How to get access to the data in other Tabs

[denisputnam]

I have the following code. I want to add a calculated column in the 'What' tab by accessing the data in the 'SpotPrices' tab. Can someone tell me how to do that? I think I have to use a renderer in the 'What' tab, but the trick is how to get a hold of the data in the 'SpotPrices' tab.

Ext.define('MyApp.view.MyStuffTabPanel', {
    extend: 'Ext.tab.Panel',


    height: 503,
    resizable: true,


    initComponent: function() {
        var me = this;


        Ext.applyIf(me, {
            items: [
                {
                    xtype: 'panel',
                    height: 237,
                    resizable: true,
                    layout: {
                        type: 'fit'
                    },
                    title: 'What',
                    items: [
                        {
                            xtype: 'gridpanel',
                            height: 503,
                            autoScroll: true,
                            resizable: true,
                            title: 'WhatGridPanel',
                            store: 'MyWhatStore',
                            viewConfig: {
                                height: 503
                            },
                            columns: [
                                {
                                    xtype: 'gridcolumn',
                                    dataIndex: 'what',
                                    text: 'What'
                                },
                                {
                                    xtype: 'numbercolumn',
                                    dataIndex: 'amount',
                                    text: 'Amount'
                                },
                                {
                                    xtype: 'gridcolumn',
                                    dataIndex: 'unit',
                                    text: 'Units'
                                }
                            ]
                        }
                    ]
                },
                {
                    xtype: 'panel',
                    height: 503,
                    resizable: true,
                    layout: {
                        type: 'fit'
                    },
                    title: 'SpotPrices',
                    items: [
                        {
                            xtype: 'gridpanel',
                            height: 503,
                            autoScroll: true,
                            resizable: false,
                            title: 'SpotPricesGridPanel',
                            forceFit: true,
                            store: 'MySpotPricesStore',
                            viewConfig: {
                                height: 503,
                                autoScroll: true,
                                resizable: false
                            },
                            columns: [
                                {
                                    xtype: 'gridcolumn',
                                    maxWidth: 50,
                                    width: 50,
                                    defaultWidth: 50,
                                    dataIndex: 'symbol',
                                    text: 'Symbol'
                                },
                                {
                                    xtype: 'gridcolumn',
                                    maxWidth: 50,
                                    defaultWidth: 50,
                                    dataIndex: 'type',
                                    text: 'Type'
                                },
                                {
                                    xtype: 'gridcolumn',
                                    maxWidth: 50,
                                    defaultWidth: 50,
                                    dataIndex: 'currency',
                                    text: 'Currency'
                                },
                                {
                                    xtype: 'datecolumn',
                                    maxWidth: 125,
                                    defaultWidth: 125,
                                    dataIndex: 'date',
                                    flex: 2,
                                    text: 'Date',
                                    format: 'Y-m-d H:i:s'
                                },
                                {
                                    xtype: 'datecolumn',
                                    maxWidth: 125,
                                    defaultWidth: 125,
                                    dataIndex: 'time',
                                    flex: 2,
                                    text: 'Time',
                                    format: 'Y-m-d H:i:s'
                                },
                                {
                                    xtype: 'numbercolumn',
                                    maxWidth: 50,
                                    defaultWidth: 50,
                                    dataIndex: 'rate',
                                    text: 'Rate'
                                },
                                {
                                    xtype: 'numbercolumn',
                                    maxWidth: 65,
                                    defaultWidth: 50,
                                    dataIndex: 'bid',
                                    text: 'Bid'
                                },
                                {
                                    xtype: 'numbercolumn',
                                    maxWidth: 65,
                                    defaultWidth: 65,
                                    dataIndex: 'ask',
                                    text: 'Ask'
                                },
                                {
                                    xtype: 'numbercolumn',
                                    maxWidth: 65,
                                    defaultWidth: 65,
                                    dataIndex: 'high',
                                    text: 'High'
                                },
                                {
                                    xtype: 'numbercolumn',
                                    maxWidth: 65,
                                    defaultWidth: 65,
                                    dataIndex: 'low',
                                    text: 'Low'
                                },
                                {
                                    xtype: 'numbercolumn',
                                    maxWidth: 70,
                                    defaultWidth: 70,
                                    dataIndex: 'oneDayPrice',
                                    text: 'Onedayprice'
                                },
                                {
                                    xtype: 'numbercolumn',
                                    maxWidth: 85,
                                    defaultWidth: 85,
                                    dataIndex: 'oneDayChangePercent',
                                    text: 'PercentChange'
                                },
                                {
                                    xtype: 'numbercolumn',
                                    maxWidth: 80,
                                    defaultWidth: 80,
                                    dataIndex: 'oneDayChange',
                                    text: 'Onedaychange'
                                }
                            ]
                        }
                    ]
                },
                {
                    xtype: 'panel',
                    height: 503,
                    resizable: true,
                    title: 'Tab 3'
                }
            ]
        });


        me.callParent(arguments);
    }


});