source: Dev/trunk/src/client/dojox/data/util/JsonQuery.js

define(["dojo", "dojox"], function(dojo, dojox) {

// this is a mixin to convert object attribute queries to
// JSONQuery/JSONPath syntax to be sent to the server.
return dojo.declare("dojox.data.util.JsonQuery", null, {
        useFullIdInQueries: false,
        _toJsonQuery: function(args, jsonQueryPagination){
                var first = true;
                var self = this;
                function buildQuery(path, query){
                        var isDataItem = query.__id;
                        if(isDataItem){
                                // it is a reference to a persisted object, need to make it a query by id
                                var newQuery = {};
                                newQuery[self.idAttribute] = self.useFullIdInQueries ? query.__id : query[self.idAttribute];
                                query = newQuery;
                        }
                        for(var i in query){
                                // iterate through each property, adding them to the overall query
                                var value = query[i];
                                var newPath = path + (/^[a-zA-Z_][\w_]*$/.test(i) ? '.' + i : '[' + dojo._escapeString(i) + ']');
                                if(value && typeof value == "object"){
                                        buildQuery(newPath, value);
                                }else if(value!="*"){ // full wildcards can be ommitted
                                        jsonQuery += (first ? "" : "&") + newPath +
                                                ((!isDataItem && typeof value == "string" && args.queryOptions && args.queryOptions.ignoreCase) ? "~" : "=") +
                                                 (self.simplifiedQuery ? encodeURIComponent(value) : dojo.toJson(value));
                                        first = false;
                                }
                        }
                }
                // performs conversion of Dojo Data query objects and sort arrays to JSONQuery strings
                if(args.query && typeof args.query == "object"){
                        // convert Dojo Data query objects to JSONQuery
                        var jsonQuery = "[?(";
                        buildQuery("@", args.query);
                        if(!first){
                                // use ' instead of " for quoting in JSONQuery, and end with ]
                                jsonQuery += ")]";
                        }else{
                                jsonQuery = "";
                        }
                        args.queryStr = jsonQuery.replace(/\\"|"/g,function(t){return t == '"' ? "'" : t;});
                }else if(!args.query || args.query == '*'){
                        args.query = "";
                }
                
                var sort = args.sort;
                if(sort){
                        // if we have a sort order, add that to the JSONQuery expression
                        args.queryStr = args.queryStr || (typeof args.query == 'string' ? args.query : "");
                        first = true;
                        for(i = 0; i < sort.length; i++){
                                args.queryStr += (first ? '[' : ',') + (sort[i].descending ? '\\' : '/') + "@[" + dojo._escapeString(sort[i].attribute) + "]";
                                first = false;
                        }
                        args.queryStr += ']';
                }
                // this is optional because with client side paging JSONQuery doesn't yield the total count
                if(jsonQueryPagination && (args.start || args.count)){
                        // pagination
                        args.queryStr = (args.queryStr || (typeof args.query == 'string' ? args.query : "")) +
                                '[' + (args.start || '') + ':' + (args.count ? (args.start || 0) + args.count : '') + ']';
                }
                if(typeof args.queryStr == 'string'){
                        args.queryStr = args.queryStr.replace(/\\"|"/g,function(t){return t == '"' ? "'" : t;});
                        return args.queryStr;
                }
                return args.query;
        },
        jsonQueryPagination: true,
        fetch: function(args){
                this._toJsonQuery(args, this.jsonQueryPagination);
                return this.inherited(arguments);
        },
        isUpdateable: function(){
                return true;
        },
        matchesQuery: function(item,request){
                request._jsonQuery = request._jsonQuery || dojox.json.query(this._toJsonQuery(request));
                return request._jsonQuery([item]).length;
        },
        clientSideFetch: function(/*Object*/ request,/*Array*/ baseResults){
                request._jsonQuery = request._jsonQuery || dojox.json.query(this._toJsonQuery(request));
                // we use client side paging function here instead of JSON Query because we must also determine the total count
                return this.clientSidePaging(request, request._jsonQuery(baseResults));
        },
        querySuperSet: function(argsSuper,argsSub){
                if(!argsSuper.query){
                        return argsSub.query;
                }
                return this.inherited(arguments);
        }
        
});

});