how to write a numeric trigger on a log item ?

[tconway]

From 2.4 (the release I am on) forwards, the doc for log items givesthis example for a Item monitoring a log for a numeric value ...

log[/path/to/the/file,"large result buffer allocation.*Entries: ([0-9]+)",,,,\1]

and claims:

with the ability to extract and return a number, the value can be used to define triggers.

But trying to define a trigger using this Item will not allow me to use any numeric functions

{my-host:log[/opt/myCompany/myApp/log/app.log,"APP Rest-Api STATS: \/events ([0-9]+) ([0-9]+) ([0-9]+) ([0-9]+)",,,,\4].max(300)}<1000

This trigger expression fails with:

Cannot implode expression
Incorrect item value type "Log" provided for trigger function "max(300)"

how can I do math with the numerical values extracted from the log ?

[tconway]

reply to myself with a better question

Ok, so it seems all a log item can do is record text, even if it is actually a number that has been extracted.

Is there any way to write a trigger script such that it can take that log item's text and then write a (new) numerical item back to the database for another trigger to use ?