here's the full code including the tooltip scan:
https://github.com/obble/iipui/blob/...poweritems.lua
and an example of how the tooltip for the item im scanning for is formatted in-game (minus the item level line that wowhead inserts):
the break on first return is intentional. its a single action button that displays the first found instance of an item with that matched string (an artifact power item) in the inventory. as i see it there's no point iterating after that, and once the item is used then the function runs again and picks up the next one or runs through with nothing found, and the button doesn't show.
this works fine in practice, unless there's two of the same item in sequence in the container (ContainerFrame1Button1 has conjured mana biscuit, ContainerFrame1Button2 has... conjured mana biscuit) wherein either the hyperlink or the id seems to fail or conflict somehow, meaning the tooltip isn't populated with information and returns nil.