The syntax of an explicit logging
...
expression is:
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<expr>.klog(<message>) |
where <expr>
is any valid KRL expression. The expression is returned, and something like the following is added to the console log (and the "Logging" tab of the UI if enabled):
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[KLOG] <message> <expr converted to a string> |
The syntax of an explicit logging statement in the postlude is:
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log <level> <expr> |
where where <level>
is one of info
, warn
, error
, or debug
; and <expr>
is any valid KRL expression that results in a string (or something that can be cast as a string such as a number). Explicit logging places statements also place the log message in two places:
...
the console log, and the "Logging" tab of the UI if enabled.
The following example would place a string with the value of a variable named query in named query
in the log if the rule fired:
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fired { log debug "query:"+query }
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The following would only log with an empty query:
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fired { log debug "Empty query" if(query like "^$") } |
The following rule is selected when an http:post()
event is seen with a status code indicating an error. The error is logged and then processing is stopped.
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rule r3 is active {
select when http post label re#ex# status_code re#([45]\d\d)# setting (status)
noop();
fired {
log error <<Error: #{status}: #{event:attr("status_line")}>>
last;
}
} |
Another approach to logging would use explicit error handling.See Debugging KRL for more information on debugging tools.