Translated routing and more for Next using Next regular file-base routing system
- Translated paths segments
Ex:/contact-us
and/fr/contactez-nous
. - Complex paths segments (path-to-regexp synthax)
Ex:/:id{-:slug}?/
- Constrained dynamic paths segments (path-to-regexp synthax)
Ex:/:id(\\d+)/
- No duplicated content (SEO)
Simple rewrites would make a page accessible with 2 different urls which is bad for SEO. - Auto-redirection to correct translated path
Ex:/fr/english/path
redirects to/fr/french/path
- No custom server needed!
Next automatic static optimization remains available.
See it in action: https://codesandbox.io/s/github/hozana/next-translate-routes/tree/master
Note: Next-translate-routes does not work with Next html static export, since internationalized routing is among static html export unsupported features.
To build a fully internationalized website, one need to translate url segments: it is important for UX and SEO. For now, Next only ship with locale prefixes (see Next.js internationalized routing doc).
The next-routes package allow fully internationalized routing but it is no longer maintained, and it is designed without the latest Next api, such as internationalized routing, new data fetching methods, automatic static optimization.
To be able to use theses, a new approach is needed. Next.js provides it with Redirects and Rewrites, but:
- the main problem is that writing the rewrites and redirects to translate all the routes by hand is long, boring, error-prone, and hard to maintain.
- an other problem is that by default, the file path works with all the locale prefixes: it creates 2 urls for the same content, which is not good for SEO. This problem can be worked around by creating redirects from
/${localePrefix}/$(filePath)
to/${localePrefix}/$(localePath)
, but it creates a lot more complexity to write by hand and maintain.
Check the example folder to see next-translate-routes in action. Some advanced techniques are shown there too: they may seem complicated but those 4 steps should cover most of the cases.
Import the withTranslateRoutes
from next-translate-routes/plugin
.
// next.config.js
const withTranslateRoutes = require('next-translate-routes/plugin')
module.exports = withTranslateRoutes({
// Next i18n config (mandatory): https://nextjs.org/docs/advanced-features/i18n-routing
i18n: {
locales: ['en', 'fr', 'es', 'pl'],
defaultLocale: 'pl',
},
// ...Remaining next config
})
You can add a _routes.json
, or a _routes.yaml
, file in the pages
folder, and in the every subfolder where you want to define routes.
Given a folder structure like so, you can add a _routes.json
in /pages/
and in /pages/section/
.
/pages/
├ section/
| ├ page1.tsx
| ├ page2.tsx
| └ _routes.json
├ somewhere/
| └ else.json
├ _app.tsx
├ about.tsx
├ contact.tsx
└ _routes.json
In /pages/section/
, the _routes.json
file could look like this.
// `/pages/section/_routes.json`
{
"/": {
"es": "seccion" // Folder path in es
},
"page1": {
"default": "article", // Overwrite the default page path (fallback)
"es": "articulo"
},
"page2": "definition" // Overwrite the page path for all language
}
The "/": { ... }
part define the folder paths, each other section define the paths of a page file in this folder:
- page1 will be accessible at
/seccion/articulo
ines
, and at/section/article
in other languages, - page2 will be accessible at
/seccion/definition
ines
, and at/section/definition
in other languages.
You don't need a _routes.json
file in folder where you don't customize anything. If it is empty, then delete it.
Here, the /somewhere/
subfolder does not have any _routes.json
file.
Then, in /pages/
, the _routes.json
file could look like this.
// `/pages/_routes.json`
{
"/": {
"pt": "blog" // As we are in the root pages folder, this will add a "blog" path prefix for all pages in pt
},
"contact": {
"es": "contactar",
"pt": "contatar"
}
}
In the root pages folder, the "/": { ... }
part of the root _routes.json
allows to add a different basePath
for each language or only some language, like "blog" in pt
here:
- about will be accessible at
/blog/about
inpt
and at/about
in other languages, - contact will be accessible at
/blog/contatar
inpt
, at/contactar
ines
and at/contact
in other languages, - page1 will in fact be accessible at
/blog/section/article
inpt
, - page2 will in fact be accessible at
/blog/section/definition
inpt
.
// `/pages/_app.js`
import { App } from 'next/app'
import { withTranslateRoutes } from 'next-translate-routes'
export default withTranslateRoutes(App)
Or:
// `/pages/_app.js`
import { withTranslateRoutes } from 'next-translate-routes'
const App = ({ Component, pageProps }) => {
// Custom code...
return <Component {...pageProps} />
}
export default withTranslateRoutes(App)
next-translate-routes extends Next Link to translate routes automatically: import it from 'next-translate-routes/link' instead of 'next/link' and use as you ever did.
import React, { useEffect, useState } from 'react'
import Link from 'next-translate-routes/link'
const MyLinks = (props) => {
const { locales } = useRouter()
return (
<>
<Link href="/file/path/to/page">Current locale</Link>
{locales.map((locale) => (
<Link
href={{ pathname: '/file/path/to/[dynamic]/page', query: { dynamic: props.param, otherQueryParam: 'foo' } }}
locale={locale}
key={locale}
>
{locale}
</Link>
))}
</>
)
}
Check the example folder to see some advanced techniques in action.
Next-translate-routes is configurable by adding a translateRoutes
key in Next config that accept an object of the following NTRConfig
type.
type NTRConfig = {
debug?: boolean
routesDataFileName?: string
routesTree?: TRouteBranch<L>
pagesDirectory?: string
}
See more about TRouteBranch
If i18n.locales
is set to ['en', 'fr']
, then the TRouteBranch
generic L
prop would be 'en' | 'fr'
. A non-generic equivalent of TRouteBranch<'en' | 'fr'>
would be the following.
/** Non generic version of the TRouteBranch type for better readability, where the generi L prop is set to `'en' | 'fr'` */
type TRouteBranchEnFr = {
name: string
en: string
fr: string
children: TRouteBranchEnFr[]
}
translateRoutes: {
debug: true,
routesDataFileName: 'routesData',
}
When debug
is set to true, you will get some logs, both in the server terminal and in the browser console.
If routesDataFileName
is defined, to 'routesData'
for example, next-translate-routes will look in the pages
folder for files named routesData.json
or routesData.yaml
instead of the default _routes.json
or _routes.yaml
.
If routesTree
is defined, next-translate-routes won't parse the pages
folder and will use the given object as the routes tree. If you uses it, beware of building correctly the routes tree to avoid bugs.
// `/pages/blog/[id]/_routes.json`
{
"/": ":id(\\d+)", // Constrain a dynamic folder segment (to be a number here)
"[slug]": ":slug(\\w+)", // Constrain a dynamic page segment (to be letters here)
}
For a catch all route: "[...path]": ":path*"
.
This will ignore the blog
path segment:
// `/pages/blog/_routes.json`
{
"/": "."
}
It can be done for some lang only and not others.
// `/pages/blog/_routes.json`
{
"/": {
fr: "."
}
}
/!\ Ignoring a path segment can cause troubles.
Ex. Given the /a/[b]/[c] and /a/[b]/[c]/d file paths. [b] is ignored and the b param is merged with the c param: ":b-:c".
Then /a/b/c will be redirected to /a/b-c and that is fine.
But /a/b-c/d will be redirected to /a/b-c-d and that is not fine.
To handle this case, one can add a path-to-regex pattern to the default ignore token. Ex: '.(\\d+)', or '.(\[\^-\]+)'.
This path-to-regex pattern will be added after the segment name in the redirect.
Then /a/b(\d+)/c will be redirected to /a/b-c, and /a/b-c/d will not be redirected to /a/b-c-d.
/!\ This is only handled in default paths (i.e. "/": ".(\\d+)" or "/": { "default": ".(\\d+)" }), not in lang-specific paths.
// `/pages/blog/[id]/_routes.json`
{
"/": "article{-:id}?-view", // Add prefix, optional prefix, suffix
}
It is also possible to create a path segment with 2 dynamic parameters. Ex: /articles/:id{-:slug}?
.
First, create a path segment for each dynamic parameter: `/articles/[id]/[slug].
Then:
// `/articles/[id]/_routes.json`
{
"/": ".", // Ignore the [id] segment
"[slug]": ":id{-:slug}?" // Give the 2 params to the 2nd segment
}
If you want to avoid seeding _routes.json
files in your /pages
folder,
you can directly create a routesTree object, and inject it in the next config as follow.
// next.config.js
const withTranslateRoutes = require('next-translate-routes')
const getRoutesTree = require('./getRoutesTree')
const routesTree = getRoutesTree()
module.exports = withTranslateRoutes({
// Next i18n config (mandatory): https://nextjs.org/docs/advanced-features/i18n-routing
i18n: {
locales: ['en', 'fr', 'es', 'pl'],
defaultLocale: 'pl',
},
translateRoutes: {
routesTree,
},
// ...Remaining next config
})
routesTree
must be of type TRouteBranch
:
type TRouteBranch<Locale extends string> = {
name: string
paths: { default: string } & Partial<Record<Locale, string>>
children?: TRouteBranch[]
}
One might need to mock next-translate-routes outside Next, for example in Storybook. It is possible as follow:
import { RouterContext } from 'next/dist/shared/lib/router-context'
import withTranslateRoutes from 'next-translate-routes'
//[...]
const TranslateRoutes = withTranslateRoutes(
{
defaultLocale: 'fr',
debug: true,
locales: ['fr', 'en', 'es', 'pt'],
routesTree: { name: '/', paths: { default: '/' } }, // Mocked routes tree
},
({ children }) => <>{children}</>,
)
return (
<RouterContext.Provider value={Router.router}>
<TranslateRoutes pageProps={{}} router={Router.router}>
{children}
</TranslateRoutes>
</RouterContext.Provider>
)
// [...]
For Storybook, this piece of code can be used to create a decorator function.
- Next-translate-routes plugin parses the page folder and builds a routes tree object that contains the path tree and the information in the
_routes.json
files. - The plugin then uses this information to build optimized redirects and rewrites, then add them to the next config object.
- Rewrites take care of displaying the right page for the translates urls, redirects take care of the urls that would give an unwanted access to the pages (and would create duplicated content).
- The plugin adds a webpack loader for the pages/_app file. This loader adds a data object (containing the routes tree object along with other config) as first argument of the
withTranslateRoutes
high order component that wrap the app. withTranslateRoutes
makes this data available as a global variable,__NEXT_TRANSLATE_ROUTES_DATA
.- The
translateUrl
function uses this data to translate routes. - The
next-translate-routes/link
leverages thetranslateUrl
function to set theas
prop ofnext/link
to the translated url so that the link is aware of the true url destination (which is then available on hover, or on right-click - copy link for example). - The
withTranslateRoutes
enhance the router by overriding the router context, to give translation skills to the router.push (which is used on click on anext/link
), router.replace, and router.prefetch functions, using thetranslateUrl
function too.