Handler API

Handlers in mmodel represent different execution methods for the provided graph. Currently, all handlers are executed in topological order, inherited from TopologicalHandler.

Handler class

There are three required elements of a handler class/instance:

1. The handler should take “graph” and “returns” as two (and only) positional arguments.

2. The handler should define __signature__ with inspect.Signature object to allow signature detection with inspect.signature.

3. The resulting handler object should be callable.

Modify the Model class if these conditions cannot be satisfied.

Handler Data class and TopologicalHandler

Handler data stores the input value and all return values of the node execution. To define a custom handler, a Data class should be defined, and it should have __getitem__ and __setitem__ methods. If the Model inherits the TopologicalHandler, the class DataClass should be defined as the Handler data class.

See handler reference for the handler reference.