Macros

CDAP Macros can be specified within a condition expression. When a macro is specified in a condition, the data pipeline system will substitute a macro with the value specified at the runtime before the expression is compiled and executed. This provides a way for lazy substitution for the parts of the expression. Following are some of the examples for reference:

  runtime['$variable1'] > token['$stage']['$variable2']

Macros $variable1, $stage and $variable2 are substituted before the compilation of expression. Let's assume the value associated with the macro $variable1 is input, $stage is Data Quality and $variable2 is output. Then the expression is converted at runtime to

runtime['input'] > token['Data Quality']['output']

Then, there should exist another runtime argument named input that should a numeric value and same holds true for plugin Data Quality that emits value for output.