This topic describes how to call an ETL task from within another ETL process by using a <taskref> that refers to org.labkey.di.steps.QueueJobTask.

• QueueJobTask Reference
• Standalone vs Component ETL Processes
• Reference Generated Files

QueueJobTask Reference

Reference the ETL process you wish to queue up by module name and file name, using the pattern "{MODULE_NAME}/FILE_NAME". For example, to queue up the process MaleNC.xml in the module etlmodule, use the following:

<transforms>
    ...
    <transform id="QueueTail" type="TaskrefTransformStep">
        <taskref ref="org.labkey.di.steps.QueueJobTask">
            <settings>
                <setting name="transformId" value="{MODULE-NAME}/MaleNC"/>
            </settings>
        </taskref>
    </transform>
    ...
</transforms>

An ETL process can also queue itself by omitting the <setting> element:

<transform id="requeueNlpTransfer" type="TaskrefTransformStep">
    <taskref ref="org.labkey.di.steps.QueueJobTask"/>
</transform>

Standalone vs. Component ETL Processes

ETL processes can be set as either "standalone" or "sub-component":

• Standalone ETL processes:
• Appear in the Data Transforms web part
• Can be run directly via the user or via another ETL
• Sub-Component ETL processes or tasks:
• Not shown in the Data Transforms web part
• Cannot be run directly by the user, but can be run only by another ETL process, as a sub-component of a wider job.
• Cannot be enabled or run directly via an API call.

<etl xmlns="http://labkey.org/etl/xml" standalone="false">
    ...
</etl>

Reference Generated Files

If you expect a file output from one ETL to be shared/consumed by a different ETL in a sequence, all ETLs in the chain must use the loadReferencedFiles attribute. Learn more here:

• Load Referenced Files

Related Topics

• ETL: Extract Transform Load
• ETL: User Interface
• ETL: Attributes: ETL attributes including standalone and loadReferencedFiles.