140 lines
3.3 KiB
JavaScript
140 lines
3.3 KiB
JavaScript
// Copyright (c) 2012, Christopher Ramey | http://github.com/cramey/tidx/blob/master/LICENCE
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var Tidx = function()
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{
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// _index is the weighted, field-based reversed search term index
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this._index = {};
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// regex used to find terms inside a value
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this.v_rx = new RegExp('[\\w-]+', 'mg');
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// regex used to break out terms with a search
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this.s_rx = new RegExp('([\\w-]+)(:?:([\\w-]+)){0,1}', 'mg');
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// Adds data to index
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this.index = function(id, field, value)
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{
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var f;
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switch(typeof field){
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// Don't allow undefined fields
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case 'undefined': return;
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case 'string': f = field.toLowerCase(); break;
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default: f = String(field);
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}
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var v;
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switch(typeof value){
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// Don't allow undefined, null or object values
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case 'null': case 'undefined': case 'object': return;
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case 'string':
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v = value.toLowerCase();
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// Don't index empty fields
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if(v.length == 0){ return; }
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break;
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default: v = String(value);
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}
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// Add field to field list, as needed
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if(this._index[f] == undefined){ this._index[f] = {}; }
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// Iterate over discrete searchable terms
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var re;
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while((re = this.v_rx.exec(value)) !== null){
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var v = re[0].toLowerCase();
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// If the field in question doesn't have this term already,
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// add it.
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if(this._index[f][v] == undefined){ this._index[f][v] = {}; }
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// Add this id to the reverse index under specific field (f)
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// and term (v), if it already exists, increment the weight
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if(this._index[f][v][id] == undefined){
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this._index[f][v][id] = 1;
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} else {
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this._index[f][v][id]++;
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}
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}
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};
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// Conducts a global search for a string (value) globally,
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// iterating through all fields.
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this.gsearch = function(result, value)
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{
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// Refuse empty searches
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if(value.length == 0){ return []; }
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var v = value.toLowerCase();
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// Loop over every field
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for(var f in this._index){
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// Look for the specified search term
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if(this._index[f][v] != undefined){
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// If it exists, add the result to r, adding in the weight
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for(var i in this._index[f][v]){
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if(result[i] == undefined){ result[i] = 0; }
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result[i] += this._index[f][v][i];
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}
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}
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}
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};
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// Conducts a field specific search for a string (value)
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this.fsearch = function(result, field, value)
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{
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var f;
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switch(typeof field){
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// Don't allow undefined fields
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case 'undefined': return;
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case 'string': f = field.toLowerCase(); break;
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default: f = String(field);
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}
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if(value.length == 0){ return []; }
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var v = value.toLowerCase();
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if(this._index[f] == undefined){ return []; }
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if(this._index[f][v] == undefined){ return []; }
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for(var i in this._index[f][v]){
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if(result[i] == undefined){ result[i] = 0; }
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result[i] += this._index[f][v][i];
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}
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};
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// Multi-term searching function - this is what you should use to
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// search with, returns an array of found ids ordered by weight
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this.search = function(search)
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{
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var r = {};
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var re;
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while((re = this.s_rx.exec(search)) !== null){
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// Global term
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if(re[3] == undefined || re[3] == ''){ this.gsearch(r, re[1]); }
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// Field specific term
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else { this.fsearch(r, re[1], re[3]); }
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}
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return this.sortresult(r);
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};
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this.sortresult = function(o)
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{
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var t = [];
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for(var i in o){ t.push([i, o[i]]); }
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t.sort(function(a,b){ return b[1] - a[1]; });
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var r = [];
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for(var i in t){ r.push(t[i][0]); }
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return r;
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};
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};
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