1 |
dpavlin |
1 |
/* |
2 |
|
|
Fast filtering function using pre-sorted list elements |
3 |
|
|
Dobrica Pavlinusic, dpavlin@rot13.org 2004-09-06 |
4 |
dpavlin |
10 |
Matko Andjelinic, matko.andjelinic@gmail.com 2004-09-09 (contributed OO implementation) |
5 |
dpavlin |
1 |
*/ |
6 |
|
|
|
7 |
dpavlin |
2 |
|
8 |
dpavlin |
10 |
function BFilter(arr) { |
9 |
|
|
this.id_cache = Array(); |
10 |
|
|
// total number of hits |
11 |
|
|
this.hits = 0; |
12 |
dpavlin |
1 |
|
13 |
dpavlin |
25 |
// this function is called for each result |
14 |
|
|
this.result = function (arr) { |
15 |
|
|
return '<li><a href="'+arr[1]+'">'+ |
16 |
|
|
(this.hits % 2 == 0 ? '<span style="background: #e0e0e0;">' : '') + |
17 |
|
|
arr[0] + |
18 |
|
|
(this.hits % 2 == 0 ? '</span>' : '') + |
19 |
|
|
'</a></li>'; |
20 |
|
|
} |
21 |
|
|
|
22 |
|
|
// this function is called when updating innerHTML with results |
23 |
|
|
this.display = function (html) { |
24 |
|
|
return '<ul>'+html+'</ul>'; |
25 |
|
|
} |
26 |
|
|
|
27 |
|
|
|
28 |
dpavlin |
10 |
if (! arr) { |
29 |
|
|
this.debug("ERROR: can't search empty array"); |
30 |
|
|
return; |
31 |
|
|
} |
32 |
dpavlin |
1 |
|
33 |
dpavlin |
10 |
this.arr = arr; |
34 |
|
|
this.debug("index has "+this.arr.length+" parts"); |
35 |
|
|
|
36 |
|
|
if (! arr.min_len) { |
37 |
|
|
this.results("ERROR: index structure problem"); |
38 |
|
|
return; |
39 |
dpavlin |
1 |
} else { |
40 |
dpavlin |
10 |
this.min_len = arr.min_len; |
41 |
|
|
} |
42 |
|
|
|
43 |
|
|
this.debug("index part has "+this.min_len+" parts"); |
44 |
|
|
|
45 |
|
|
this.show_status(); |
46 |
|
|
|
47 |
|
|
} |
48 |
|
|
|
49 |
|
|
BFilter.prototype.element_id = function (id,no_alert) { |
50 |
|
|
if (this.id_cache[id]) { |
51 |
|
|
return this.id_cache[id]; |
52 |
|
|
} else { |
53 |
dpavlin |
1 |
var el = document.getElementById(id); |
54 |
|
|
if (el) { |
55 |
dpavlin |
10 |
this.id_cache[id] = el; |
56 |
dpavlin |
1 |
return el; |
57 |
|
|
} else { |
58 |
dpavlin |
10 |
if (! no_alert) { |
59 |
|
|
alert("can't find element id: "+id); |
60 |
|
|
} else { |
61 |
|
|
// don't look it up again |
62 |
|
|
this.id_cache[id] = null; |
63 |
|
|
} |
64 |
dpavlin |
1 |
} |
65 |
|
|
} |
66 |
dpavlin |
22 |
return null; |
67 |
dpavlin |
1 |
} |
68 |
|
|
|
69 |
|
|
|
70 |
dpavlin |
10 |
BFilter.prototype.show_status = function (status) { |
71 |
dpavlin |
1 |
var html; |
72 |
dpavlin |
10 |
if (this.hits > 0) { |
73 |
|
|
html = "shown "+this.hits+" entries"; |
74 |
dpavlin |
1 |
} else { |
75 |
|
|
html = "no results"; |
76 |
|
|
} |
77 |
|
|
if (! status) { |
78 |
dpavlin |
10 |
html = "Enter "+this.min_len+" letter"+(this.min_len == 1 ? '' : 's')+" to filter entries"; |
79 |
dpavlin |
1 |
status = ""; |
80 |
|
|
} |
81 |
|
|
|
82 |
dpavlin |
10 |
var el = this.element_id("status"); |
83 |
dpavlin |
1 |
el.innerHTML = html+status+"\n"; |
84 |
|
|
} |
85 |
|
|
|
86 |
dpavlin |
10 |
BFilter.prototype.results = function (html,clean) { |
87 |
dpavlin |
1 |
|
88 |
|
|
if (! html) { html = ""; } |
89 |
|
|
|
90 |
|
|
// results_div.style.cursor = 'wait'; // 'auto' |
91 |
dpavlin |
10 |
var results_div = this.element_id("results"); |
92 |
dpavlin |
1 |
if (clean) { |
93 |
dpavlin |
25 |
results_div.innerHTML = html; |
94 |
dpavlin |
1 |
} else { |
95 |
dpavlin |
25 |
results_div.innerHTML += this.display(html); |
96 |
dpavlin |
1 |
} |
97 |
|
|
} |
98 |
|
|
|
99 |
dpavlin |
10 |
|
100 |
|
|
BFilter.prototype.debug = function (html) { |
101 |
|
|
|
102 |
|
|
//return; |
103 |
|
|
|
104 |
|
|
// check if debugging is on |
105 |
|
|
if (! html) { return 1; } |
106 |
|
|
|
107 |
|
|
var debug_div = this.element_id("debug",1); |
108 |
dpavlin |
22 |
if (! debug_div) { return null; } |
109 |
dpavlin |
10 |
|
110 |
dpavlin |
12 |
debug_div.innerHTML += html + "<br>\n"; |
111 |
dpavlin |
22 |
|
112 |
|
|
return null; |
113 |
dpavlin |
10 |
} |
114 |
|
|
|
115 |
|
|
|
116 |
dpavlin |
2 |
// modified binary search to find first element with substring |
117 |
dpavlin |
10 |
BFilter.prototype.binarySearch = function (arr, find) { |
118 |
dpavlin |
6 |
if (!arr || typeof (find) == "undefined" || !arr.length) { |
119 |
dpavlin |
2 |
return null; |
120 |
|
|
} |
121 |
|
|
var low = 0; |
122 |
|
|
var high = arr.length - 1; |
123 |
|
|
var middlearr = parseInt(arr.length / 2); |
124 |
|
|
var lastTry; |
125 |
|
|
while (low <= high) { |
126 |
|
|
var mid = (low + high) / 2; |
127 |
|
|
var aTry = (mid < 1) ? 0 : parseInt(mid); |
128 |
|
|
|
129 |
dpavlin |
25 |
var curr = arr[aTry][0].substr(0,find.length).toLowerCase(); |
130 |
dpavlin |
12 |
this.debug("low="+low+" high="+high+" lastTry="+lastTry+" "+aTry+": "+curr); |
131 |
dpavlin |
2 |
if (curr < find) { |
132 |
|
|
low = aTry + 1; |
133 |
|
|
continue; |
134 |
|
|
} |
135 |
|
|
if (curr > find) { |
136 |
|
|
high = aTry - 1; |
137 |
|
|
continue; |
138 |
|
|
} |
139 |
|
|
if (curr == find) { |
140 |
|
|
high = aTry - 1; |
141 |
|
|
lastTry = aTry; |
142 |
|
|
continue; |
143 |
|
|
} |
144 |
|
|
return aTry; |
145 |
|
|
} |
146 |
dpavlin |
12 |
this.debug("lastTry="+lastTry); |
147 |
dpavlin |
1 |
|
148 |
dpavlin |
2 |
if (typeof (lastTry) != "undefined") { |
149 |
|
|
return lastTry; |
150 |
|
|
} else { |
151 |
|
|
return null; |
152 |
|
|
} |
153 |
|
|
} |
154 |
|
|
|
155 |
dpavlin |
10 |
BFilter.prototype.filter = function (document, find) { |
156 |
dpavlin |
1 |
|
157 |
dpavlin |
10 |
this.results('',1); |
158 |
|
|
this.hits = 0; |
159 |
dpavlin |
1 |
|
160 |
dpavlin |
10 |
if (find.length < this.min_len) { |
161 |
|
|
this.show_status(); |
162 |
dpavlin |
1 |
return; |
163 |
|
|
} |
164 |
|
|
|
165 |
dpavlin |
12 |
this.debug("filter: '"+find+"'"); |
166 |
dpavlin |
1 |
|
167 |
|
|
var find_lc = find.toLowerCase(); |
168 |
|
|
|
169 |
dpavlin |
10 |
var part = find_lc.substr(0,this.min_len); |
170 |
dpavlin |
1 |
|
171 |
|
|
// no part found |
172 |
dpavlin |
10 |
if (! this.arr[part]) { |
173 |
|
|
this.show_status(" for <em>"+find+"</em><br>"); |
174 |
|
|
this.debug("no part "+part); |
175 |
dpavlin |
1 |
return; |
176 |
|
|
} |
177 |
|
|
|
178 |
|
|
// start anim icon |
179 |
|
|
//results("<img src=\"pie.gif\"> Please wait, filtering...\n",1); |
180 |
|
|
|
181 |
dpavlin |
22 |
var i; |
182 |
|
|
|
183 |
dpavlin |
1 |
// full part? (optimization) |
184 |
dpavlin |
10 |
if (find.length == this.min_len) { |
185 |
dpavlin |
1 |
var html = ''; |
186 |
dpavlin |
22 |
for (i = 0; i < this.arr[part].length; i++) { |
187 |
dpavlin |
25 |
html += this.result(this.arr[part][i]); |
188 |
dpavlin |
10 |
this.hits++; |
189 |
dpavlin |
1 |
} |
190 |
dpavlin |
10 |
this.results(html); |
191 |
dpavlin |
1 |
} else { |
192 |
|
|
|
193 |
dpavlin |
10 |
var from = this.binarySearch(this.arr[part], find_lc); |
194 |
dpavlin |
1 |
|
195 |
dpavlin |
2 |
if (from != null) { |
196 |
|
|
|
197 |
dpavlin |
12 |
this.debug("loop "+from+" ... "+this.arr[part].length); |
198 |
dpavlin |
5 |
|
199 |
dpavlin |
22 |
html = ''; |
200 |
dpavlin |
5 |
|
201 |
dpavlin |
22 |
for(i = from ; i < this.arr[part].length ; i++) { |
202 |
dpavlin |
25 |
if (this.arr[part][i][0].substring(0,find.length).toLowerCase() != find_lc) { |
203 |
dpavlin |
10 |
this.debug("loop exit at "+i); |
204 |
dpavlin |
2 |
break; |
205 |
|
|
} |
206 |
dpavlin |
25 |
html += this.result(this.arr[part][i]); |
207 |
dpavlin |
10 |
this.hits++; |
208 |
dpavlin |
1 |
} |
209 |
dpavlin |
5 |
|
210 |
dpavlin |
10 |
this.results(html); |
211 |
dpavlin |
1 |
} |
212 |
|
|
|
213 |
|
|
} |
214 |
|
|
|
215 |
dpavlin |
10 |
this.show_status(" for <em>"+find+"</em>"); |
216 |
dpavlin |
1 |
|
217 |
|
|
} |
218 |
|
|
|