Site locale syntax does not work with Jekyll 4

[quantrung9]

Environment

• Minimal Mistakes version: 4.20.2 (latest)
• Ruby gem version: ruby 2.7.1p83 (2020-03-31 revision a0c7c23c9c)
• Jekyll version: 4.1.1
• Git repository URL: https://github.com/toolownerforked/minimal-mistakes-on-jekyll-4
• Operating system: Ubuntu 20.04

Expected behavior

When I set the locale to another language, such as France, it does not display France as expected, still in English, even I stopped and started the Jekyll server again.

I dug into the template a little bit and find out that this syntax:

{{ site.data.ui-text[site.locale].recent_posts | inspect }}

will return nill, instead of a locale string.

Steps to reproduce the behavior

install minimal-mistakes on Jekyll 4 (starting from jekyll new command), then set locale to France like this: toolownerforked/minimal-mistakes-on-jekyll-4@92596e7

[iBug]

Check the docs:

From v4.5.0 onwards, the default language files are read-in automatically via the jekyll-data plugin if it's installed. For sites hosted with GitHub Pages, you still need to copy the _data/ui-text.yml file because the jekyll-data plugin is unsupported on GitHub Pages.

[quantrung9]

Thanks, @iBug, in my repo, I did not keep any copy of data files. When I mentioned the syntax and the template, I just want to show the issue behind that.

[mmistakes]

At some point I removed the jekyll-data plugin as a dependency. I had a reason but don't remember what it was.
But when it was removed that statement above was left in and probably should have been removed too as I don't think bundled _data files carry over into sites using the theme.

I could be wrong on that as I haven't tested. I seem to remember Jekyll core adding this as a feature and that could be why I removed the plugin, or not.

[iBug]

@quanengineering Sorry I didn't notice I copied the text from an older revision of the repository (possibly forgot to git pull or such). I've updated it to match the current version in the live documentation site.

To be clear: It's now recommended that you copy _data/ui-text.yml into your repository for the localization feature to work.

[quantrung9]

Thanks @iBug, and @mmistakes.