transformer_task.md

TransformerTask

Passes the input through a chain of transformers and outputs the result. This is the main way to use transformers inside a process.

Task reference

• Service: CleverAge\ProcessBundle\Task\TransformerTask

Accepted inputs

mixed: it must match the expected input of the first transformer of the chain.

Possible outputs

mixed: result of the last transformer of the chain. With an empty transformers list, the input is output unchanged.

If a transformer fails, the resulting TransformerException is set on the state (with the original error message added to the error context as error) and handled according to the task error_strategy.

Options

Code	Type	Required	Default	Description
transformers	array		[]	Ordered map of transformer code => options, or list of transformers, see TransformerTrait

Examples

• Decode a JSON string into an associative array

# Task configuration level
json_decode:
  service: '@CleverAge\ProcessBundle\Task\TransformerTask'
  options:
    transformers:
      callback:
        callback: json_decode
        right_parameters: [true]
  outputs: [dto]

• Map an array to a new structure, chaining the same transformer twice with the # suffix

# Task configuration level
transform:
  service: '@CleverAge\ProcessBundle\Task\TransformerTask'
  options:
    transformers:
      mapping:
        mapping:
          name:
            code: '[firstname]'
            transformers:
              trim: ~
      callback#1:
        callback: array_filter
      callback#2:
        callback: array_reverse
  outputs: [load]

• Same chain using the list syntax: the same transformer can be used several times without suffix

# Task configuration level
transform:
  service: '@CleverAge\ProcessBundle\Task\TransformerTask'
  options:
    transformers:
      - mapping:
          mapping:
            name:
              code: '[firstname]'
              transformers:
                - trim
      - callback:
          callback: array_filter
      - callback:
          callback: array_reverse
  outputs: [load]

See MappingTransformer and generic transformers.