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#prefect-community
Title
# prefect-community
j
Jason Damiani
07/17/2019, 3:52 PMHey all, I'm attempting to use a state handler to update a database for Flow state transitions to Running, Failed, and Successful. I need to use a Flow parameter result to make the update, which I can retrieve from the state result for Failed and Successful, but its not clear to me how to do this for the Running state, which has NoResultType
Copy code
def handle_state(flow, old_state, new_state):
def param_value_for(param_name, state):
p = next(filter(lambda k: k.name == param_name, new_state.result.keys()))
r = state.result[p]
return r.result
if new_state.is_running():
foo = param_value_for('foo', new_state)
print('Starting to run')
elif new_state.is_failed():
foo = param_value_for('foo', new_state)
print(f'We have a failure for {foo}')
elif new_state.is_successful():
foo = param_value_for('foo', new_state)
print(f'We have a success for {foo}')c
Chris White
07/17/2019, 4:00 PM
Hey @Jason Damiani - take a look in
prefect.context Copy code
p = prefect.context.get("parameters", {}).get(param_name)j
Jason Damiani
07/17/2019, 4:01 PMah cool, thanks. I figured there must be an easier way
c
Chris White
07/17/2019, 4:01 PM
yea np!
j
Jason Damiani
07/17/2019, 4:22 PMAre parameters not documented here because they aren't always available in the context? https://docs.prefect.io/api/0.6.0/utilities/context.html#context-2
c
Chris White
07/17/2019, 4:33 PM
That’s a great question; they should always be in context during a flow run, so that’s an oversight! I’ll update
j
Jeremiah
07/17/2019, 6:31 PM
@Chris White maybe we should also start populating that list with all the Cloud variables that are available as well? Run ID, etc.
c
Chris White
07/17/2019, 6:58 PM
yea that’s a good idea, i’ll get that going this afternoon
j
Jason Damiani
07/17/2019, 7:10 PM👍
c
Chris White
08/05/2019, 9:41 PM
@Marvin archive “Issue accessing Flow Parameters from within a state handler”
m
Marvin
08/05/2019, 9:41 PM