How to clear and set the Custom Field to the same value to trigger an automation?

[Louis Rausch]

I want to implement a parent-child system where I link cards together to provide a better overview. For context, there are currently over 1500 active cards. I have the following automation in place:

when custom field "Unternehmen" is set in a card in list "🇩🇪",

find a card titled "{customfieldvalue}"

and link the cards together

However, this only works when I import new data into the list. Since Trello doesn't support actions on events that occurred before the automation was created, I'm stuck with 1500 cards that can't trigger the automation.

My question is: Is there an automation that can clear the custom field value and then set it to the same input to trigger the automation?

[Theodoro Reato]

Hi Louis, 

Unfortunately, at the moment this isn't possible. You can only gather the information of a Custom Field to add to a field if the Custom Field was the trigger and then use the variable you mentioned: "{customfieldvalue}". 

More information: https://support.atlassian.com/trello/docs/working-with-custom-fields/

I hope this helps. Have a good day.