VariableWriteCallback¶

Canonical path: o6.server.VariableWriteCallback

VariableWriteCallback ¶

Bases: Protocol

The shape of a Variable value-write implementation.

Registered with o6.write or Server.addVariable. The callback runs on the server's event loop, so it must not block.

__call__(node, value, *, range, session)

Accept or reject a write to the Variable.

Parameters:

Name	Type	Description	Default
`node`	`VariableNode`	The Variable being written.	required
`value`	`DataValue`	The requested `DataValue`.	required
`range`	`tuple[slice, ...] \| None`	The requested index range, or `None` for the whole value.	required
`session`	`Session \| None`	The writing session, or `None` for an internal write.	required

Returns:

Type	Description
`tuple[StatusCode]`	A one-tuple holding the StatusCode of the write.