Descriptor and Metadata

A Descriptor represents one bound occurrence of an Action in a run descriptor tree. Metadata carries the per-occurrence identity and live execution state for that descriptor.

Reusing the same Action instance in multiple locations creates distinct descriptors with independent execution state.

import org.paramixel.api.Descriptor;
import org.paramixel.api.action.Metadata;

Descriptor

public interface Descriptor {
    Optional<Descriptor> parent();
    Metadata metadata();
    default Optional<Descriptor> before();
    List<Descriptor> children();
    default Optional<Descriptor> after();
}

Method	Description
parent()	The parent descriptor, or empty for the root
metadata()	The per-occurrence identity and execution state
before()	The before-child descriptor (Lifecycle, Static, Instance); not included in children()
children()	The body child descriptors in discovery order; does not include before or after
after()	The after-child descriptor (Lifecycle, Static, Instance); not included in children()

Descriptors are read-only through this interface. The framework creates and mutates descriptors during discovery and execution.

Tree navigation

void printTree(Descriptor descriptor, String indent) {
    var meta = descriptor.metadata();
    System.out.println(indent + meta.name() + " [" + meta.kind() + "] " + meta.status().name());
    descriptor.before().ifPresent(before -> printTree(before, indent + "  "));
    for (Descriptor child : descriptor.children()) {
        printTree(child, indent + "  ");
    }
    descriptor.after().ifPresent(after -> printTree(after, indent + "  "));
}

Metadata

public interface Metadata {
    String id();
    String name();
    String kind();
    String className();
    Status status();
    Mode mode();
    Duration runDuration();
    Optional<String> message();
    Optional<Throwable> throwable();
    boolean isCompleted();
}

Method	Description
id()	Generated execution-occurrence identifier, unique across the current run
name()	The action display name
kind()	The action kind (e.g. "Step", "Lifecycle", "Parallel")
className()	The fully qualified runtime class name of the action
status()	The current execution status
mode()	The execution mode (RUN, SKIP, ABORT)
runDuration()	The local run duration measured for this descriptor
message()	The optional status message
throwable()	The optional throwable recorded for this descriptor
isCompleted()	Whether the descriptor has reached a terminal status

Identity vs state

Identity fields (id(), name(), kind(), className()) are immutable. State fields (status(), mode(), runDuration(), message(), throwable(), isCompleted()) are updated during execution and are thread-safe.

Execution identifier

The identifier is generated per execution occurrence and is unique across the current run. Running the same Action instance twice produces different identifiers. The @Paramixel.Id annotation and AnnotationResolver.byId() are separate discovery concepts and do not imply execution identifiers.

See Result for how to access the root descriptor from a run result.