Backbone insert data inside Model from another

I have a simple app in backbone where the logic isn't clear for me, It's my second app and I don't know if is good the logic and how I have construct it.
The goal is when I load a page I want to retrieve all folders and files of a specific directory and print it.
I have create an app general where I include another app called Folder.When I load the page I create the general app, search inside a folder and retireve folders and files into a json with an ajax function.
I have succesfull do that but my problem is how now populate my FolderView, FolderModel and Folder Collection?Is necessary to do that I think but I don't know how to pass this json to FolderCollection/FOlderModel.

This is my appView

define(['jquery' , 'backbone', 'views/folder', 'models/folder', 'collections/folder', 'models/app'],     function($, Backbone, FolderView, FolderModel, FolderCollection, AppModel){    var AppView = Backbone.View.extend({        model: AppModel,        el:$('#folder'),        initialize: function(){            console.log('initialize AppView');            this.retrievFolderFile('uploads');            //prendo le cartelle e le metto nel json            this.folders = new FolderCollection();            this.render();            //this.todos.bind('sync', this.render, this);            //this.todos.fetch();        },        render: function(){            var element = this.$el;            element.html('');            this.folders.each(function(model){                var folderView = new FolderView({model:model});                element.append(folderView.el);            });        },        retrievFolderFile: function(dir){            var here = this;            console.log('retrieveFolderFile');            $.ajax({                type: "POST",                dataType: "json",                data: {"dir": dir},                url: 'function/retrieve_folder.php',                success: function(data) {                    console.log(data);// ------------------ HERE I HAVE RESULT HOW TO PASS TO FOLDER VIEW/ COLLECTION?------                }            });        }    })    return AppView;});

This is my folderModel

define(['backbone'],function(Backbone){    var FolderModel = Backbone.Model.extend({        defaults:{            name:'Folder',            path:''        },        initialize:function(){            console.log('Initialized Folder model');        }    });    return FolderModel;});

This is my FolderCollection

define(['backbone', 'models/folder'], function(Backbone, FolderModel){    var folderCollection = Backbone.Collection.extend({        model: FolderModel,    });    return folderCollection;});

This is my FolderView

define(['jquery', 'underscore', 'backbone', 'text!templates/folder.html'], function($, _, Backbone, FolderTemplate){    var FolderView = Backbone.View.extend({        el:$('#folder'),        template: _.template(FolderTemplate),        initialize: function(){            console.log('FolderView initialized');            this.render();        },        render: function(){            console.log('FolderView render');            //$(this.el).html(this.template({model: this.options.model}));        }    });    return FolderView;});

To retrieve folder and files I use this file PHP that return me a valid json to backbone

<?php$dir = $_POST['dir'];$data = fillArrayWithFileNodes( new DirectoryIterator( '../'.$dir ) );function fillArrayWithFileNodes( DirectoryIterator $dir ){  $data = array();  foreach ( $dir as $node )  {    if ( $node->isDir() && !$node->isDot() )    {        //$data[$node->getFilename()] = fillArrayWithFileNodes( new DirectoryIterator( $node->getPathname() ) );        $arr_to_insert = array();        $arr_to_insert['name'] = $node->getFilename();        $arr_to_insert['type'] = 'folder';        array_push($data, $arr_to_insert);    }    else if ( $node->isFile() )    {      //$data[] = $node->getFilename();        $arr_to_insert = array();        $arr_to_insert['name'] = $node->getFilename();        $arr_to_insert['type'] = 'file';        array_push($data, $arr_to_insert);    }  }  return $data;}echo json_encode($data);?>

How to pass from appview the json that return me?Is correct to do the folderand filde search inside appview or I have to do it inside folderModel?Because after when I click on a folder I want to retrieve its file and folders again.Help me to understand the logic and how to pass it.I thought to call a function inside FolderCollection like parseFolderFile and insert it into a model but how?

Thanks