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@ComponentId

The @ComponentId annotation can be applied to a single method in the component. The method must return a unique, non-null identifier for the component instance. This value will be converted to a string to create the names of the underlying ObservableValue, Observer and ComputableValue primitives.

The user typically makes use of this method to align the identifier of the Arez component with the underlying business identifier or the identifier in the system from which it was sourced. i.e. The Arez component will have the same id as the row in the database which the Arez component has been constructed to represent.

For example:

@ArezComponent
public abstract class Person
{
  private final int _id;

  Person( final int id )
  {
    _id = id;
  }

  @ComponentId
  public int getId()
  {
    return _id;
  }

  ...
}

It should be noted that even if the method annotated method is not publicly accessible, the value of the id can always be accessed using the Identifiable.getArezId(component) method.