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Handlers and opening

An entity handler defines what Reactor should do when a user opens an entity. This keeps trees, search results, cards, and selectors independent of workspace placement.

The core behavior​

Extend EntityHandlerComponent to define two things:

  • openEntity(event), which performs the behavior;
  • getDescription(entity), which describes that choice in UI.

The event includes the entity, pointer position, and action source. A definition may register several handlers. The preferred option marks a default, and workspace preferences can choose another handler where supported.

Inline callback handlers​

InlineEntityHandlerComponent is the direct callback derivative:

this.registerComponent(
  new InlineEntityHandlerComponent<TodoModel>({
    desc: { key: 'select-todo', label: 'Select todo' },
    cb: ({ entity }) => this.todoStore.setCurrent(entity)
  })
);

Use it for small behaviors that do not need to be reusable Reactor actions.

Action-backed handlers​

EntityActionHandlerComponent delegates opening to an EntityAction:

this.registerComponent(new EntityActionHandlerComponent(SetCurrentTodoItemAction.ID));

Use this derivative when opening should share action validation, metadata, shortcuts, or invocation behavior. Reactor supplies the opened entity as targetEntity.

Opening is distinct from contextual actions. Register other applicable action IDs with registerAdditionalAction() on the definition.