html/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');

  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);
    }
    // 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!
    }
  }
  catch(ex)
  {
    clearTimeout(watchdog_id);
    debug("clearTimeout = "+watchdog_id);
    debug ("CAUGHT EXCEPTION!");
    result_handler(new Array());
    return false;
  }

  return true;
}

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	if (debug_div) {
92	debug_div.appendChild(document.createTextNode(msg));
93	debug_div.appendChild(document.createElement("br"));
94	}
95	}
96
97	//
98
99	// Convert a number into a base 62 alphanumeric number string
100	function convert(num)
101	{
102	var base = conversion.length;
103	var pow = 1;
104	var pos = 0;
105	var out = "";
106
107	if(num == 0)
108	{
109	return "0";
110	}
111
112	while (num > 0)
113	{
114	pos = num % base;
115	out = conversion.charAt(pos) + out;
116	num = Math.floor(num/base);
117	pow *= base;
118	}
119
120	return out;
121	}
122
123	function watchdog()
124	{
125	debug ("TIMEOUT!");
126	watchdog_callback(new Array());
127	}
128
129	var xmldoc;
130
131	// This function loads the XML document from the specified URL, and when
132	// it is fully loaded, passes that document and the url to the specified
133	// handler function. This function works with any XML document
134	function loadXML(url, handler, data, result_handler)
135	{
136	debug("loadXML("+url+","+data+")");
137
138	// Timeout operation in 10 seconds
139	watchdog_callback = result_handler;
140	watchdog_id=setTimeout("watchdog()", 20000);
141
142	debug("setTimeout = "+watchdog_id);
143
144	try
145	{
146	// Use the standard DOM Level 2 technique, if it is supported
147	if (document.implementation && document.implementation.createDocument)
148	{
149	// Create a new Document object
150	xmldoc = document.implementation.createDocument("", "", null);
151
152	// Specify what should happen when it finishes loading
153	xmldoc.onload = function() { handler(xmldoc, url, data, result_handler); }
154
155	//xmldoc.onerror = docError;
156	//xmldoc.addEventListener("load",docError,false);
157
158	// And tell it what URL to load
159	xmldoc.load(url);
160	}
161	// Otherwise use Microsoft's proprietary API for Internet Explorer
162	// Something about not following standards once again
163	else if (window.ActiveXObject)
164	{
165	xmldoc = new ActiveXObject("Microsoft.XMLDOM"); // Create doc.
166	if (! xmldoc) xmldoc = new ActiveXObject("MSXML2.DOMDocument"); // Create doc.
167	// Specify onload
168	xmldoc.onreadystatechange = function()
169	{
170	if (xmldoc.readyState == 4) handler(xmldoc, url, data, result_handler);
171	}
172	xmldoc.load(url); // Start loading!
173	}
174	}
175	catch(ex)
176	{
177	clearTimeout(watchdog_id);
178	debug("clearTimeout = "+watchdog_id);
179	debug ("CAUGHT EXCEPTION!");
180	result_handler(new Array());
181	return false;
182	}
183
184	return true;
185	}
186
187	function loadData(xmldoc, url, pos, result_handler)
188	{
189	clearTimeout(watchdog_id);
190	debug("clearTimeout = "+watchdog_id);
191
192	debug ("loadData("+url+","+pos+")");
193
194	var data = new Array();
195
196	// Get all entries
197	var entries = xmldoc.getElementsByTagName("e");
198
199	if(entries.length > pos)
200	{
201	// Get the links associated with this query
202	var links = entries[pos].getElementsByTagName("l");
203
204	// Dynamically append results to output
205	for(var i=0; i<links.length; i++)
206	{
207	data.push(new Result(links[i].getAttribute("t"),
208	links[i].firstChild.data,
209	links[i].getAttribute("f")));
210	}
211
212	intersect_results(data);
213
214	if(query_left.length > 0)
215	{
216	doSearch(index_path, query_left, result_handler);
217	}
218	else
219	{
220	results.sort(sortResults);
221	result_handler(results);
222	}
223	}
224	else
225	{
226	debug("INTERNAL ERROR, Inconsistent index");
227	search_err="INTERNAL ERROR, Inconsistent index";
228	}
229	}
230
231	function sortResults(a, b)
232	{
233	return a.frequency - b.frequency;
234	}
235
236	function traverseTree(xmldoc, url, query, result_handler)
237	{
238	clearTimeout(watchdog_id);
239	debug("clearTimeout = "+watchdog_id);
240
241	debug("traverseTree("+xmldoc+","+url+","+query+")");
242
243	var keys = xmldoc.getElementsByTagName("k");
244	var i;
245
246	for(i = 0; i < keys.length; i++)
247	{
248	var key = keys[i].firstChild.data;
249	debug("traverseTree: key="+key+" query="+query);
250	if(key != '' && key != null)
251	{
252	// Case where current key is greater than query, descend
253	if(key > query)
254	{
255	if(key != '' && key != null)
256	{
257	if(!loadXML(url.replace(".xml","/"+convert(i)+".xml"),
258	traverseTree,query,result_handler))
259	{
260	debug("Unable to locate key "+query);
261	result_handler(new Array());
262	}
263	// make sure of garbage collection
264	xmldoc=null;
265	return;
266	}
267	}
268	// Found it!
269	else if(key==query)
270	{
271	if(!loadXML(url.replace(/(\w+\.xml)/, "_$1"),
272	loadData, i, result_handler))
273	{
274	debug("ERROR: Unable to locate data "+query);
275	result_handler(new Array());
276	}
277	// make sure of garbage collection
278	xmldoc=null;
279	return;
280	}
281	}
282	}
283	// Look past the end...
284	if(keys.length == 0 \|\| !loadXML(url.replace(".xml","/"+convert(i)+".xml"),
285	traverseTree,query,result_handler))
286	{
287	debug("Unable to locate key "+query);
288	result_handler(new Array());
289	}
290	// make sure of garbage collection
291	xmldoc=null;
292	return;
293	}
294
295	function doSearch(index_name,query, result_func)
296	{
297	//alert("doSearch("+index_name+","+query+")");
298	var pos=query.search(/[\s\+]/);
299	if (index_name) index_path = index_name+'/';
300
301	if(pos < 0)
302	{
303	query_left = "";
304	}
305	else
306	{
307	query_left = query.slice(pos+1);
308	query = query.slice(0,pos);
309	}
310
311	if(!loadXML(index_path+"0.xml", traverseTree, query.toLowerCase(), result_func))
312	{
313	debug("ERROR: Couldn't find main index 0.xml");
314	search_err = "INTERNAL ERROR: Unable to load main index 0.xml";
315	}
316	}