Coding

An Introduction to Redux

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Redux’s ideology is a unidirectional data flow. This pattern reduces long term complexity, encourages re-usability, and generally discourages spaghetti code. 🍝

Video Series: https://egghead.io/courses/getting-started-with-redux

Terms & Descriptions

The core of everything is the Store, Action, and Dispatch. In its simplest form it’s all you technically need. From there Thunks & Sagas enhance the the tooling around the Dispatching of Actions.

Store

  • A singleton object/state for the app.

Action

Dispatch

  • You “Dispatch an Action to the Store” to update the store.
  • Dispatch sends the Action payload through the Reducer.

Reducer

  • Receives the Action payload from Dispatch and modifies the Store.
  • Reducers contain no business logic, they only modify the Store described in the Action

Thunk

  • Considered the old way, but sometimes still has great applications in simple cases.
  • You can “Dispatch a Thunk to either access state or do ajax work”
  • Within a thunk you can call additional Dispatch
  • Within a thunk you can access the state of the store.
    • Good for conditionally firing subsequent api calls, or dispatches.
    • Good for pulling together data from the store into a dispatch.
  • Good for very simple ajax calls, you can Dispatch Actions from ajax response
  • Best way to understand Thunks in my opinion is to look at the 10 lines of source code:

Saga

  • Regarded as a better replacement for Thunks
  • Can require more effort than Thunks to understand, and build.
  • Within a Saga you can access the state of the store.
    • Great for conditionally firing subsequent api calls, or dispatches.
    • Great for pulling together data from the store into a dispatch.
  • Sagas can subscribe to listen and fire when some Actions have been Dispatched
  • Great for moving side effects to be self contained instead of sprinkled throughout the app
  • Provides great debounce / cancel / takelatest logic nearly for free.
  • Can do long running / scheduled Actions
  • https://redux-saga.js.org/docs/introduction/BeginnerTutorial.html

(cover photo credit: Jonathan Stassen / JStassen Photography)