Terminal Op Delegates

Terminal Op Delegates are a method of appending an arbitrary Op Chain to the end of the Op Tree that is generated from a node in the node graph.

A Terminal Op Delegate class should implement the TerminalOpDelegate interface, then an instance can be registered with RegisterTerminalOpDelegate

Terminal Op Delegates are responsible for caching their Ops. It is strongly encouraged for performance and memory management reasons that a Terminal Op Delegate should retain references to Ops it creates, then re-use/update them where possible, rather than creating new Ops on every evaluation.

API Reference

Nodes3DAPI.RegisterTerminalOpDelegate(name, terminalOpDelegate)

Registers the given TerminalOpDelegate under the given name.

A TerminalOpDelegate allows Terminal Ops to be appended to any Op Tree returned by nodes. The Op Args of these Ops can change arbitrarily, forcing the Op Tree to be recooked.

Parameters:

name (str) – A key used to identify the TerminalOpDelegate.
terminalOpDelegate (TerminalOpDelegate) – The TerminalOpDelegate to register.

Nodes3DAPI.UnregisterTerminalOpDelegate(name)

Unregisters a TerminalOpDelegate previously registered with RegisterTerminalOpDelegate().

Parameters:: name (str) – A key used to identify the TerminalOpDelegate to unregister.

Nodes3DAPI.GetRegisteredTerminalOpDelegateNames()

Return type:: list of str
Returns:: A list of names of every TerminalOpDelegate previously registered with RegisterTerminalOpDelegate().

Nodes3DAPI.GetRegisteredTerminalOpDelegate(name)

Return type:: TerminalOpDelegate
Parameters:: name (str) – A key used to identify the TerminalOpDelegate.
Returns:: The TerminalOpDelegate that was registered with RegisterTerminalOpDelegate() under the given name, or None if no Terminal Op Delegate was registered under that name.

class Nodes3DAPI.TerminalOpDelegates.TerminalOpDelegate.TerminalOpDelegate

Bases: object

Base class for a Terminal Op Delegate. A TerminalOpDelegate allows Terminal Ops to be appended to any Op Tree returned by nodes. The Op Args of these Ops can change arbitrarily, forcing the Op Tree to be recooked. These can be registered in the Nodes3DAPI using:

Nodes3DAPI.RegisterTerminalOpDelegate(
    'some name', someTerminalOpDelegate)

This base class is simply an interface, and does not provide any mechanism to store the Ops/Op Args in itself. That is the responsibility of the subclass.

appendOp(op, txn, port, graphState)

Appends the Terminal Ops to the given Op Tree. The port and graph state used to generate the Op Tree are provided.

Return type:

PyFnGeolib.GeolibRuntimeOp

Parameters:

op (PyFnGeolib.GeolibRuntimeOp) – An existing Op to be appended by the TerminalOpDelegate Ops.
txn (PyFnGeolib.GeolibRuntimeTransaction) – The Geolib3 transaction.
port (NodegraphAPI.Port or NoneType) – The port from which the Op Tree was generated, or None.
graphState (NodegraphAPI.GraphState) – The Graph State with which the Op Tree was generated.

Returns:

The last appended Op or the original Op if no Ops are appended.

Raises:

NotImplementedError – If not overridden by a subclass.

update()

Updates the internal data of the Terminal Op Delegate. This can be the Op and Op Args instances themselves or some data that can be used by appendOp() to instantiate these Ops and Op Args.

Return type:: bool
Returns:: True if any Ops or Op args from this TerminalOpDelegate changed.
Raises:: NotImplementedError – If not overridden by a subclass.