[Feature Request] Add a clean way to extract failure cause from client side

[funkindy]

I need a straightforward way to show a failure reason on the client side.

AFAIK now there are a couple of ways to do it:

1. Dig into the history
2. try/except over await handle.result and then dig into the exception.

I wonder why there is no method on the handle to get current (not static) details and current summary?

I don want to do all the digging on the client side, i just want to put readable reason to current_* attributes and read them from the client.

Maybe some shortcut method to get latest event can work too.

What do you think?

Thank you!

[tconley1428]

Can you elaborate some? What type of failure are you talking about? Actual failure of the entire workflow? Something having failed but the workflow is still running?

i just want to put readable reason to current_* attributes and read them from the client.
I'm not sure I understand what this means. You want to set some state of your own the client can read? Or you want some notion of the current 'state' to be available for querying on the workflow handle?

[funkindy]

Hi! Yes, sorry. Id like to have a way to share current "whats happening" or final "whats failed" with the client (For UI or some decision-making on the client)

Now the client can get status and history of events. Status is too general, events are too technial and can be implementation specific.

I think it can be handy to let client obtain current_summary and current_details from the workflow.

I now use "upsert_memo" inside TWF and handle.describe().memo() on the client side as a workaround.

[cretz]

I need a straightforward way to show a failure reason on the client side.

Today success/failure result is only available by awaiting result or walking history (which is what result effectively does). We have opened temporalio/temporal#8608 to provide this type of information on describe of a workflow.

I wonder why there is no method on the handle to get current (not static) details and current summary?

There is no such thing as "current summary". For "current details", that's actually powered by a Temporal query named __temporal_workflow_metadata which returns a proto JSON'd result of https://github.com/temporalio/api/blob/master/temporal/api/sdk/v1/workflow_metadata.proto's WorkflowMetadata which includes current detail as obtained from the workflow code, it is not in history or on the server at any time.

You can write your own query that can return anything you want too and it can be called even after a workflow is closed.