Package io.camunda.zeebe.engine.processing.deployment.model.transformer

Class VariableMappingTransformer

  • public final class VariableMappingTransformer
extends Object
    Transform variable mappings into an expression.

    The resulting expression is a FEEL context that has a similar structure as a JSON document. Each target of a mapping is a key in the context and the source of this mapping is the context value. The source expression can be any FEEL expression. A nested target expression is transformed into a nested context.

    Variable mappings: 

       source | target
   =======|=======
    x     | a
    y     | b.c
    z     | b.d
    FEEL context expression: 
       {
     a: x,
     b: {
       c: y,
       d: z
     }
   }

    Output variable mappings differ from input mappings that the result variables needs to be merged with the existing variables if the variable is a JSON object. The merging is done by calling the FEEL function 'put all()' and referencing the variable. 

       {
     a: x,
     b: if (b = null)
        then {
          c: y,
          d: z
        }
        else put all(b, {
          c: y,
          d: z
       })
   }

    • Constructor Detail

      • VariableMappingTransformer

        public VariableMappingTransformer()

    • Method Detail

      • transformInputMappings

        public io.camunda.zeebe.el.Expression transformInputMappings​(Collection<? extends ZeebeMapping> inputMappings,
                                                             io.camunda.zeebe.el.ExpressionLanguage expressionLanguage)

      • transformOutputMappings

        public io.camunda.zeebe.el.Expression transformOutputMappings​(Collection<? extends ZeebeMapping> outputMappings,
                                                              io.camunda.zeebe.el.ExpressionLanguage expressionLanguage)