I deleted a number of items off a long checklist. It is possible for me to retrieve them or is it a case of typing them all in again?
Sometimes the items on a list are too numerous or complicated to remember. If you have Trello on your phone, you can at least retrieve the old list so you can retype the items on your computer. If the phone is offline it can still retrieve Trello lists it has previously accessed. If you turn off Wifi and Cellular (or put it in flight mode) before opening Trello, it will pull up the last version of the list you used. This will only work for lists you frequently access with your phone (and for the OP the original data will be long gone) but it can be done -- I just retrieved about 60 items with URLs and contact addresses using this trick. To repeat, however, you still have to manually re-enter the items.
Unfortunately, according to Trello Help - Archiving and Deleting Cards
There is no way to get a deleted card back. It will not show up in any search results and actions associated with it will by removed from the activity stream.
So it looks like you will have to manually add those items again.
Note, I couldn't up vote or comment due to my account being too new, but "lifesblackblood"'s answer does work.
Steps: After deleting the checklist from a card (note there was a message that warned you there was no way to recover this).
Pre-work: Hope you previously opened the Card (e.g. checklist) prior to deleting the checklist. If you edited the checklist on your computer between opening it on your phone and deleting it, the older version will be what is stored.
- Turn on airplane mode. Make sure wifi is off so you have no connection to the internet.
- Navigate to the board/list/card with the deleted checklist
- Open up Excel or Trello on a computer and transcribe the list
- optional if used Excel: copy and paste the cells into a new checklist. Hit Add. Trello will automatically separate each line into a new checklist item.