log.md

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<log>

Video version

Allows an application to generate a logging or debug message.

Here is an example:

<log label="DEBUG" expr="Entered 'State1'"/>

Output:

[Log] DEBUG: "Entered 'State1'"

Attribute Details

Name	Required	Type	Default Value	Description
label	false	string	empty string	A character string with an implementation-dependent interpretation. It is intended to provide meta-data about the log string specified by 'expr'.
expr	false	Value expression	none	An expression returning the value to be logged. See 5.9.3 Legal Data Values and Value Expressions for details. The nature of the logging mechanism is implementation-dependent. For example, the SCXML processor may convert this value to a convenient format before logging it.

Example

<scxml initial="Shape1" name="Scxml" version="1.0" xmlns="http://www.w3.org/2005/07/scxml">
	<state id="Shape1">
		<onentry>
			<log expr="Entered 'Shape1'" label="DEBUG"/>
			<raise event="error"/>
		</onentry>
		<onexit>
			<log expr="Exited 'Shape1'" label="INFO"/>
		</onexit>
		<transition event="error" target="Fail"/>
		<transition event="*" target="End"/>
	</state>
	<final id="End">
		<onentry>
			<log expr="Pass!" label="DEBUG"/>
		</onentry>
	</final>
	<final id="Fail">
		<onentry>
			<log expr="Failed!" label="ERROR"/>
		</onentry>
	</final>
</scxml>

Output:

[Log] DEBUG: "Entered 'Shape1'"

Internal Event: error, interpreter [Scxml]

[Log] INFO: "Exited 'Shape1'"

[Log] ERROR: "Failed!"

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