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Arez Core
There is a newer version: 0.213
package arez.annotations;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Target;
import javax.annotation.Nonnull;

/**
 * Identifies method that is called when the {@link arez.ComputableValue} changes from the INACTIVE state to any other state.
 *
 * This method can only be associated with a {@link Memoize} annotated method that has 0 parameters.
 * This limitation is in place to limit implementation complexity and because no use case for this
 * functionality has been found.
 *
 * The method must also conform to the following constraints:
 * 
 * Must not be annotated with any other arez annotation
 * Must have either 0 parameters or a single parameter of type {@link arez.ComputableValue}
 * Must not return a value
 * Must not be private
 * Must not be static
 * Must not be abstract
 * Must not throw exceptions
 * Must not be for a {@link Memoize} method that has the {@link Memoize#keepAlive} parameter set to true
 * Must be accessible to the class annotated by the {@link ArezComponent} annotation.
 * 
 *   Should not be public as not expected to be invoked outside the component. A warning will be generated but can
 *   be suppressed by the {@link SuppressWarnings} or {@link SuppressArezWarnings} annotations with a key
 *   "Arez:PublicHookMethod". This warning is also suppressed by the annotation processor if it is implementing
 *   an interface method.
 * 
 * 
 *   Should not be protected if in the class annotated with the {@link ArezComponent} annotation as the method is not
 *   expected to be invoked outside the component. A warning will be generated but can be suppressed by the
 *   {@link SuppressWarnings} or {@link SuppressArezWarnings} annotations with a key "Arez:ProtectedMethod".
 * 
 * 
 */
@Documented
@Target( ElementType.METHOD )
public @interface OnActivate
{
  /**
   * Return the name of the ComputableValue that this method is associated with.
   * This value will be derived if the method name matches the pattern "on[Name]Activate",
   * otherwise it must be specified.
   *
   * @return the name of the ComputableValue.
   */
  @Nonnull
  String name() default "";
}