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

  var debug_div = element_id('debug');

  if (debug_div) debug_div.innerHTML += msg+"<br/>\n";
}

// 

// 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());
}

// 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 
  {
    var xmldoc;
    // 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	function debug(msg)
83	{
84	// return; // Disable debugging
85
86	var debug_div = element_id('debug');
87
88	if (debug_div) debug_div.innerHTML += msg+"<br/>\n";
89	}
90
91	//
92
93	// Convert a number into a base 62 alphanumeric number string
94	function convert(num)
95	{
96	var base = conversion.length;
97	var pow = 1;
98	var pos = 0;
99	var out = "";
100
101	if(num == 0)
102	{
103	return "0";
104	}
105
106	while (num > 0)
107	{
108	pos = num % base;
109	out = conversion.charAt(pos) + out;
110	num = Math.floor(num/base);
111	pow *= base;
112	}
113
114	return out;
115	}
116
117	function watchdog()
118	{
119	debug ("TIMEOUT!");
120	watchdog_callback(new Array());
121	}
122
123	// This function loads the XML document from the specified URL, and when
124	// it is fully loaded, passes that document and the url to the specified
125	// handler function. This function works with any XML document
126	function loadXML(url, handler, data, result_handler)
127	{
128	debug("loadXML("+url+","+data+")");
129
130	// Timeout operation in 10 seconds
131	watchdog_callback = result_handler;
132	watchdog_id=setTimeout("watchdog()", 20000);
133
134	debug("setTimeout = "+watchdog_id);
135
136	try
137	{
138	var xmldoc;
139	// Use the standard DOM Level 2 technique, if it is supported
140	if (document.implementation && document.implementation.createDocument)
141	{
142	// Create a new Document object
143	xmldoc = document.implementation.createDocument("", "", null);
144
145	// Specify what should happen when it finishes loading
146	xmldoc.onload = function() { handler(xmldoc, url, data, result_handler); }
147
148	//xmldoc.onerror = docError;
149	//xmldoc.addEventListener("load",docError,false);
150
151	// And tell it what URL to load
152	xmldoc.load(url);
153	}
154	// Otherwise use Microsoft's proprietary API for Internet Explorer
155	// Something about not following standards once again
156	else if (window.ActiveXObject)
157	{
158	xmldoc = new ActiveXObject("Microsoft.XMLDOM"); // Create doc.
159	if (! xmldoc) xmldoc = new ActiveXObject("MSXML2.DOMDocument"); // Create doc.
160	// Specify onload
161	xmldoc.onreadystatechange = function()
162	{
163	if (xmldoc.readyState == 4) handler(xmldoc, url, data, result_handler);
164	}
165	xmldoc.load(url); // Start loading!
166	}
167	}
168	catch(ex)
169	{
170	clearTimeout(watchdog_id);
171	debug("clearTimeout = "+watchdog_id);
172	debug ("CAUGHT EXCEPTION!");
173	result_handler(new Array());
174	return false;
175	}
176
177	return true;
178	}
179
180	function loadData(xmldoc, url, pos, result_handler)
181	{
182	clearTimeout(watchdog_id);
183	debug("clearTimeout = "+watchdog_id);
184
185	debug ("loadData("+url+","+pos+")");
186
187	var data = new Array();
188
189	// Get all entries
190	var entries = xmldoc.getElementsByTagName("e");
191
192	if(entries.length > pos)
193	{
194	// Get the links associated with this query
195	var links = entries[pos].getElementsByTagName("l");
196
197	// Dynamically append results to output
198	for(var i=0; i<links.length; i++)
199	{
200	data.push(new Result(links[i].getAttribute("t"),
201	links[i].firstChild.data,
202	links[i].getAttribute("f")));
203	}
204
205	intersect_results(data);
206
207	if(query_left.length > 0)
208	{
209	doSearch(index_path, query_left, result_handler);
210	}
211	else
212	{
213	results.sort(sortResults);
214	result_handler(results);
215	}
216	}
217	else
218	{
219	debug("INTERNAL ERROR, Inconsistent index");
220	search_err="INTERNAL ERROR, Inconsistent index";
221	}
222	}
223
224	function sortResults(a, b)
225	{
226	return a.frequency - b.frequency;
227	}
228
229	function traverseTree(xmldoc, url, query, result_handler)
230	{
231	clearTimeout(watchdog_id);
232	debug("clearTimeout = "+watchdog_id);
233
234	debug("traverseTree("+xmldoc+","+url+","+query+")");
235
236	var keys = xmldoc.getElementsByTagName("k");
237	var i;
238
239	for(i = 0; i < keys.length; i++)
240	{
241	var key = keys[i].firstChild.data;
242	debug("traverseTree: key="+key+" query="+query);
243	if(key != '' && key != null)
244	{
245	// Case where current key is greater than query, descend
246	if(key > query)
247	{
248	if(key != '' && key != null)
249	{
250	if(!loadXML(url.replace(".xml","/"+convert(i)+".xml"),
251	traverseTree,query,result_handler))
252	{
253	debug("Unable to locate key "+query);
254	result_handler(new Array());
255	}
256	// make sure of garbage collection
257	xmldoc=null;
258	return;
259	}
260	}
261	// Found it!
262	else if(key==query)
263	{
264	if(!loadXML(url.replace(/(\w+\.xml)/, "_$1"),
265	loadData, i, result_handler))
266	{
267	debug("ERROR: Unable to locate data "+query);
268	result_handler(new Array());
269	}
270	// make sure of garbage collection
271	xmldoc=null;
272	return;
273	}
274	}
275	}
276	// Look past the end...
277	if(keys.length == 0 \|\| !loadXML(url.replace(".xml","/"+convert(i)+".xml"),
278	traverseTree,query,result_handler))
279	{
280	debug("Unable to locate key "+query);
281	result_handler(new Array());
282	}
283	// make sure of garbage collection
284	xmldoc=null;
285	return;
286	}
287
288	function doSearch(index_name,query, result_func)
289	{
290	//alert("doSearch("+index_name+","+query+")");
291	var pos=query.search(/[\s\+]/);
292	if (index_name) index_path = index_name+'/';
293
294	if(pos < 0)
295	{
296	query_left = "";
297	}
298	else
299	{
300	query_left = query.slice(pos+1);
301	query = query.slice(0,pos);
302	}
303
304	if(!loadXML(index_path+"0.xml", traverseTree, query.toLowerCase(), result_func))
305	{
306	debug("ERROR: Couldn't find main index 0.xml");
307	search_err = "INTERNAL ERROR: Unable to load main index 0.xml";
308	}
309	}