Is it OK for a reducer to listen to other actions?

问题

At the moment I'm creating actions and then a reducer to handle different parts of my app... the different domains.

My app lists classes and pupils.

Currently I have an action that the app has loaded so that I know when to remove the loading spinner, I have actions for classes and pupils. My problem is that I find I need to execute several actions in a row and am not sure if this is a valid way to use redux.

Here is an example function that dispatches several actions after the data is loaded:

/**
  * Callback used by readAppData.
  *
  * @param object ioResult An object: {success: boolean, errorObj?: object, data?: string}
  */
  dataLoaded(ioResult: Object) {
    if (ioResult.success === true) {
      this.props.dispatch(appActions.appHasLoaded());
      if (ioResult.data !== '') {
        const jsonData = JSON.parse(ioResult.data);
        this.props.dispatch(classActions.replaceClasses(jsonData.classes));
        this.props.dispatch(pupilActions.replacePupils(jsonData.pupils));
      }

    } else if (ioResult.errorObj.code === 'ENOENT') { // File doesn't exist.
      writeAppData('', this.dataSaved);
    } else { // Some other error.
      this.props.dispatch(appActions.appHasErrored());
    }
  }

I was thinking about putting the jsonData.classes and jsonData.pupils into the appActions.appHasLoaded() call and just have a new case for APP_HAS_LOADED in my classes and pupils reducers.

Is this a better approach? To reduce it down to one action? Having separate actions makes it easy to see what is happening... maybe in 6 months time I will have to look through my code to work out exactly what happens on APP_HAS_LOADED if I use it in other reducers. Also the data that is loaded on app start is going to expand beyond just classes and pupils so if I don't combine the calls there could soon be many more dispatches to make - maybe I can store the data in separate files and load each one one at a time which would also fix my problem of having to call mutiple actions in a row.

Is it OK to call dispatch multiple times?

回答1:

Yes, you can.

From Redux creator Dan Abramov:

Many reducers may handle one action. One reducer may handle many actions.

Referenced in Redux Docs

also, there is a conversation on github about this.

来源：https://stackoverflow.com/questions/48052571/is-it-ok-for-a-reducer-to-listen-to-other-actions

标签

reactjs

react-redux