Transformers

Connectors support Mapping and Service transformers for modifying messages as they flow through a connector.

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Mapping transformer

The mapping transformer uses Bloblang, a powerful declarative language for data transformation.

Configuration

Name	Type	Optional	Secret	Description
sourcecode	string	no	no	Bloblang mapping code that transforms messages.

Examples

Add fields to a message:

mapping:
  sourcecode: |
    root = this
    root.id = uuid_v4()
    root.processed_at = timestamp_unix()

Restructure a message:

mapping:
  sourcecode: |
    root = this
    root.user = {
      "name": this.firstName + " " + this.lastName,
      "email": this.email.lowercase()
    }
    root.metadata = {
      "source": "connector",
      "version": 1
    }

Handle missing values:

mapping:
  sourcecode: |
    root = this
    root.name = this.name.or("Anonymous")
    root.score = this.score.catch(0)

Delete sensitive fields:

mapping:
  sourcecode: |
    root = this
    root.password = deleted()
    root.ssn = deleted()

See the Bloblang Reference for the complete language documentation.

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Service transformer

The service transformer sends each message to a NATS service and uses the response as the transformed message.

Configuration

Name	Type	Optional	Secret	Description
endpoint	string	no	no	The NATS subject where the service receives requests.
timeout	string	yes	no	Maximum time to wait for a response. The value defaults to 5s.

Example

service:
  endpoint: 'transform.enrich-user'
  timeout: '10s'