source: Dev/trunk/src/client/dojox/mvc/Output.js

define([
        "dojo/_base/declare",
        "dojo/_base/lang",
        "dojo/dom",
        "dijit/_WidgetBase",
        "dojo/regexp"
], function(declare, lang, dom, _WidgetBase, regexp){

        return declare("dojox.mvc.Output", _WidgetBase, {
                // summary:
                //              A simple widget that displays templated output, parts of which may
                //              be data-bound.
                //
                // description:
                //              Simple output example:
                //
                //              |  <span data-dojo-type="dojox/mvc/Output" data-dojo-props="value: at(model, 'balance')"></span>
                //
                //              Another simple output example:
                //
                //              |  <span data-dojo-type="dojox/mvc/Output" data-dojo-props="value: at(model, 'balance')">
                //              |    Your balance is: ${this.value}
                //              |  </span>
                //
                //
                //              The output widget being data-bound, if the balance changes in the
                //              model, the content within the `<span>` will be
                //              updated accordingly.

                // exprchar:  Character
                //              Character to use for a substitution expression, for a substitution string like ${this.value}
                //              If this class is declared in a template HTML and exprchar is used in in-line template of this class, something other than `$` should be specified to avoid conflict with exprchar of outer-template.
                exprchar: '$',
        
                // templateString: [private] String
                //              The template or data-bound output content.
                templateString : "",
        
                postscript: function(params, srcNodeRef){
                        // summary:
                        //              Override and save template from body.
                        this.srcNodeRef = dom.byId(srcNodeRef);
                        if(this.srcNodeRef){
                                this.templateString = this.srcNodeRef.innerHTML;
                                this.srcNodeRef.innerHTML = "";
                        }
                        this.inherited(arguments);
                },
        
                set: function(name, value){
                        // summary:
                        //              Override and refresh output on value change.
                        // name:
                        //              The property to set.
                        // value:
                        //              The value to set in the property.
                        this.inherited(arguments);
                        if(name === "value"){
                                this._output();
                        }
                },
        
                ////////////////////// PRIVATE METHODS ////////////////////////
        
                _updateBinding: function(name, old, current){
                        // summary:
                        //              Rebuild output UI if data binding changes.
                        // tags:
                        //              private
                        this.inherited(arguments);
                        this._output();
                },
        
                _output: function(){
                        // summary:
                        //              Produce the data-bound output.
                        // tags:
                        //              private
                        var outputNode = this.srcNodeRef || this.domNode;
                        outputNode.innerHTML = this.templateString ? this._exprRepl(this.templateString) : this.value;
                },
        
                _exprRepl: function(tmpl){
                        // summary:
                        //              Does substitution of ${foo+bar} type expressions in template string.
                        // tags:
                        //              private
                        var pThis = this, transform = function(value, key){
                                if(!value){return "";}
                                var exp = value.substr(2);
                                exp = exp.substr(0, exp.length - 1);
                                with(pThis){
                                        var val = eval(exp);
                                        return (val || val == 0 ? val : "");
                                }
                        };
                        transform = lang.hitch(this, transform);
                        return tmpl.replace(new RegExp(regexp.escapeString(this.exprchar)+"(\{.*?\})","g"),
                                function(match, key, format){
                                        return transform(match, key).toString();
                                });
                }
        });
});