source: Dev/trunk/src/client/dojox/app/utils/model.js

define(["dojo/_base/lang", "dojo/Deferred", "dojo/promise/all", "dojo/when"], function(lang, Deferred, all, when){
        return function(/*Object*/ config, /*Object*/ parent, /*Object*/ app){
                // summary:
                //              model is called to create all of the models for the app, and all models for a view, it will
                //              create and call the appropriate model utility based upon the modelLoader set in the model in the config
                // description:
                //              Called for each view or for the app.  For each model in the config, it will  
                //              create the model utility based upon the modelLoader and call it to create and load the model. 
                // config: Object
                //              The models section of the config for this view or for the app.
                // parent: Object
                //              The parent of this view or the app itself, so that models from the parent will be 
                //              available to the view.
                // returns: loadedModels 
                //               loadedModels is an object holding all of the available loaded models for this view.
                var loadedModels = {};
                if(parent.loadedModels){
                        lang.mixin(loadedModels, parent.loadedModels);
                }
                if(config){
                        var allDeferred = [];
                        for(var item in config){
                                if(item.charAt(0) !== "_"){
                                        allDeferred.push(setupModel(config, item, app, loadedModels));
                                }
                        }
                        return (allDeferred.length == 0) ? loadedModels : all(allDeferred);
                }else{
                        return loadedModels;
                }
        };

        function setupModel(config, item, app, loadedModels){
                // Here we need to create the modelLoader and call it passing in the item and the config[item].params
                var params = config[item].params ? config[item].params : {};

                var modelLoader = config[item].modelLoader ? config[item].modelLoader : "dojox/app/utils/simpleModel";
                // modelLoader must be listed in the dependencies and has thus already been loaded so it _must_ be here
                // => no need for complex code here
                try{
                        var modelCtor = require(modelLoader);
                }catch(e){
                        throw new Error(modelLoader+" must be listed in the dependencies");
                }
                var loadModelDeferred = new Deferred();
                var createModelPromise;
                try{
                        createModelPromise = modelCtor(config, params, item);
                }catch(e){
                        throw new Error("Error creating "+modelLoader+" for model named ["+item+"]: "+e.message);
                }
                when(createModelPromise, lang.hitch(this, function(newModel){
                        loadedModels[item] = newModel;
                        app.log("in app/model, for item=[",item,"] loadedModels =", loadedModels);
                        loadModelDeferred.resolve(loadedModels);
                        return loadedModels;
                }), function(e){
                        throw new Error("Error loading model named ["+item+"]: "+e.message);
                });
                return loadModelDeferred;
        }
});