
    return;
  }

  var output=new Array();

  // There are existing results, to do an intersect...
  for(var i=0; i<results.length; i++)
  {
    for(var j=0; j<data.length; j++)
    {
      if(data[j].title == results[i].title)
      {
        results[i].frequency += data[j].frequency;
        output.push(results[i]);  
        break;
      }
    }
  }

  results = output;
}

/*
 From David Flanagan's, _Javascript:_The Definitive_Guide_, pg. 294-5,
  published by O'Reilly, 4th edition, 2002
*/

var debug_div = null;

function debug(msg)
{
//  return; // Disable debugging

  if (! debug_div) debug_div = document.getElementById('debug');

  // this will create debug div if it doesn't exist.
  if (! debug_div) {
        debug_div = document.createElement('div');
        document.body.appendChild(debug_div);
  }
  if (debug_div) {
        debug_div.appendChild(document.createTextNode(msg));
        debug_div.appendChild(document.createElement("br"));
  }
}

// Convert a number into a base 62 alphanumeric number string
function convert(num)
{
  var base = conversion.length;
  var pow = 1;
  var pos = 0;
  var out = "";  

  if(num == 0)
  {
    return "0";
  }

  while (num > 0)
  {
    pos = num % base;
    out = conversion.charAt(pos) + out;
    num = Math.floor(num/base);
    pow *= base;
  }

  return out;
}

function watchdog()
{
  debug ("TIMEOUT!");
  watchdog_callback(new Array());
}

var xmldoc;

// This function loads the XML document from the specified URL, and when
// it is fully loaded, passes that document and the url to the specified
// handler function.  This function works with any XML document
function loadXML(url, handler, data, result_handler)
{
  debug("loadXML("+url+","+data+")");

  // Timeout operation in 10 seconds
  watchdog_callback = result_handler;
  watchdog_id=setTimeout("watchdog()", 20000);

  debug("setTimeout = "+watchdog_id);

  try 
  {
    // Use the standard DOM Level 2 technique, if it is supported
    if (document.implementation && document.implementation.createDocument)
    {
     // Create a new Document object
      xmldoc = document.implementation.createDocument("", "", null);

      // Specify what should happen when it finishes loading
      xmldoc.onload = function() { handler(xmldoc, url, data, result_handler); }

      //xmldoc.onerror = docError;
      //xmldoc.addEventListener("load",docError,false);

      // And tell it what URL to load
      xmldoc.load(url);
      return true;
    }
    // Otherwise use Microsoft's proprietary API for Internet Explorer
    // Something about not following standards once again
    else if (window.ActiveXObject)
    {  
      xmldoc = new ActiveXObject("Microsoft.XMLDOM");   // Create doc.
      if (! xmldoc) xmldoc = new ActiveXObject("MSXML2.DOMDocument");   // Create doc.
      // Specify onload
      xmldoc.onreadystatechange = function()
      {              
        if (xmldoc.readyState == 4) handler(xmldoc, url, data, result_handler);
      }
      xmldoc.load(url);                                     // Start loading!
      return true;
    }
    // else fallback on usage of iframes to load xml (Opera 7.53 without Java and maybe old Mac browsers)
    else {
      debug("using iframe xml loader - experimental and slow");
      if (! window.xml_iframe) {
        debug("creating iframe");
        window.xml_iframe = document.createElement('div');
        window.xml_iframe.innerHTML = '<iframe src="'+url+'" name="xml_iframe" height="0" width="0" style="display: none;"></iframe>';
        document.body.appendChild(window.xml_iframe);
      } else {
        debug("loading xml in existing iframe");
        window.frames.xml_iframe.window.document.location.href = url;
      }

      // set timeout to re-check if iframe is loaded
      window.iframe_timeout = window.setInterval('iframe_xml_loaded();',100);

      // save some data for iframe_xml_loaded()
      window.xml_handler = handler;
      window.xml_url = url;
      window.xml_data = data;
      window.xml_result_handler = result_handler;
      return true;
    }
    clearTimeout(watchdog_id);
    debug("Browser incompatilibity: can't request XML document by one of supported methods");
    return false;
  }
  catch(ex)
  {
    clearTimeout(watchdog_id);
    debug("clearTimeout = "+watchdog_id);
    debug ("CAUGHT EXCEPTION!");
    result_handler(new Array());
    return false;
  }

  return true;
}

function iframe_xml_loaded() {
  debug("iframe_xmldoc_loaded");
  if (! window.frames['xml_iframe']) return;
  var xml = eval('window.frames.xml_iframe.window.document');
  if (xml) {
        clearTimeout(window.iframe_timeout);
        debug("calling handler with ("+window.xml_url+","+window.xml_data+",...)");
        window.xml_handler(window.frames.xml_iframe.window.document, window.xml_url, window.xml_data, window.xml_result_handler);
  } else {
        debug("can't eval iframe with xml");
  }
}

function loadData(xmldoc, url, pos, result_handler)
{
  clearTimeout(watchdog_id);
  debug("clearTimeout = "+watchdog_id);

  debug ("loadData("+url+","+pos+")");

  var data = new Array();

  // Get all entries
  var entries = xmldoc.getElementsByTagName("e");

  if(entries.length > pos)
  {
    // Get the links associated with this query
    var links = entries[pos].getElementsByTagName("l");

    // Dynamically append results to output
    for(var i=0; i<links.length; i++)
    {
      data.push(new Result(links[i].getAttribute("t"),
                           links[i].firstChild.data,
                           links[i].getAttribute("f")));
    }

    intersect_results(data); 

    if(query_left.length > 0)
    {
      doSearch(index_path, query_left, result_handler);  
    }
    else
    {
      results.sort(sortResults);
      result_handler(results);
    }
  }
  else
  {
    debug("INTERNAL ERROR, Inconsistent index");
    search_err="INTERNAL ERROR, Inconsistent index";
  }
}

function sortResults(a, b)
{
  return a.frequency - b.frequency;
}

function traverseTree(xmldoc, url, query, result_handler)
{
  clearTimeout(watchdog_id);
  debug("clearTimeout = "+watchdog_id);
 
  debug("traverseTree("+xmldoc+","+url+","+query+")");

  var keys = xmldoc.getElementsByTagName("k");
  var i;

  for(i = 0; i < keys.length; i++)
  {
    var key = keys[i].firstChild.data;
    debug("traverseTree: key="+key+" query="+query);
    if(key != '' && key != null)
    {
      // Case where current key is greater than query, descend
      if(key > query)
      {
        if(key != '' && key != null)
        {
          if(!loadXML(url.replace(".xml","/"+convert(i)+".xml"),
                      traverseTree,query,result_handler))
          {
            debug("Unable to locate key "+query);
            result_handler(new Array());
          }
          // make sure of garbage collection
          xmldoc=null;
          return;
        }
      }
      // Found it!
      else if(key==query)
      {
        if(!loadXML(url.replace(/(\w+\.xml)/, "_$1"),
                    loadData, i, result_handler))
        {
          debug("ERROR: Unable to locate data "+query);
          result_handler(new Array());
        }
        // make sure of garbage collection
        xmldoc=null;
        return;
      }
    }
  }
  // Look past the end...
  if(keys.length == 0 || !loadXML(url.replace(".xml","/"+convert(i)+".xml"),
              traverseTree,query,result_handler))
  {
    debug("Unable to locate key "+query);
    result_handler(new Array());
  }
  // make sure of garbage collection
  xmldoc=null;
  return;
}

function doSearch(index_name,query, result_func)
{
  //alert("doSearch("+index_name+","+query+")");
  var pos=query.search(/[\s\+]/);
  if (index_name) index_path = index_name+'/';

  if(pos < 0)
  {
    query_left = "";
  }
  else
  {
    query_left = query.slice(pos+1);
    query = query.slice(0,pos);
  } 

  if(!loadXML(index_path+"0.xml", traverseTree, query.toLowerCase(), result_func))
  {
    debug("ERROR: Couldn't find main index 0.xml");
    search_err = "INTERNAL ERROR: Unable to load main index 0.xml";
  }
}
1	/**
2	search.js searchs an XML index to HTML files.
3
4	A part of the jsfind project (http://projects.elucidsoft.net/jsfind)
5	Copyright (C) 2003 Shawn Garbett
6
7	This program is free software; you can redistribute it and/or
8	modify it under the terms of the GNU General Public License
9	as published by the Free Software Foundation; either version 2
10	of the License, or (at your option) any later version.
11
12	This program is distributed in the hope that it will be useful,
13	but WITHOUT ANY WARRANTY; without even the implied warranty of
14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15	GNU General Public License for more details.
16
17	You should have received a copy of the GNU General Public License
18	along with this program; if not, write to the Free Software
19	Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
20
21	Contact Info:
22	Shawn Garbett <Shawn@eLucidSoft.net>
23	http://www.elucidsoft.net
24	4037 General Bate Drive
25	Nashville, TN 37204
26	*/
27
28	// Constants
29	var conversion = new String
30	("0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXY");
31
32	// State variables
33	var query_left = "";
34	var search_err = "";
35	var results = null;
36	var index_path = "";
37
38	var watchdog_id = 0;
39	var watchdog_callback = null;
40
41	// Object to hold search results
42	function Result(title, link, freq)
43	{
44	this.title=title;
45	this.link=link;
46	this.frequency=Number(freq);
47	}
48
49	// Function to merge (intersect) two result sets
50	function intersect_results(data)
51	{
52	// If there are no stored results, then these are the results
53	if(!results)
54	{
55	results = data;
56	return;
57	}
58
59	var output=new Array();
60
61	// There are existing results, to do an intersect...
62	for(var i=0; i<results.length; i++)
63	{
64	for(var j=0; j<data.length; j++)
65	{
66	if(data[j].title == results[i].title)
67	{
68	results[i].frequency += data[j].frequency;
69	output.push(results[i]);
70	break;
71	}
72	}
73	}
74
75	results = output;
76	}
77
78	/*
79	From David Flanagan's, _Javascript:_The Definitive_Guide_, pg. 294-5,
80	published by O'Reilly, 4th edition, 2002
81	*/
82
83	var debug_div = null;
84
85	function debug(msg)
86	{
87	// return; // Disable debugging
88
89	if (! debug_div) debug_div = document.getElementById('debug');
90
91	// this will create debug div if it doesn't exist.
92	if (! debug_div) {
93	debug_div = document.createElement('div');
94	document.body.appendChild(debug_div);
95	}
96	if (debug_div) {
97	debug_div.appendChild(document.createTextNode(msg));
98	debug_div.appendChild(document.createElement("br"));
99	}
100	}
101
102	// Convert a number into a base 62 alphanumeric number string
103	function convert(num)
104	{
105	var base = conversion.length;
106	var pow = 1;
107	var pos = 0;
108	var out = "";
109
110	if(num == 0)
111	{
112	return "0";
113	}
114
115	while (num > 0)
116	{
117	pos = num % base;
118	out = conversion.charAt(pos) + out;
119	num = Math.floor(num/base);
120	pow *= base;
121	}
122
123	return out;
124	}
125
126	function watchdog()
127	{
128	debug ("TIMEOUT!");
129	watchdog_callback(new Array());
130	}
131
132	var xmldoc;
133
134	// This function loads the XML document from the specified URL, and when
135	// it is fully loaded, passes that document and the url to the specified
136	// handler function. This function works with any XML document
137	function loadXML(url, handler, data, result_handler)
138	{
139	debug("loadXML("+url+","+data+")");
140
141	// Timeout operation in 10 seconds
142	watchdog_callback = result_handler;
143	watchdog_id=setTimeout("watchdog()", 20000);
144
145	debug("setTimeout = "+watchdog_id);
146
147	try
148	{
149	// Use the standard DOM Level 2 technique, if it is supported
150	if (document.implementation && document.implementation.createDocument)
151	{
152	// Create a new Document object
153	xmldoc = document.implementation.createDocument("", "", null);
154
155	// Specify what should happen when it finishes loading
156	xmldoc.onload = function() { handler(xmldoc, url, data, result_handler); }
157
158	//xmldoc.onerror = docError;
159	//xmldoc.addEventListener("load",docError,false);
160
161	// And tell it what URL to load
162	xmldoc.load(url);
163	return true;
164	}
165	// Otherwise use Microsoft's proprietary API for Internet Explorer
166	// Something about not following standards once again
167	else if (window.ActiveXObject)
168	{
169	xmldoc = new ActiveXObject("Microsoft.XMLDOM"); // Create doc.
170	if (! xmldoc) xmldoc = new ActiveXObject("MSXML2.DOMDocument"); // Create doc.
171	// Specify onload
172	xmldoc.onreadystatechange = function()
173	{
174	if (xmldoc.readyState == 4) handler(xmldoc, url, data, result_handler);
175	}
176	xmldoc.load(url); // Start loading!
177	return true;
178	}
179	// else fallback on usage of iframes to load xml (Opera 7.53 without Java and maybe old Mac browsers)
180	else {
181	debug("using iframe xml loader - experimental and slow");
182	if (! window.xml_iframe) {
183	debug("creating iframe");
184	window.xml_iframe = document.createElement('div');
185	window.xml_iframe.innerHTML = '<iframe src="'+url+'" name="xml_iframe" height="0" width="0" style="display: none;"></iframe>';
186	document.body.appendChild(window.xml_iframe);
187	} else {
188	debug("loading xml in existing iframe");
189	window.frames.xml_iframe.window.document.location.href = url;
190	}
191
192	// set timeout to re-check if iframe is loaded
193	window.iframe_timeout = window.setInterval('iframe_xml_loaded();',100);
194
195	// save some data for iframe_xml_loaded()
196	window.xml_handler = handler;
197	window.xml_url = url;
198	window.xml_data = data;
199	window.xml_result_handler = result_handler;
200	return true;
201	}
202	clearTimeout(watchdog_id);
203	debug("Browser incompatilibity: can't request XML document by one of supported methods");
204	return false;
205	}
206	catch(ex)
207	{
208	clearTimeout(watchdog_id);
209	debug("clearTimeout = "+watchdog_id);
210	debug ("CAUGHT EXCEPTION!");
211	result_handler(new Array());
212	return false;
213	}
214
215	return true;
216	}
217
218	function iframe_xml_loaded() {
219	debug("iframe_xmldoc_loaded");
220	if (! window.frames['xml_iframe']) return;
221	var xml = eval('window.frames.xml_iframe.window.document');
222	if (xml) {
223	clearTimeout(window.iframe_timeout);
224	debug("calling handler with ("+window.xml_url+","+window.xml_data+",...)");
225	window.xml_handler(window.frames.xml_iframe.window.document, window.xml_url, window.xml_data, window.xml_result_handler);
226	} else {
227	debug("can't eval iframe with xml");
228	}
229	}
230
231	function loadData(xmldoc, url, pos, result_handler)
232	{
233	clearTimeout(watchdog_id);
234	debug("clearTimeout = "+watchdog_id);
235
236	debug ("loadData("+url+","+pos+")");
237
238	var data = new Array();
239
240	// Get all entries
241	var entries = xmldoc.getElementsByTagName("e");
242
243	if(entries.length > pos)
244	{
245	// Get the links associated with this query
246	var links = entries[pos].getElementsByTagName("l");
247
248	// Dynamically append results to output
249	for(var i=0; i<links.length; i++)
250	{
251	data.push(new Result(links[i].getAttribute("t"),
252	links[i].firstChild.data,
253	links[i].getAttribute("f")));
254	}
255
256	intersect_results(data);
257
258	if(query_left.length > 0)
259	{
260	doSearch(index_path, query_left, result_handler);
261	}
262	else
263	{
264	results.sort(sortResults);
265	result_handler(results);
266	}
267	}
268	else
269	{
270	debug("INTERNAL ERROR, Inconsistent index");
271	search_err="INTERNAL ERROR, Inconsistent index";
272	}
273	}
274
275	function sortResults(a, b)
276	{
277	return a.frequency - b.frequency;
278	}
279
280	function traverseTree(xmldoc, url, query, result_handler)
281	{
282	clearTimeout(watchdog_id);
283	debug("clearTimeout = "+watchdog_id);
284
285	debug("traverseTree("+xmldoc+","+url+","+query+")");
286
287	var keys = xmldoc.getElementsByTagName("k");
288	var i;
289
290	for(i = 0; i < keys.length; i++)
291	{
292	var key = keys[i].firstChild.data;
293	debug("traverseTree: key="+key+" query="+query);
294	if(key != '' && key != null)
295	{
296	// Case where current key is greater than query, descend
297	if(key > query)
298	{
299	if(key != '' && key != null)
300	{
301	if(!loadXML(url.replace(".xml","/"+convert(i)+".xml"),
302	traverseTree,query,result_handler))
303	{
304	debug("Unable to locate key "+query);
305	result_handler(new Array());
306	}
307	// make sure of garbage collection
308	xmldoc=null;
309	return;
310	}
311	}
312	// Found it!
313	else if(key==query)
314	{
315	if(!loadXML(url.replace(/(\w+\.xml)/, "_$1"),
316	loadData, i, result_handler))
317	{
318	debug("ERROR: Unable to locate data "+query);
319	result_handler(new Array());
320	}
321	// make sure of garbage collection
322	xmldoc=null;
323	return;
324	}
325	}
326	}
327	// Look past the end...
328	if(keys.length == 0 \|\| !loadXML(url.replace(".xml","/"+convert(i)+".xml"),
329	traverseTree,query,result_handler))
330	{
331	debug("Unable to locate key "+query);
332	result_handler(new Array());
333	}
334	// make sure of garbage collection
335	xmldoc=null;
336	return;
337	}
338
339	function doSearch(index_name,query, result_func)
340	{
341	//alert("doSearch("+index_name+","+query+")");
342	var pos=query.search(/[\s\+]/);
343	if (index_name) index_path = index_name+'/';
344
345	if(pos < 0)
346	{
347	query_left = "";
348	}
349	else
350	{
351	query_left = query.slice(pos+1);
352	query = query.slice(0,pos);
353	}
354
355	if(!loadXML(index_path+"0.xml", traverseTree, query.toLowerCase(), result_func))
356	{
357	debug("ERROR: Couldn't find main index 0.xml");
358	search_err = "INTERNAL ERROR: Unable to load main index 0.xml";
359	}
360	}