Follow-up to https://github.com/vercel/next.js/pull/17370 this adds mapping of locales to domains and handles default locales for specific domains also allowing specifying which locales can be visited for each domain.
This PR also updates to output all statically generated pages under the locale prefix to make it easier to locate/lookup and to not redirect to the default locale prefixed path when no `accept-language` header is provided.
Follow-up PR to https://github.com/vercel/next.js/pull/17370 when the path is not prefixed with a locale and the default locale is the detected locale it doesn't redirect to locale prefixed variant. If the default locale path is visited and the default locale is visited this also redirects to the root removing the un-necessary locale in the URL.
This also exposes the `defaultLocale` on the router since the RFC mentions `Setting a defaultLocale is required in every i18n library so it'd be useful for Next.js to provide it to the application.` although doesn't explicitly spec where we want to expose it. If we want to expose it differently this can be updated.
This adds the initial changes outlined in the [i18n routing RFC](https://github.com/vercel/next.js/discussions/17078). This currently treats the locale prefix on routes similar to how the basePath is treated in that the config doesn't require any changes to your pages directory and is automatically stripped/added based on the detected locale that should be used.
Currently redirecting occurs on the `/` route if a locale is detected regardless of if an optional catch-all route would match the `/` route or not we may want to investigate whether we want to disable this redirection automatically if an `/index.js` file isn't present at root of the pages directory.
TODO:
- [x] ensure locale detection/populating works in serverless mode correctly
- [x] add tests for locale handling in different modes, fallback/getStaticProps/getServerSideProps
To be continued in fall-up PRs
- [ ] add tests for revalidate, auto-export, basePath + i18n
- [ ] add mapping of domains with locales
- [ ] investigate detecting locale against non-index routes and populating the locale in a cookie
x-ref: https://github.com/vercel/next.js/issues/17110
Removes `next-head-count`, improving support for 3rd party libraries that insert or append new elements to `<head>`.
---
This is more or less what a solution with a `data-` attribute would look like, except that instead of directly searching for elements with that attribute, we serialize the elements expected in `<head>` and then find them/assume ownership of them during initialization (in a manner similar to React's reconciliation) based on their properties.
There are two main assumptions here:
1. Content is served with compression, so duplicate serialization of e.g. inline script or style tags doesn't have a meaningful impact. Storing a hash would be a potential optimization.
2. 3rd party libraries primarily only insert new, unique elements to head. Libraries trying to actively manage elements that overlap with those that Next.js claims ownership of will still be unsupported.
The reason for this roundabout approach is that I'd really like to avoid `data-` if possible, for maximum compatibility. Implicitly adding an attribute could be a breaking change for some class of tools or crawlers and makes it otherwise impossible to insert raw HTML into `<head>`. Adding an unexpected attribute is why the original `class="next-head"` approach was problematic in the first place!
That said, while I don't expect this to be more problematic than `next-head-count` (anything that would break in this new model also should have broken in the old model), if that does end up being the case, it might make sense to just bite the bullet.
Fixes#11012Closes#16707
---
cc @Timer @timneutkens
This pull request replaces our client-side style transitions with `<style>` tags over async `<link rel=stylesheet>` tags. This should fix some edge cases users see with Chrome accidentally causing a FOUC.
This also removes the need to perform an async operation before starting the render, which should remove any perceivable navigation delay.
---
Fixes#16289
This pull request reuses existing `<link rel=stylesheet>` tags if their `href` matches instead of recreating it. This is in effort to fix an edge case where the browser will FOUC on the tag swap.
This behavior should be sufficiently covered by all the existing CSS cases, as misbehavior would result in the resulting CSS styles being incorrect.
This pull request correctly tracks render cancelation behavior. Prior to this PR, we'd have an unhandled rejection that left the app in a bad state and no routeChangeError event was fired.
---
Closes#16424Fixes#16445
This fixes an edge case where every dozen or so transitions you'll see a flash depending on what's happening on the main thread at the time.
I'm not sure it's possible to test for this case, so we'll just have to do more field testing with this.
This pull request adds a test case for the reproduction provided in #12445. This bug is specifically caused when loading the next page before navigation has actually occurred.
---
Fixes#12445
