After speaking with @timneutkens, this PR provides a smoother experience to users trying to migrate over to app without affecting users in pages.
This PR adds a new export available from `next/compat/router` that exposes a `useRouter()` hook that can be used in both `app/` and `pages/`. It differs from `next/router` in that it does not throw an error when the pages router is not mounted, and instead has a return type of `NextRouter | null`. This allows developers to convert components to support running in both `app/` and `pages/` as they are transitioning over to `app/`.
A component that before looked like this:
```tsx
import { useRouter } from 'next/router';
const MyComponent = () => {
const { isReady, query } = useRouter();
// ...
};
```
Will error when converted over to `next/compat/router`, as `null` cannot be destructured. Instead, developers will be able to take advantage of new hooks:
```tsx
import { useEffect } from 'react';
import { useRouter } from 'next/compat/router';
import { useSearchParams } from 'next/navigation';
const MyComponent = () => {
const router = useRouter() // may be null or a NextRouter instance
const searchParams = useSearchParams()
useEffect(() => {
if (router && !router.isReady) {
return
}
// In `app/`, searchParams will be ready immediately with the values, in
// `pages/` it will be available after the router is ready.
const search = searchParams.get('search')
// ...
}, [router, searchParams])
// ...
}
```
This component will now work in both `pages/` and `app/`. When the component is no longer used in `pages/`, you can remove the references to the compat router:
```tsx
import { useSearchParams } from 'next/navigation';
const MyComponent = () => {
const searchParams = useSearchParams()
// As this component is only used in `app/`, the compat router can be removed.
const search = searchParams.get('search')
// ...
}
```
Note that as of Next.js 13, calling `useRouter` from `next/router` will throw an error when not mounted. This now includes an error page that can be used to assist developers.
We hope to introduce a codemod that can convert instances of your `useRouter` from `next/router` to `next/compat/router` in the future.
Co-authored-by: JJ Kasper <22380829+ijjk@users.noreply.github.com>
This adapts the new client hooks of `usePathname`, `useSearchParams`,
and `useRouter` to work within the `pages/` directory to aid users
attempting to migrate shared components over to the `app/` directory.
> **Exception:**
> When the pages router is not ready, `useSearchParams` will return an
empty `URLSearchParams`. This mirrors the behavior seen in the `pages/`
directory today in that `router.query` is not available until the client
hydrates.
This also adds a new option for `useRouter` to bring it line with the
correct typings with the app directory. By default, calling
`useRouter()` will return the type `NextRouter | null` to represent what
you get when you call it from a component originating from the app
directory. If you want to instead force it to return `NextRouter` as it
does today, you can pass a boolean into the `useRouter` call as such:
```ts
const router = useRouter() // typeof router === NextRouter | null
const router = useRouter(true) // typeof router === NextRouter
```
This change is designed to ease the incremental adoption of app.
Hi,
- Remove inlined CSS style which have minor performance loss. And hoist it to top of the component.
> Each time you inline an object, React re-creates a new reference to this object on every render. This causes components that receive this object to treat it as a referentially different one which have some performance pitfalls.
_Extremely sorry if I made any mistakes :(_
As the comment mentioned, React 18 with Strict Mode enabled might cause double invocation of lifecycle methods. This makes the `<RouteAnnouncer/>` being non-empty for the initial page, which is a bug (it should only announce page change whenever a navigation happens).
## Bug
- [ ] Related issues linked using `fixes #number`
- [x] Integration tests added
- [ ] Errors have helpful link attached, see `contributing.md`
## Feature
- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have helpful link attached, see `contributing.md`
## Documentation / Examples
- [ ] Make sure the linting passes by running `yarn lint`
- Use SWC to compile Next.js core server files
- Ensure only @babel/runtime/helpers/interopRequireDefault helper is used
Just an initial comparison to compare size difference of this change.
## Bug
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Errors have helpful link attached, see `contributing.md`
## Feature
- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have helpful link attached, see `contributing.md`
## Documentation / Examples
- [ ] Make sure the linting passes
# Route Announcements
## Summary
This PR improves the accessibility of NextJS's client-side navigation by announcing route changes to screen readers.
## Context
When a user who is sighted clicks on a link, they can see the content change. It's an affirmation that what the user intended to do by clicking a link actually worked! Users navigating the page via a screen-reader will not get this feedback on NextJS sites (This is an issue on many SPA-like architectures).
https://user-images.githubusercontent.com/4213649/103017382-63b02b00-44f8-11eb-9940-fb530d2d3018.mov
## Solution
Whenever there is a route change, the new `<RouteAnnouncer />` will look for a name to give the new page and then announce it! The name is found by first looking for an `h1`, falling back to `document.title`, and lastly to `pathname`. `<RouteAnnouncer />` is a visually hidden component placed within the `<AppContainer />`.
## Demo
https://user-images.githubusercontent.com/4213649/103017401-6ad73900-44f8-11eb-8050-b3e9a7e0c3f2.mov
## Inspiration
First and foremost, this PR was inspired by @marcysutton's studies and writing, [What we learned from user testing of accessible client-side routing techniques with Fable Tech Labs
](https://www.gatsbyjs.com/blog/2019-07-11-user-testing-accessible-client-routing/) as well as @madalynrose's [Accessible Routing](https://github.com/gatsbyjs/gatsby/pull/19290) PR for Gatsby.
There were also learnings gleaned from the conversations within #7681.
### Related Issues & PRs
- Resolves#7681
- Relates to #19963