source: Dev/trunk/src/client/dojox/dtl/Context.js

define([
        "dojo/_base/lang",
        "./_base"
], function(lang,dd){
        return dd.Context = lang.extend(function(/*Object*/dict){
                // summary:
                //              Represents a runtime context used by DTL templates.
                this._this = {};
                dd._Context.call(this, dict);   // TODO: huh?
        }, dd._Context.prototype,               // TODO: huh?
        {
                getKeys: function(){
                        // summary:
                        //              Returns the set of keys exported by this context.
                        var keys = [];
                        for(var key in this){
                                if(this.hasOwnProperty(key) && key != "_this"){
                                        keys.push(key);
                                }
                        }
                        return keys;
                },
                extend: function(/*dojox/dtl/Context|Object*/ obj){
                        // summary:
                        //              Returns a clone of this context object, with the items from the passed objecct mixed in.
                        // obj:
                        //              The object to extend.
                        return  lang.delegate(this, obj);
                },
                filter: function(/*dojox/dtl/Context|Object|String...*/ filter){
                        // summary:
                        //              Returns a clone of this context, only containing the items defined in the filter.
                        var context = new dd.Context();
                        var keys = [];
                        var i, arg;
                        if(filter instanceof dd.Context){
                                keys = filter.getKeys();
                        }else if(typeof filter == "object"){
                                for(var key in filter){
                                        keys.push(key);
                                }
                        }else{
                                for(i = 0; arg = arguments[i]; i++){
                                        if(typeof arg == "string"){
                                                keys.push(arg);
                                        }
                                }
                        }

                        for(i = 0, key; key = keys[i]; i++){
                                context[key] = this[key];
                        }

                        return context;
                },
                setThis: function(/*Object*/ scope){
                        // summary:
                        //              Sets the object on which to perform operations. 
                        // scope:
                        //              the this ref.
                        this._this = scope;
                },
                getThis: function(){
                        // summary:
                        //              Gets the object on which to perform operations. 
                        return this._this;
                },
                hasKey: function(/*String*/key){
                        // summary:
                        //              Indicates whether the specified key is defined on this context.
                        // key:
                        //              The key to look up.
                        if(this._getter){
                                var got = this._getter(key);
                                if(typeof got != "undefined"){
                                        return true;
                                }
                        }

                        if(typeof this[key] != "undefined"){
                                return true;
                        }

                return false;
                }
        });
});