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log(String, T): T

Without changing the value of the input, log returns the input as a system log.

Use this function to debug DataWeave scripts until a proper debugger is incorporated. The Logger component outputs the results through DefaultLoggingService in the console.


Name Description


A string that typically describes the log.


The value to log.


The following example logs the specified message. In the console, the Logger component’s DefaultLoggingService returns the message WARNING - "Houston, we have a problem." MuleSoft adds the dash - between the prefix and value.
While the Logger component’s LoggerMessageProcessor simply returns the value "Houston, we have a problem.", without the WARNING prefix.


%dw 2.0
output application/json
log("WARNING", "Houston, we have a problem.")


WARNING - "Houston, we have a problem."

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