Update docs to use hooks

[selbekk]

As of now, the main docs haven’t been updated to account for hooks. Especially the state & lifecycle section seems a bit misleading now.

I’d love to help out with a rewrite, but I’d love to hear your feedback on what should be changed and what should stay behind.

[saranshkataria]

Since we are having the discussion at #1782, closing this one out.

[selbekk]

Slightly different issue @saranshkataria - this pertains to the docs, not the tutorial

[saranshkataria]

ah, my bad. But why would we want everything to be hooks in the docs? There's a section about hooks and that is what it should be?

[selbekk]

On mobile now, but in short: if the Preferred Way of React going forward is using hooks for stuff like state and side effects, I think we should rewrite the docs so that they mirror that message. Right now, that’s not the case.

Have a look here: https://reactjs.org/docs/state-and-lifecycle.html

Class components and lifecycles definitely need to be documented, but perhaps not as... «the first choice», if you know what i mean.

[saranshkataria]

I don't think the docs should be preferring one way over the other yet, everyone is still figuring hooks out, but will reopen this issue to let other people share their opinions on it.

[selbekk]

As of now, though, the docs are preferring class components, by not even mentioning hooks (at least in that section)

[kachkaev]

RADME.md in facebook/react repo says:

We have several examples on the website. Here is the first one to get you started:
[a functional component]

Following the link takes a newcomer to a page where all components are classes. This is quite confusing. Given that the stateful logic can be expressed using hooks now, classes can be revealed much later.

[voluntadpear]

I feel the same about the Main Concepts docs. Especially the "State and Lifecycle" doc. I was expecting to see at least a mention about Hooks there. Newcomers to React (especially folks coming from other libraries) could choose to check the Docs instead of the Tutorial (depending on their style of learning) so the Hooks section being after Advanced Guides and even the API Reference makes them somehow easy to miss. Having a brief mention of Hooks as an alternative to classes could be really helpful.

[nickserv]

@saranshkataria

I don't think the docs should be preferring one way over the other yet, everyone is still figuring hooks out, but will reopen this issue to let other people share their opinions on it.

The hook docs recommend using hooks rather than classes for new components (see Should I use Hooks, classes, or a mix of both?). The docs should primarily focus on hooks to be consistent with this suggestion, and save time by not requiring users to learn classes before they can learn hooks.

With docs rewritten in hooks, we'd have to decide how to handle the old class docs. Is the class API going to change in the future, making it useful to maintain the original class docs in full as a separate verison? If not, should we stop updating the class docs or move them to a subsection of the hook docs (kinda like how hook docs are a subsection of the class docs now)?

[nickserv]

I'm making progress on converting the docs to use hooks instead of classes, and I'll submit a pull request when it's mostly complete. Then we can figure out if it's okay to replace the class docs or if the hook docs should be reworked in a different way.