| author |
Steve Losh <steve@stevelosh.com> |
| date |
Tue, 11 May 2010 20:14:52 -0400 |
| parents |
de96d803d2bb |
| children |
78f0cc982dec |
/**
* helper function to return a node containing the
* search summary for a given text. keywords is a list
* of stemmed words, hlwords is the list of normal, unstemmed
* words. the first one is used to find the occurance, the
* latter for highlighting it.
*/
jQuery.makeSearchSummary = function(text, keywords, hlwords) {
var textLower = text.toLowerCase();
var start = 0;
$.each(keywords, function() {
var i = textLower.indexOf(this.toLowerCase());
if (i > -1)
start = i;
});
start = Math.max(start - 120, 0);
var excerpt = ((start > 0) ? '...' : '') +
$.trim(text.substr(start, 240)) +
((start + 240 - text.length) ? '...' : '');
var rv = $('<div class="context"></div>').text(excerpt);
$.each(hlwords, function() {
rv = rv.highlightText(this, 'highlight');
});
return rv;
}
/**
* Porter Stemmer
*/
var PorterStemmer = function() {
var step2list = {
ational: 'ate',
tional: 'tion',
enci: 'ence',
anci: 'ance',
izer: 'ize',
bli: 'ble',
alli: 'al',
entli: 'ent',
eli: 'e',
ousli: 'ous',
ization: 'ize',
ation: 'ate',
ator: 'ate',
alism: 'al',
iveness: 'ive',
fulness: 'ful',
ousness: 'ous',
aliti: 'al',
iviti: 'ive',
biliti: 'ble',
logi: 'log'
};
var step3list = {
icate: 'ic',
ative: '',
alize: 'al',
iciti: 'ic',
ical: 'ic',
ful: '',
ness: ''
};
var c = "[^aeiou]"; // consonant
var v = "[aeiouy]"; // vowel
var C = c + "[^aeiouy]*"; // consonant sequence
var V = v + "[aeiou]*"; // vowel sequence
var mgr0 = "^(" + C + ")?" + V + C; // [C]VC... is m>0
var meq1 = "^(" + C + ")?" + V + C + "(" + V + ")?$"; // [C]VC[V] is m=1
var mgr1 = "^(" + C + ")?" + V + C + V + C; // [C]VCVC... is m>1
var s_v = "^(" + C + ")?" + v; // vowel in stem
this.stemWord = function (w) {
var stem;
var suffix;
var firstch;
var origword = w;
if (w.length < 3)
return w;
var re;
var re2;
var re3;
var re4;
firstch = w.substr(0,1);
if (firstch == "y")
w = firstch.toUpperCase() + w.substr(1);
// Step 1a
re = /^(.+?)(ss|i)es$/;
re2 = /^(.+?)([^s])s$/;
if (re.test(w))
w = w.replace(re,"$1$2");
else if (re2.test(w))
w = w.replace(re2,"$1$2");
// Step 1b
re = /^(.+?)eed$/;
re2 = /^(.+?)(ed|ing)$/;
if (re.test(w)) {
var fp = re.exec(w);
re = new RegExp(mgr0);
if (re.test(fp[1])) {
re = /.$/;
w = w.replace(re,"");
}
}
else if (re2.test(w)) {
var fp = re2.exec(w);
stem = fp[1];
re2 = new RegExp(s_v);
if (re2.test(stem)) {
w = stem;
re2 = /(at|bl|iz)$/;
re3 = new RegExp("([^aeiouylsz])\\1$");
re4 = new RegExp("^" + C + v + "[^aeiouwxy]$");
if (re2.test(w))
w = w + "e";
else if (re3.test(w)) {
re = /.$/;
w = w.replace(re,"");
}
else if (re4.test(w))
w = w + "e";
}
}
// Step 1c
re = /^(.+?)y$/;
if (re.test(w)) {
var fp = re.exec(w);
stem = fp[1];
re = new RegExp(s_v);
if (re.test(stem))
w = stem + "i";
}
// Step 2
re = /^(.+?)(ational|tional|enci|anci|izer|bli|alli|entli|eli|ousli|ization|ation|ator|alism|iveness|fulness|ousness|aliti|iviti|biliti|logi)$/;
if (re.test(w)) {
var fp = re.exec(w);
stem = fp[1];
suffix = fp[2];
re = new RegExp(mgr0);
if (re.test(stem))
w = stem + step2list[suffix];
}
// Step 3
re = /^(.+?)(icate|ative|alize|iciti|ical|ful|ness)$/;
if (re.test(w)) {
var fp = re.exec(w);
stem = fp[1];
suffix = fp[2];
re = new RegExp(mgr0);
if (re.test(stem))
w = stem + step3list[suffix];
}
// Step 4
re = /^(.+?)(al|ance|ence|er|ic|able|ible|ant|ement|ment|ent|ou|ism|ate|iti|ous|ive|ize)$/;
re2 = /^(.+?)(s|t)(ion)$/;
if (re.test(w)) {
var fp = re.exec(w);
stem = fp[1];
re = new RegExp(mgr1);
if (re.test(stem))
w = stem;
}
else if (re2.test(w)) {
var fp = re2.exec(w);
stem = fp[1] + fp[2];
re2 = new RegExp(mgr1);
if (re2.test(stem))
w = stem;
}
// Step 5
re = /^(.+?)e$/;
if (re.test(w)) {
var fp = re.exec(w);
stem = fp[1];
re = new RegExp(mgr1);
re2 = new RegExp(meq1);
re3 = new RegExp("^" + C + v + "[^aeiouwxy]$");
if (re.test(stem) || (re2.test(stem) && !(re3.test(stem))))
w = stem;
}
re = /ll$/;
re2 = new RegExp(mgr1);
if (re.test(w) && re2.test(w)) {
re = /.$/;
w = w.replace(re,"");
}
// and turn initial Y back to y
if (firstch == "y")
w = firstch.toLowerCase() + w.substr(1);
return w;
}
}
/**
* Search Module
*/
var Search = {
_index : null,
_queued_query : null,
_pulse_status : -1,
init : function() {
var params = $.getQueryParameters();
if (params.q) {
var query = params.q[0];
$('input[name="q"]')[0].value = query;
this.performSearch(query);
}
},
/**
* Sets the index
*/
setIndex : function(index) {
var q;
this._index = index;
if ((q = this._queued_query) !== null) {
this._queued_query = null;
Search.query(q);
}
},
hasIndex : function() {
return this._index !== null;
},
deferQuery : function(query) {
this._queued_query = query;
},
stopPulse : function() {
this._pulse_status = 0;
},
startPulse : function() {
if (this._pulse_status >= 0)
return;
function pulse() {
Search._pulse_status = (Search._pulse_status + 1) % 4;
var dotString = '';
for (var i = 0; i < Search._pulse_status; i++)
dotString += '.';
Search.dots.text(dotString);
if (Search._pulse_status > -1)
window.setTimeout(pulse, 500);
};
pulse();
},
/**
* perform a search for something
*/
performSearch : function(query) {
// create the required interface elements
this.out = $('#search-results');
this.title = $('<h2>' + _('Searching') + '</h2>').appendTo(this.out);
this.dots = $('<span></span>').appendTo(this.title);
this.status = $('<p style="display: none"></p>').appendTo(this.out);
this.output = $('<ul class="search"/>').appendTo(this.out);
$('#search-progress').text(_('Preparing search...'));
this.startPulse();
// index already loaded, the browser was quick!
if (this.hasIndex())
this.query(query);
else
this.deferQuery(query);
},
query : function(query) {
// stem the searchterms and add them to the
// correct list
var stemmer = new PorterStemmer();
var searchterms = [];
var excluded = [];
var hlterms = [];
var tmp = query.split(/\s+/);
var object = (tmp.length == 1) ? tmp[0].toLowerCase() : null;
for (var i = 0; i < tmp.length; i++) {
// stem the word
var word = stemmer.stemWord(tmp[i]).toLowerCase();
// select the correct list
if (word[0] == '-') {
var toAppend = excluded;
word = word.substr(1);
}
else {
var toAppend = searchterms;
hlterms.push(tmp[i].toLowerCase());
}
// only add if not already in the list
if (!$.contains(toAppend, word))
toAppend.push(word);
};
var highlightstring = '?highlight=' + $.urlencode(hlterms.join(" "));
console.debug('SEARCH: searching for:');
console.info('required: ', searchterms);
console.info('excluded: ', excluded);
// prepare search
var filenames = this._index.filenames;
var titles = this._index.titles;
var terms = this._index.terms;
var descrefs = this._index.descrefs;
var modules = this._index.modules;
var desctypes = this._index.desctypes;
var fileMap = {};
var files = null;
var objectResults = [];
var regularResults = [];
$('#search-progress').empty();
// lookup as object
if (object != null) {
for (var module in modules) {
if (module.indexOf(object) > -1) {
fn = modules[module];
descr = _('module, in ') + titles[fn];
objectResults.push([filenames[fn], module, '#module-'+module, descr]);
}
}
for (var prefix in descrefs) {
for (var name in descrefs[prefix]) {
var fullname = (prefix ? prefix + '.' : '') + name;
if (fullname.toLowerCase().indexOf(object) > -1) {
match = descrefs[prefix][name];
descr = desctypes[match[1]] + _(', in ') + titles[match[0]];
objectResults.push([filenames[match[0]], fullname, '#'+fullname, descr]);
}
}
}
}
// sort results descending
objectResults.sort(function(a, b) {
return (a[1] > b[1]) ? -1 : ((a[1] < b[1]) ? 1 : 0);
});
// perform the search on the required terms
for (var i = 0; i < searchterms.length; i++) {
var word = searchterms[i];
// no match but word was a required one
if ((files = terms[word]) == null)
break;
if (files.length == undefined) {
files = [files];
}
// create the mapping
for (var j = 0; j < files.length; j++) {
var file = files[j];
if (file in fileMap)
fileMap[file].push(word);
else
fileMap[file] = [word];
}
}
// now check if the files don't contain excluded terms
for (var file in fileMap) {
var valid = true;
// check if all requirements are matched
if (fileMap[file].length != searchterms.length)
continue;
// ensure that none of the excluded terms is in the
// search result.
for (var i = 0; i < excluded.length; i++) {
if (terms[excluded[i]] == file ||
$.contains(terms[excluded[i]] || [], file)) {
valid = false;
break;
}
}
// if we have still a valid result we can add it
// to the result list
if (valid)
regularResults.push([filenames[file], titles[file], '', null]);
}
// delete unused variables in order to not waste
// memory until list is retrieved completely
delete filenames, titles, terms;
// now sort the regular results descending by title
regularResults.sort(function(a, b) {
var left = a[1].toLowerCase();
var right = b[1].toLowerCase();
return (left > right) ? -1 : ((left < right) ? 1 : 0);
});
// combine both
var results = regularResults.concat(objectResults);
// print the results
var resultCount = results.length;
function displayNextItem() {
// results left, load the summary and display it
if (results.length) {
var item = results.pop();
var listItem = $('<li style="display:none"></li>');
listItem.append($('<a/>').attr(
'href',
item[0] + DOCUMENTATION_OPTIONS.FILE_SUFFIX +
highlightstring + item[2]).html(item[1]));
if (item[3]) {
listItem.append($('<span> (' + item[3] + ')</span>'));
Search.output.append(listItem);
listItem.slideDown(5, function() {
displayNextItem();
});
} else if (DOCUMENTATION_OPTIONS.HAS_SOURCE) {
$.get('_sources/' + item[0] + '.txt', function(data) {
listItem.append($.makeSearchSummary(data, searchterms, hlterms));
Search.output.append(listItem);
listItem.slideDown(5, function() {
displayNextItem();
});
});
} else {
// no source available, just display title
Search.output.append(listItem);
listItem.slideDown(5, function() {
displayNextItem();
});
}
}
// search finished, update title and status message
else {
Search.stopPulse();
Search.title.text(_('Search Results'));
if (!resultCount)
Search.status.text(_('Your search did not match any documents. Please make sure that all words are spelled correctly and that you\'ve selected enough categories.'));
else
Search.status.text(_('Search finished, found %s page(s) matching the search query.').replace('%s', resultCount));
Search.status.fadeIn(500);
}
}
displayNextItem();
}
}
$(document).ready(function() {
Search.init();
});