I am trying to resume processing a topic at a particular point. My strategy is to have a predictable label on a rule in the topic and test to see if that rule exists, if it does then I want to do normal ^respond() processing starting at that point. My topic has keep and repeat in the topic specification. What I am seeing is that the ^respond(~topic.rulelabel) is always failing and I don’t know why.

The documentation for ^respond() states:

If a value designates a labelled or tagged rule (e.g., ~mytopic.mylabel or ~mytopic.1.0) then the system will skip over all rules until it reaches that rule, then begin linear scanning,

The documentation for ^available() state:

Sees if the named rule is available (1) or used up (0). If you supply the optional argument, the function will fail if the rule is not available.

When I run this code:

which refers to this topic and rule

I get this in my trace log.

I believe that I have found a work around!!

I would still like to know why the system behaves as described above.

The work around is.

Perhaps the call to ^available() counts as a match and thus turns off the rule.

I guess that I don’t have it fixed yet :-(
the below trace shows that the ^available and ^enable work fine but the ^respond is still failing.

?? is there a way to find out exactly why the rule is failing? :topicinfo indicates that the rule is enabled.
?? is there a problem calling ^respond from within an outputmacro: ?

First point, your rule will ALWAYS be available because the topic has KEEP on it.

Second, this simpler example worked for me:

u: (test)  $_goal = ^join(~jenkins . RESUME_GOAL)
if( ^available($_goal optionalfail)){
^nofail(TOPIC ^respond($_goal))
}

topic: ~jenkins keep repeat (get latest last build )
u: TRY_MATCH (  ) bad
u: RESUME_GOAL () we got here

and the code also works from inside an outputmacro.

Now, I’m not sure why you used $$_ as your prefix nor whether that confused the system.  Try my code first, or try your code changing the variable to a simple $_ variable.

Bruce,

I am using the $$_var because it is a local temporary variable. I will try with $_.

BTW, is there anyway to get the failure reason or catch the failure in the code at all besides ignoring it using ^nofail?

I ended up having my outputmacro call ^reuse($$_rule) and then had the rule look like this: