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dojo/store/util/SimpleQueryEngine.js
Maintainability
62.07
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113
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41.09
Estimated Errors
0.54
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define(["../../_base/array" /*=====, "../api/Store" =====*/], function(arrayUtil /*=====, Store =====*/){ // module: // dojo/store/util/SimpleQueryEngine return function(query, options){ // summary: // Simple query engine that matches using filter functions, named filter // functions or objects by name-value on a query object hash // // description: // The SimpleQueryEngine provides a way of getting a QueryResults through // the use of a simple object hash as a filter. The hash will be used to // match properties on data objects with the corresponding value given. In // other words, only exact matches will be returned. // // This function can be used as a template for more complex query engines; // for example, an engine can be created that accepts an object hash that // contains filtering functions, or a string that gets evaluated, etc. // // When creating a new dojo.store, simply set the store's queryEngine // field as a reference to this function. // // query: Object // An object hash with fields that may match fields of items in the store. // Values in the hash will be compared by normal == operator, but regular expressions // or any object that provides a test() method are also supported and can be // used to match strings by more complex expressions // (and then the regex's or object's test() method will be used to match values). // // options: dojo/store/api/Store.QueryOptions? // An object that contains optional information such as sort, start, and count. // // returns: Function // A function that caches the passed query under the field "matches". See any // of the "query" methods on dojo.stores. // // example: // Define a store with a reference to this engine, and set up a query method. // // | var myStore = function(options){ // | // ...more properties here // | this.queryEngine = SimpleQueryEngine; // | // define our query method // | this.query = function(query, options){ // | return QueryResults(this.queryEngine(query, options)(this.data)); // | }; // | }; // create our matching query function switch(typeof query){ default: throw new Error("Can not query with a " + typeof query); case "object": case "undefined": var queryObject = query; query = function(object){ for(var key in queryObject){ var required = queryObject[key]; if(required && required.test){ // an object can provide a test method, which makes it work with regex if(!required.test(object[key], object)){ return false; } }else if(required != object[key]){ return false; } } return true; }; break; case "string": // named query if(!this[query]){ throw new Error("No filter function " + query + " was found in store"); } query = this[query]; // fall through case "function": // fall through } function execute(array){ // execute the whole query, first we filter var results = arrayUtil.filter(array, query); // next we sort var sortSet = options && options.sort; if(sortSet){ results.sort(typeof sortSet == "function" ? sortSet : function(a, b){ for(var sort, i=0; sort = sortSet[i]; i++){ var aValue = a[sort.attribute]; var bValue = b[sort.attribute]; // valueOf enables proper comparison of dates aValue = aValue != null ? aValue.valueOf() : aValue; bValue = bValue != null ? bValue.valueOf() : bValue; if (aValue != bValue){ return !!sort.descending == (aValue == null || aValue > bValue) ? -1 : 1; } } return 0; }); } // now we paginate if(options && (options.start || options.count)){ var total = results.length; results = results.slice(options.start || 0, (options.start || 0) + (options.count || Infinity)); results.total = total; } return results; } execute.matches = query; return execute; }; });