type
AccessRule
AccessRule decides whether one field value may be created, read, or updated. Return false during a write to reject the operation, or during a read to omit the field from the response. Returning an error stops the operation. Field rules cannot return the query predicates supported by collection access rules.
Full signature
type AccessRule func(operation.Context) (bool, error)Related types
ContextContext describes one field callback at its current lifecycle phase. Root, Siblings and Prior are detached, immutable snapshots of field values; document metadata such as ID is available separately on Context. A callback changes its own value only through its return value.