Sencha grid aggregate store entries - extjs

Question

Let's assume I have a store:
Buyer,Good,ItemCount,ItemPrice
{'Alice','Apple',5,$.25}
{'Bob','Pear',2,$.35}
{'Bob','Banana',5,$.25}
{'Bob','Pear',4,$.35}
{'Eve','Grapefruit',2,$.40}
And I have a grid in which to display this store's content, and at least a dozen functions scattered all over the place that change this store, changing filters, reloading data from the server, etc.
Is there a fast way to add another grid, which shows every good in a row and every buyer in a column, and how many items of that kind everyone bought in total? This grid should update whenever the original grid is updated.
The way I know, this would require another store, and then I would have to attach to the originalStore's datachanged and filterchanged event and populate the new store by hand every time? Or is there some other solution?
EDIT: I am now looking at pivot grid, as suggested by the first answer, and I have to expand my example a bit, as I stumbled upon a problem I didn't see before:
Buyer,Good,ItemCount,ItemPrice
{'Alice','Apple',5,$.25}
{'Bob','Pear',2,$.35}
{'Bob','Banana',5,$.25}
{'Bob','Pear',4,$.35}
{'Eve','Grapefruit',2,$.40}
{{'Alice','Bob'},'Candlelight Dinner Set',1,$45}
{'Eve',{'Ski mask','Baseball bat'},1,$65}
{'Francis',{'Ski mask','Ski poles'},1,$80}
Where I would want the dinner to show up at both Alice and Bob, and the products sold in a bundle to show up separately.

Answer 1

Try to use PivotGrid for your purpose:
var pivot = new Ext.grid.PivotGrid({
store: yourStore,
aggregator: 'sum',
measure: 'ItemCount',
leftAxis: [
{
dataIndex: 'Buyer'
}
],
topAxis: [
{
dataIndex: 'Good'
}
]
});
Official Pivot Grid Links:
Documentation (Sencha Docs 5.1)
Announcement (Sencha Blog)
Download (Free 30-Day Evaluation)