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Using the React Context API, the right way (a time saver)

Itay Schechner on August 05, 2021

Hey everyone! I'm Itay, a fullstack web developer who specializes in back-of-the-frontend code, particularly with React.js. Today, I'll teach you u...
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ncpa0cpl • Edited

Overall good article, but I have a big problem with this statement:

The Context API is the state-of-the-art way to manage state in React. It is an alternative to Redux, MobX, and a large variety of state management libraries made by the community.

No, Context API is not an alternative to Redux or MobX, Context API is not a state management tool, it has absolutely nothing to do with managing state.

Context API and state management libraries are supposed to solve two completely different problems.

State management library is intended to, well, manage state, so set the state, read the state and update the state.

Context API is intended to share a piece of data across many React components without prop-drilling. (Context does not "manage" anything)

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Chris Hansen

Hey great article D: So just to clarify, Context is not for state management, as you can handle state anyway you like, but the ContextProvider allows you to have access to that data anywhere without prop drilling? Is my mind in the right place? I know how to use it, I just hope I know WHY I'm using it LOL. Thanks ahead.

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ncpa0cpl

You are correct, except Context Provider does not allow to have access to that data anywhere. It's only within React Components that are descendants of that Provider.

What's most important Context does not give any option to access it's data outside the React tree (Redux and other State Management library do)

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Chris Hansen

Ahh okay gotcha. Perfectly said, I get it now. Thanks! 👌

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Alex Batalov

You absolutely wrong, thanks God we have RFC to mange context state changes github.com/facebook/react/pull/20646
Wait for a while to have ability to remove any state managers from your React app.

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ncpa0cpl

It's a pull request for an experimental feature therefore it's not really relevant to this discussion.

And even if this was already available in the stable version it doe not make Context a state management tool since it lacks the ability to do anything with the state it distributes.

To make things clear, Context API consists of(as of right now):

  • createContext method
  • useContext hook

And those provide you with a Context Provider, Context Consumer and the Context value.

None of the above allows for managing the state, there is nothing that would allow for updating state or adding side effects.

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Alex Batalov • Edited

This feature definitely will be added in stable version. Second argument as comparator will allow you to check is the target value in context is really changed. Isn't it the state manager behavior?

UPD: Oh, God, I was the one who was totally wrong. Don't believe empty promises, everybody, peace!

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Itay Schechner

You are absolutely right. Hooks are responsible for the state management in those examples.

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Itay Schechner

Not only useState. You have the useEffect hook, an essential hook for every context & hooks back-of-the-frontend code, the useMemo and useCallback hook that I highly recommend you to understand, and a lot more you can do with those.

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YouYi

You are right. I took a deep look of hooks.Basically, I noticed React separate the whole html, css structure from data. Then we can store data ,change data, update data, share data. That is state management, and all hooks serve for that.

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Tanzim Ibthesam

Well in React documentation its written React Hooks has been created to manage state and prevent from using 3rd party libraries like Redux

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Eric Bishard

Good article and I'm not going to get upset about the comment about it being an alternative for MobX and redux because I understood what you were saying you definitely have the ability to avoid those tools by simply using context and a lot of the times context API is used specifically for state management so I can read between the lines and I think you have some good examples in here too with the logical stuff again great article

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Moisés Rodríguez

A bit off topic, but I've been searching how you make those pretty code images and I can't find it hahaha.

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Buniamin Shabanov

There are extensions for vscode, like PolaCode and others.

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transli

You can use carbon.now.sh/

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Stephen Samra

Here you go: carbon.now.sh/

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payapula

Nice article. Learnt about a new pattern with respect to Contexts. Thanks for sharing! 🏅

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Itay Schechner

Oops:) forgot to insert that... Thanks for the feedback!

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Panos K.

Amazing article. Looking forward for typescript, icons and forms.

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khoan • Edited

wow, first time I come across this expression: <>{ condition ? children : null }. What's its name? Thanks.

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Itay Schechner

Ternaty operator
When you put it inside a React fragment, you ensure that the function will always return JSX.

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khoan

ah, I think, it should be: <>{ condition ? children : null }</>

Or, the closing </> is optional? Thanks.

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Itay Schechner

Yeah, you should close it. I'd review my code snippets again next time.

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Femi Obadimu

Nice nice..
An alternative to redux
..

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Thomas Moran • Edited

Wouldn't you still need to do a conditional render to show the Auth vs NotAuth components as shown in your third snippet?

Or would you plan on returning both and letting Context worry about which to show

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Itay Schechner

My solution is

<Authenticated>You're signed in</Authenticated>
<NotAuthenticated>
Oops, go sign in
</NotAuthenticated>
Enter fullscreen mode Exit fullscreen mode

The reason I like it so much is that you can use one without the other, like the example in the logout button.

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Dustin Subalee

How exactly is the Component Factory pattern you mentioned (coined?) different to HOC (Higher order component)?

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Itay Schechner

It's different because of the simplicity. The warpper won't need a higher order component, you just create it with one line of code.

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Ryan Jentzsch

For state management I recommend ReactN. Easier to use than Redux, lightweight, with all the features of Redux. github.com/CharlesStover/reactn