UseEffect class

A ReactterHook that manages side-effect.

The side-effect logic into the callback function is executed when dependencies of ReactterHook argument has changes or context of ReactterContext trigger didMount event.

UseEffect(() {
  print("Execute by state changed or 'didMount' event");
}, [state], this);

If the callback returns a function, then UseEffect considers this as an effect cleanup.

The effect cleanup callback is executed, before callback is called or context trigger willUnmount event:

UseEffect(() {
  print("Execute by 'didMount' event");

  return () {
    print("Execute by 'willUnmount' event");
  };
}, [], this);

RECOMMENDED: Use it on ReactterContext constructor:

class AppContext extends ReactterContext {
  late final state = UseState(false);

  AppContext() {
    UseEffect(() {
      print('state: ${state.value}');
    }, [state], this);

    Future.delayed(
      const Duration(seconds: 1),
      () {
        state.value = !state.value;
      },
    );
  }
}

If you need to execute the UseEffect's callback inmediately created, use DispatchEffect on context parameter:

UseEffect(
  () => print("Prompt execution or state changed"),
  [state],
  UseEffect.DispatchEffect,
);

or use mixin DispatchEffect:

class AppContext extends ReactterContext with DispatchEffect {
  AppContext() {
    UseEffect(
      () => print("Prompt execution or state changed"),
      [state], this
    );
  }
}

If you not put ReactterContext on the context parameter, should to call dispose method to clear any UseEffect's events.

Constructors

Properties

Methods

Operators

Static Properties

hooks library