hi leo,

it sounds like what you're really talking about is whether the filtering/sorting is performed on the client or the server. once the LabKey store has initially loaded, it's basically the same thing as the ArrayStore. You could create a LABKEY store and either:

1) i'm pretty sure if you just call store.filter('myField', 'value') it will perform that on the client. this isnt what you'd want 100% of the time, but perhaps some of the time. If you need to replicate more complex filters, like startswith, contains, etc then you'd just use a regex for filtering (ie. /^foo/i).

2) if you set the store's properties remoteFilter and remoteSort to false, it should sort client-side. i'm less certain how everything will behave without doing some testing, and could look into that if you like.

when we convert our API to Ext4 I'd love to see cleaner ways to handle manipulation of the store, but I think what you need is quite possible in the Ext3 store too.