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+/*
+ Copyright (c) 2004-2011, The Dojo Foundation All Rights Reserved.
+ Available via Academic Free License >= 2.1 OR the modified BSD license.
+ see: http://dojotoolkit.org/license for details
+*/
+
+
+if(!dojo._hasResource["dojo.store.util.SimpleQueryEngine"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
+dojo._hasResource["dojo.store.util.SimpleQueryEngine"] = true;
+dojo.provide("dojo.store.util.SimpleQueryEngine");
+
+dojo.getObject("store.util", true, dojo);
+
+dojo.store.util.SimpleQueryEngine = 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.util.SimpleQueryEngine.__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 = dojo.store.util.SimpleQueryEngine;
+ // | // define our query method
+ // | this.query = function(query, options){
+ // | return dojo.store.util.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){
+ if(!required.test(object[key])){
+ 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 = dojo.filter(array, query);
+ // next we sort
+ if(options && options.sort){
+ results.sort(function(a, b){
+ for(var sort, i=0; sort = options.sort[i]; i++){
+ var aValue = a[sort.attribute];
+ var bValue = b[sort.attribute];
+ if (aValue != bValue) {
+ return !!sort.descending == 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;
+};
+
+}