How does targets decide when to invalidate a targeting involving an online API call

[liutiming]

I have a function that calls an online API that involves computation from the value that I provided.

I wonder how hash value is determined in this case and if it is recommended to set tar_cue = "never" once the call has been done.

[wlandau]

The hash is determined by the local data that is downloaded. The target is invalidated when the local data changes, etc., but targets will not know about the external service whose API you called. Up to you whether to set mode = "never" in tar_cue(). If all you need is the data to exist and you do not care to synchronize your local copy with the latest online copy, that seems fine. Otherwise, you could use a custom cue, maybe a tar_age() target or tar_cue_age() cue from development tarchetypes if you want to check at regular time intervals.

[liutiming]

Thanks a lot!