Can I dispatch an action in reducer?

is it possible to dispatch an action in a reducer itself? I have a progressbar and an audio element. The goal is to update the progressbar when the time gets updated in the audio element. But I don’t know where to place the ontimeupdate eventhandler, or how to dispatch an action in the callback of ontimeupdate, to update the progressbar. Here is my code:

When should I add Redux to a React app?

I’m currently learning React and I am trying to figure out how to use it with Redux for building a mobile app. I’m kind of confused on how the two are related/usable together. For example, I completed this tutorial in React, but now I want to play around with adding some reducers/actions to that app and I am not sure where those would tie in with what I’ve already done.

Accessing a reducer state from within another reducer

I have a reducer whereby I am retuning the appropriate state when an action is dispatched. Now I am calling an API at regular intervals so the result will trigger an action again and again. So what I want is that if the reducer state already has data then another reducer doesn’t show the state as loading while the call is sent. It must maintain its loading state when receiving data the first time only. I hope I am able to explain it properly