Overview:

We can call a runtime parameter from within an expression language function by simply entering the parameter name. 

The semantic of  ${PARAMETER}  is that PARAMETER is the expression to be evaluated. ${ and } are quotes around the expression to mark where it starts and where it ends. 

For example, the following expression returns the value of the JDBCConnectionString runtime parameter:

 ${record:value(JDBCConnectionString)}

Use case:

We want to create orchestration pipelines which have multiple Job Start stages to run jobs, and we want to specify between DEV and PRD. If we have two jobs for the same pipeline, one with the keyword "DEV" and on with "PRD", we want to use runtime parameter to determine which job the Start Jobs stage runs.

Solution:

We can set a parameter called ENV and call it either "DEV" or "PRD".

Then, in the Start Jobs stage, we use a concat function to try to concatenate the job name with the ENV parameter like this:

${str:concat("Job for ", ENV})}