Pin to metadata

Stores the record passing through in a named property of the flow metadata and forwards it unchanged. Later components and scripts of the same request can read the value from the metadata without a direct connection, for example to combine the original request with a later response.

Pins

Pin	Kind	Types	Description
Input	input	any	The record to store. Its type becomes the type of the metadata property.
Output	output	same as input	The unchanged record, with the metadata now containing the stored value.

Configuration

Field	Type	Default	Description
PropertyName	string (identifier)		Required. Name of the metadata property, a valid C# identifier unique within the flow metadata. Changing it regenerates the metadata property.

Behaviour

• Reconfigure (changing PropertyName or pressing its reconfigure button) adds a property PropertyName to the flow's metadata type <flow namespace>.FlowMetaData, typed as the input connection's type (Viaducta.TypeSystem.Metadata.NoInputData when the input is not connected). The property belongs to this component; renaming replaces it.
• For each record the value is stored in the metadata (wrapped values are unwrapped first), then the record is sent to Output with the same metadata.
• Downstream, read it in scripts as metaData.<PropertyName> after casting the metadata to the flow's FlowMetaData (as the Decision router template does), or select it wherever metadata properties are offered.
• On start the plugin checks that the property exists on FlowMetaData and that its type matches the input connection's type; otherwise the flow fails to start ("The input type does not match metadata ..., reconfigure the pin component").

Notes

• After changing the type of the input connection, reconfigure the component so the metadata property gets the new type.
• The value is stored per request (in that request's metadata). Components that create new metadata (for example a Plugin port request, or Timer-started branches) do not see it.
• The stored object is the same instance as the forwarded record; changes made downstream to the record are visible through the metadata property as well.

Example

{ "PropertyName": "OriginalRequest" }

Http listener → Pin to metadata → Http client → Script (uses metaData.OriginalRequest) → Http response