Problem with NestedList

[ChristineBauers]

Hi there,

I've tried the sencha nested list tutorial and I got the following problem:

This is the application:

new Ext.Application({
    name: "NestedListDemo",
    launch: function() {
        this.views.viewport = new this.views.Viewport();
    }
});

This is the viewport:

NestedListDemo.views.Viewport = Ext.extend(Ext.NestedList, {
    fullscreen: true,
    title: 'Products',
    store: NestedListDemo.music_store
});

This is the model:

Ext.regModel('ListItem', {
    fields: [
        {name: 'firstname', type: 'string'},
        {name: 'lastname', type: 'string'},
        {name: 'age', type: 'string'}
      
    ]
});

This is the store:

NestedListDemo.music_store = new Ext.data.TreeStore({
    model: 'ListItem',
    proxy: {
        type: 'ajax',
        url: 'tracks.json',
        reader: {
            type:'json',
            root: 'items'
        }
    }
});

And this is my json document:

{"items": 
    [{
        "firstname": "firstname1",
        "lastname": "lastname1",
        "age": "1"
    },{
        "firstname": "firstname2",
        "lastname": "lastname2",
        "age": "2"
    },{
        "firstname": "firstname3",
        "lastname": "lastname3",
        "age": "3"
    }]
}

The tutorial says, that the screen should now show a list of the elements from the json document, but I get the following exception:

OPTIONS file:///C:/Dokumente und Einstellungen/lyth/workspace/NestedList/assets/www/tracks.json?_dc=1320850691003&node=root

• [COLOR=red !important]Uncaught TypeError: Cannot read property 'length' of undefined[/COLOR]
  • [COLOR=red !important]Ext.data.TreeStore.Ext.extend.fillNode[/COLOR]sencha-touch.js:6
  • [COLOR=red !important]Ext.data.TreeStore.Ext.extend.onProxyLoad[/COLOR]sencha-touch.js:6
  • [COLOR=red !important](anonymous function)[/COLOR]sencha-touch.js:6
  • [COLOR=red !important]Ext.data.Connection.Ext.extend.onComplete[/COLOR]sencha-touch.js:6
  • [COLOR=red !important]Ext.data.Connection.Ext.extend.onStateChange[/COLOR]sencha-touch.js:6
  • [COLOR=red !important](anonymous function)[/COLOR]

Anybody got an idea what to do now?

Thanks in advance
Greetings

Christine

[mitchellsimoens]

Are you running from a webserver? It will probably throw that error if the JSON file could not be found