Error

Throws a configurable error when a record reaches it. Use it to end a request with a failure (validation failed, not found, ...) that upstream error handling (Try catch, Retry, HTTP listener error response) reacts to.

Pins

Pin	Kind	Types	Description
Input	input	any	Every record raises the error.

Configuration

Field	Type	Default	Description
Message	string (max 2048), exception selector	Default	Required. Error message. Default (any case) or empty generates "Exception occured on flow <flow> and component <component> at <date>". The editor offers predefined error types that fill Message and Code.
Code	integer	500	Required. Error code attached to the error, also used as the HTTP status code. 0 is replaced by 500.

Behaviour

• Throws a Viaducta.Plugin.Design.RecoverableFlowException with Message, Code, and the flow and component name.
• The error travels back along the call chain to the components that called this one. The first component that handles errors receives it: a Try catch upstream routes the record to its Catch pin (metadata Error holds the exception); a Retry upstream retries; otherwise the error is logged as unhandled for this request.
• The error is recoverable: the flow keeps running and processes further records. (An UnRecoverableFlowException, raised by the system for e.g. failed expressions or missing connections, instead stops the flow and is not passed to Try catch.)
• The error is logged once by the system where it occurs.

Notes

• Message and Code can be expressions, e.g. to include values from the record.
• The exception's "use code as HTTP status" flag is set: an HTTP listener that answers with the error uses Code as the status (for example 404). Use HTTP status codes in Code when the flow serves HTTP.
• In the Try catch Error metadata, FlowName and ComponentName are set but FlowId and ComponentId are empty for errors from this component.
• The generated default message contains only the date, not the time.

Example

{ "Message": "Order not found", "Code": 404 }

Http listener → Try catch → (Try) Database reader → If (no rows) → Error ; (Catch) → Http response