This was originally posted as a twitter thread: https://twitter.com/chrisachard/status/1179015849459507200
Does Redux have you confused?
It can be simpler with the new Redux hooks.
🔥Here's a crash course into Redux, and how you can use it with React function components:
It's most often used with React (via react-redux)
This lets you access or change your state from ANY component in your tree
Your state lives in a central Redux store
That store is created with a function called a reducer
A reducer takes in a state and an action,
and returns the same or a NEW state
The store is given to your app using the
Provider from react-redux
Use the provider to wrap your entire app, so that any component in your app can access the store
To get data out of the store, use the
useSelector hook from react-redux
selector is just a fancy word for: "function that gets data from the store"
useSelector takes a callback, which gets the entire redux state, and you just pick out what you need for that component
All actions should have a 'type' key
They may also have additional keys (parameters)
Actions are not "called", but are "dispatched" to the reducers
type is what tells the reducer what to do (return a new state or the old one)
To change data in the store, first write your reducer:
Reducers are often written with switch/case statements, but don't have to be
They just have to take in an action and a state, and return a new state
It's important that reducers return a NEW state object (and not mutate the old one) so that your components will re-render when something changes
Don't set state values in reducers - only ever return a new state object with changed values
To dispatch an action, use the
useDispatch hook from react-redux
call useDispatch with an action object,
which will run through the reducers,
and will potentially change the state
All connected components (that call useSelector) will automatically get the new state
This is treated like props or state changing - useSelector will automatically detect changes and React will re-render the component
That's the basics!
Redux can be used in much more complex ways, but the core is always:
- dispatch an action to the store
- which may or may not change the state via reducers
- access that state with a selector
- and changes will automatically re-render your app
View and play around with the code used in this course on codesandbox:
Like this crash course?
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Thanks for reading!
Top comments (28)
Thank you so much. I have been trying to learn redux for the past month and was not understanding how to implement it. This is simply perfect. This is what exactly what I was looking for.
I can't Thank you enough. You are the best. 😍😍😍
Glad to help! 😁
Cool intro to hooks for redux!
Little comment: It would be even nicer if the code examples were not images so I could easily copy snippets (and that would also give more SEO probably). But no worries, I still enjoyed reading this.
(And thanks for contributing to DEV)
Yeah, that’s a good point... I do include a code sandbox link at the end, but I could put one for every step - I’ll think about that for next time (or could edit this one).
Glad it was useful!
I love the verry visual explainations with all that arrow pointer stuff :)
Glad to hear it!
Hey man! This article is awesome, I am currently learning Redux in React, Can I translate your article, learn, and then put it on the China Programming Forum website? Website Addr: segmentfault.com/ . And I'll keep original address in article.
Sure thing! That'd be neat :)
Before I read this article, I was extremely confused about Redux (coming from Vuex, you can Imagine the difference) - but this article laid it all out clearly, and now I have a decent understanding of redux. Thank you so much! :D
Thanks for good intro. I've been developing in NodeJS (and a number of other langs) for ages but React made me scratch my head. I felt old and dumb :) Now I start getting it.
BTW - what's the issue with those weird "s" characters you're using? I remember we had to write "s"-s this way at school (in Europe). How do you get these?
Glad you're starting to get it!
Ah, those "s" characters are because I turned on "ligatures" in codesandbox (which I used to make those screenshots). I think they're kind of fancy looking 😄
Are you using redux with React?
If you are, then React will respond to the data update by only re-rendering components that pull out data from the store that has changed.
If you aren't using React (it sounds like you aren't maybe, because you wrote your own callback that re-renders your UI?), then I can't help much - sorry! In that case you would need to write code to figure out which parts of the UI need to update. You shouldn't need to use two stores to do that - it's possible with just one.
Thank you very much for your response i really appreciate it!
I found it very useful and well written, thanks
Great writeup! Clearer and more helpful than some much longer pieces. Let me know when you do sagas!
The formal redux with React "Getting started" guide was confusing so I searched on this site and found your article. Fantastic guide to get started and a very accessible explanation. Thank you!
By the by what tool you have used for adding notes to the code in those images, it looks cool to me..
I take screenshots of the code and then open them in photoshop to add the arrows and notes. Kind of a lot of work! But I'm not sure if there's an easier way :)
Thanks! Exactly what i was looking for :D
Amazing explanation! You're really the best, dude!)
I'd love it if you wanted to dissect my Redux one line replacement hook... useSync