Question

I’m testing out extjs 4 and I have stumbled upon something, I can’t seem to figure out.

I have simple object association: Snapshot – hasMany -> Model

Now, I am trying to use XTemplate to show this association in View component, so I have my XTemplate looking like this:

Ext.create('Ext.XTemplate',
'<tpl for=".">',
'<div class="snapshot" id="{id}">',
'<h1>{snapshot}</h1>',
'<p><span class="label">Created: </span>{dateString}</p>',
'<p><span class="label">Models</span></p>',
'<tpl for="models">',
'<p>{name}  - {description}</p>',
'</tpl>',
'</div>',
'</tpl>',
'<div class="x-clear bottompad"></div>'
);

And my JSON response looks like this (showing just ‘snapshot’ node):

    {
        "id": 1,
        "snapshot": "Snapshot 1",
        "created": 1305806847000,
        "models": [
            {
                "id": 1,
                "name": "ABC",
                "description": "A B C"
            }, {

                "id": 111,
                "name": "ABCDD",
                "description": "A B C XCXC"
            }
        ]
    }

As extjs 4 introduces concept of Model I have created models for Snapshot and Model and created association according to API docs.

Snapshot model:

Ext.define('Snapshot', {
    extend: 'Ext.data.Model',
    fields: [
        {name: 'id', type: 'int'},
        'snapshot',
        {name: 'created',type: 'date', dateFormat: 'time' }

    ],
    associations:[
      {type: 'hasMany', model: 'Model', name: 'models'}  
    ],
    idProperty: 'id'
});

Model model ;P

Ext.define('Model', {
    extend: 'Ext.data.Model',
    belongsTo: 'Snapshot',
    fields: [
        { name: 'id',  type: 'int' },
        { name: 'snapshot_id', type: 'int' },            
        'name',
        'description'
    ],
    idProperty: 'id'
});

And this is where my problem lies – When I use this setup, none of my models is displayed when XTemplate is being executed, however if I remove associations from Snapshot model and just add another field called ‘models’ it works OK.

What is the best practise to display list of models correctly while using associations?
Would I have to use nested templates and custom functions to do this?

Answer 1

Good Question (+1)

It seems using the associations directly in the XTemplate is not possible (today) because XTemplate expects array of objects. (When you have associations, this is no longer true)

You have three options –

1. Get rid of associations like you
   mentioned. (does not ‘sound’ good
   but will work)
2. If you have a data view using the template, override Ext.view.AbstractView.prepareData and create array of objects from your models
3. Before you call apply, iterate over the snapshotStore.getRange() and (re)generate objects with “models” attribute and pass this array to .apply