I found ui.pager won't refresh itself when no record found.
It looks quite strange to user.
By default, it shows: << < 1 2 3 > >> Page 1 of 3, 6 items and two records shown
If I enter a X in Title filter input, then no record found, however pager is not changed, still shows Page 1 of 3, 6 items. I think it should show something like Page 0 of 0, 0 items, and without pages.
If I enter other filter with records found, pager will refresh properly