scatter-valuefrom-wf2.cwl

#!/usr/bin/env cwl-runner
cwlVersion: v1.0
class: Workflow

inputs:
  inp1:
    type:
      type: array
      items:
        type: record
        name: instr
        fields:
          - name: instr
            type: string
  inp2:
    type:
      type: array
      items: string
outputs:
  out:
    outputSource: step1/echo_out
    type:
      type: array
      items:
        type: array
        items: string

requirements:
  - class: ScatterFeatureRequirement
  - class: StepInputExpressionRequirement

steps:
  step1:
    in:
      echo_in1:
        source: inp1
        valueFrom: $(self.instr)
      echo_in2: inp2
      first:
        source: inp1
        valueFrom: "$(self[0].instr)"
    out: [echo_out]

    scatter: [echo_in1, echo_in2]
    scatterMethod: nested_crossproduct
    run:
      class: CommandLineTool
      id: step1command
      hints:
        ResourceRequirement:
          ramMin: 8
      inputs:
        first:
          type: string
          inputBinding:
            position: 1
        echo_in1:
          type: string
          inputBinding:
            position: 2
        echo_in2:
          type: string
          inputBinding:
            position: 3
      outputs:
        echo_out:
          type: string
          outputBinding:
            glob: "step1_out"
            loadContents: true
            outputEval: $(self[0].contents)
      baseCommand: "echo"
      arguments:
        - "-n"
        - "foo"
      stdout: step1_out