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Remove Variable Transformer

The Remove Variable component takes a Mule variable name and removes the variable from a Mule event.

Field XML Description

Display Name

doc:name

Customize to display a unique name for this component in Anypoint Studio. Defaults to Remove Variable.

Name

variableName

Name of the variable to remove. If the variable does not exist in the flow, the component logs a warning (WARN). Attempts to access the value of a variable that does not exist return a null value. See Example.

Example

This basic example shows how to remove a Mule variable from the flow:

<flow name="remove-variable-ex" >
  <scheduler doc:name="Scheduler" >
    <scheduling-strategy >
      <fixed-frequency frequency="10" timeUnit="SECONDS"/>
    </scheduling-strategy>
  </scheduler>
  <set-variable value='"value of my Mule variable"' doc:name="Set Variable"
                variableName="myMuleVar"/>
  <logger level="INFO" doc:name="Logger"
          message="#[vars.myMuleVar]"
          category="PRINT VALUE OF VARIABLE"/>
  <remove-variable doc:name="Remove Variable"
                   variableName="myMuleVar"/>
  <logger level="INFO" doc:name="Logger"
           category="ATTEMPT TO PRINT VALUE OF REMOVED VARIABLE"
           message="#[vars.myMuleVar]"/>
  <remove-variable doc:name="Remove Variable"
                   variableName="banana"/>
</flow>

The flow uses the following processors:

  • The Scheduler component triggers the flow.

  • Set Variable creates a Mule variable (myMuleVar).

  • The first Logger in the flow prints the value of the variable ("value of my Mule variable").

  • Remove Variable provides a string with the name of the variable (variableName="myMuleVar") to remove the variable from the Mule event.

  • The second Logger prints null because the Mule variable no longer exists.

  • The second Remove Variable logs a WARN message because it attempts to remove a Mule variable (banana) that does not exist in the Mule event.

The following example shows the logs for an execution of this flow:

INFO  2022-12-15 08:33:20,151 ...event: 2f65e920-7c96-11ed-97ec-147ddaaf4f97]
PRINT VALUE OF VARIABLE: "value of my Mule variable"

INFO  2022-12-15 08:33:20,155 ...event: 2f65e920-7c96-11ed-97ec-147ddaaf4f97]
ATTEMPT TO PRINT VALUE OF REMOVED VARIABLE: null

WARN  2022-12-15 08:33:20,156 ...event: 2f65e920-7c96-11ed-97ec-147ddaaf4f97]
...RemoveFlowVariableProcessor: There is no variable named 'banana'.
Check the 'variableName' parameter in the 'remove-variable' component at
remove-variable-ex/processors/4

See Also