Is there any quick shortcut way to remove all lines from a sublist (in my case, a list of child custom records on a parent custom record)?

you can delete the child custom records instead? or break the parent child relationship if you want to keep the records. but that might be slower... I doubt it would trigger sublist changed cos you'd be doing it in the record of the child not the sublist of the parent.

yeah I’m deleting in the console for now but that’s also slow, there are like 1400 children

when I've done this before I set my loop up to go backwards so the line number reference don't get messed up

just looking for a nice solution for the user when they need to clear the list

LOL well yeah deleting 1400 records, isn't gonna be quick any way you try to do it.

I’ve already written a little mini CSV-import that they can use to populate the sublist from right within the parent record while they are editing, just don’t have an equivalent to clear it out.

what's the issue with sublist changed firing?

No shortcut I'm aware of; you'll have to build it. Personally, for that volume of records, this is not something I'd try to tackle client-side - particularly on a custom sublist since those records exist on their own unlike a transaction line.

it’s a rare occurrence that this would come up but still annoying when it does!

The SAFE Guide has a strategy for mass create/update of records using Parent-Child relationships, but I don't believe you can delete with the same approach.

I'd be curious on what that child record trick does if you remove the lines - does it leave the children abandoned?

I would bet it does

That’s a sneaky little trick to do many creates/updates, I didn’t know about that. Makes sense though. Doesn’t really solve my issue but good to know about that!