How to fire periodic actions using setTimeout and

问题:

How/Where can I dispatch actions periodically? Using recursive setTimeout to make a countdown.

Taken from the example, something similar to this:

// Can also be async if you return a function
export function incrementAsync() {
  return dispatch => {
    (function _r() {
      setTimeout(() => {
        // Yay! Can invoke sync or async actions with `dispatch`
        dispatch(increment());
        _r();
      }, 1000);
    })();
  };
}

So is this a good idea, or there is a better approach to this problem, like using middlewares or creating actions from somewhere else?

I prefer a generic version of this, where I can control start/stop of the timer via the store.

I've setup a sample implementation please take a look at https://gist.github.com/eguneys/7023a114558b92fdd25e

回答1:

The approach you suggest is fine, although a bit convoluted. In general, I'd set intervals inside component lifecycle methods (e.g. componentDidMount / componentWillUnmount) and avoid actions setting intervals on other actions.

If you absolutely need this flexibility, a better bet is to use Rx for async management, and dispatch the actions at the very end of observable chain. This way you use Redux where it shines (synchronous updates) and leave asynchronous composition to Rx.