Displaying values in an ext grid where the values correspond to strings in another table/model

I'm teaching myself ExtJS by building a really simple 'scrum' development tracking application. I'm currently displaying the "Backlog" as a grid panel that displays the properties of the card(user story).

Card.js (Card model)

Ext.define('AM.model.Card', {
    extend: 'Ext.data.Model',
    fields: [
                'id',
                'name',
                'priority_id',
                ...
            ]
});

Priority.js (Priority model)

Ext.define('AM.model.Priority', {
    extend: 'Ext.data.Model',
    fields: [
                'id',
                'name',
                'short_name'
            ]
});

So the data for the card will look something like this:

backlogcards.json (data)

{
    success: true,
    backlogcards: [
        {
            id: 1, 
            name: 'ONEs',
            priority_id: 2,
            ...
        },
        {
            id: 2, 
            name: 'TWOs',
            priority_id: 3,
            ...
        }
    ]
}
开发者_StackOverflow

And the priorities looks like this:

priorities.json (data)

{
    success: true,
    priorities: [
        {
            id              : 1, 
            name            : "High",
            short_name      : "H"
        },
        {
            id              : 2, 
            name            : "Medium",
            short_name      : "M"
        },
            {
            id              : 3, 
            name            : "Low",
            short_name      : "L"
        }
    ]
}

So ideally what I would like to do is have the grid panel display the short_name for the corresponding priority_id. When the item is clicked on to be edited inline, a combo box will be displayed that shows the name property. I'm half way there already.

BacklogList.js (view)

Ext.define('AM.view.card.BacklogList', {
    extend: 'Ext.grid.Panel',
    alias: 'widget.backlogcardlist',

    title: 'Backlog',
    store: 'BacklogCards',

    selType: 'cellmodel',
    plugins: [
        Ext.create('Ext.grid.plugin.CellEditing', {
            clicksToEdit: 1
        })
    ],

    columns: [
        { header: 'ID', dataIndex: 'id' },
        { header: 'Name', dataIndex: 'name', field: 'textfield' },
        {
            header: 'Priority',
            dataIndex: 'priority_id',
            width: 130,
            field: {
                xtype: 'combobox',
                typeAhead: true,
                store: 'Priorities',
                displayField: 'name',
                valueField: 'id',
                listClass: 'x-combo-list-small'
            }
        }
    ]

});

So I know the 'dataIndex' property is what I need to modify in order to change the display, but I'm not sure how to tie those two stores together.

As you can see above, priority is being displayed as a number instead of the short_name.

Is this a situation where I would need to use associations? (I only know OF them) Sencha Docs

Thank you!

EDIT1: Oh I realize I could 'hard code' a renderer property that does this change, but I would like to avoid that and instead use values from the priorities store.

    renderer: function(value){
        if (value==3)
        {
            return "L";
        }
        else if (value==2)
        {
            return "M";
        }
        else
        {
            return "H";
        }
    },

EDIT2 for Evan: Priorities store

Ext.define('AM.store.Priorities', {
    extend: 'Ext.data.Store',
    model: 'AM.model.Priority',
    autoLoad: true,

    proxy: {
        type: 'ajax',
        api: {
            read: 'app/data/priorities.json',
            update: 'app/data/updateUsers.json'
        },
        reader: {
            type: 'json',
            root: 'priorities',
            successProperty: 'success'
        }
    }
});

The store.each refers to this store, right? If so, how do I perform the each operation on it?

I tried changing the declaration line to:

var test = Ext.define('AM.store.Priorities', {

And then tried changing your code to test.each but was unsuccessful.

Thanks again!

You need to use a renderer, however there's nothing stopping you from looping over the values in the priorities store and checking, something like:

renderer: function(value) {
    var display = '';
    store.each(function(rec){
        if (rec.get('id') === value) {
            display = rec.get('name');
            return false;
        }
    });
    return display;
}