Add reloadOnPrerender option to reload resources in serverSideTranslations so that developers don't have to restart their server when making changes to their translation JSON files

[dcporter44]

I talked with @isaachinman at the bottom of this thread (issue #881) regarding a solution to call i18n.reloadResources() inside of serverSideTranslations. Looks like there are several issues that have been created about this topic.

I've created a new config option called reloadOnPrerender that reloads the resources in severSideTranslations. I've updated the README as well.

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[isaachinman]

I'm somewhat surprised that calling reloadResources on globalI18n works, but if so, this is quite an easy win.

We will need test coverage, though. Thanks!

[dcporter44]

@isaachinman Let me know if this test implementation seems correct. In order to test if reloadResources is called, I need to have access to the globalI18n object created by appWithTranslation. In order to do that I had to create a dummy component (like you did in appWithTranslation.test.tsx) so that globalI18n would be instantiated.

[isaachinman]

Test coverage looks fine. Just had a passing thought about the API signature to avoid unintended regressions in prod envs.

[janklimo]

If my understanding is correct, this will not enable HMR of locale files. If that's the case, I think we shouldn't have dismissed #1370 as it provides better DX.

[isaachinman]

@janklimo As I've stated numerous times, next-i18next will not support HMR, as users can easily set this up themselves via their i18next config.

This PR, however, is a one-liner and is easy to maintain.

[janklimo]

@isaachinman I see, thank you for your response. I'm just getting started with the package so I'm not aware of the previous conversations. Would you have any pointers to a resource which explains how it can be easily done using i18next config? Perhaps we could add a readme section explaining it?

[MartinCura]

Hi! Is this complete functionality? Would reeeally make DX better on the app i'm working at the moment. Is it gonna be included in a release soon?

[isaachinman]

The reloadOnPrerender option has been released in [email protected].

[MartinCura]

Thank you for the release! Saving the .json doesn't load the new strings after turning on the option but i suppose it's because modifying components and saving those files doesn't make getServerSideProps get called in my setup?

[reymons]

Thank you for the release! Saving the .json doesn't load the new strings after turning on the option but i suppose it's because modifying components and saving those files doesn't make getServerSideProps get called in my setup?

Yes. If it's gssp, you have to reload the page

[sunknudsen]

Is there a way to live update app when changes are made to translation files in locales directory?

[CommanderRedYT]

Is there a way to live update app when changes are made to translation files in locales directory?

It only works for me if the translations are JavaScript files that are exporting the translation object and using that in i18n.resources

[sunknudsen]

@CommanderRedYT Thanks for helping out!

Adding following to next-i18next.config.mjs worked for me.

import en from "./locales/en/common.json" assert { type: "json" }
import fr from "./locales/fr/common.json" assert { type: "json" }