WIP - Add bidirectional text support

[ahangarha]

• Resolves: RTL (Right-to-Left) text direction for some Asian languages such as Arabic, Hebrew, Persian etc. #31420

Summary

This PR is the first step towards adding bidirectional text support to the NextCloud ecosystem. It affects the entire project; accordingly, each app should have subsequent PRs.

The PR is 90+ percent complete. I decided to make the PR to

• Get early feedback to ensure it is on the right path.
• Discuss some technical challenges.

I had challenges in building the project. Generating css files and the dist directory during development is something I am uncomfortable with.

Because of supporting Samsung Internet, I needed to take some hacky approach.

Note:
We must update many components in NextCloud/vue. The most important one was the header-menu vue component which is already updated. Others will come soon. First, I need to ensure this PR is getting prepared for merge.

Screenshots

Before	After

TODO

• Decide about some classes like .right or .menu-left.
• Decide about core/css/tooltip.scss and its right|left classes
• Decide about https://github.com/nextcloud/server/blob/6b71288a30d6acbaaeb2f933a44883f3f51d7260/core/src/views/Profile.vue inline styles (for background-position.
• Add test to ensure we have proper dir attribute on the body. (help needed)

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)

[ahangarha]

@nickvergessen May you give me some feedback before I touch other files?

[ahangarha]

To make it easier to review such PRs and create a roadmap for bidirectional text support in the entire NextCloud ecosystem, I have proposed to form a kind of working group here: Working Group for Adding Bidirectional Text Support.

[ahangarha]

@joshtrichards Thanks for updating labels.

The development is blocked for now because I need some feedback. Also for the mentioned items in my todo list, I need someone with a better understanding of the ecosystem to make decision. Should I rename CSS classes? Should we keep the class names but change the behavior for now? What about tooltips?

If we make decision, I can move forward.

We need more discussion, particularly about the roadmap for apps to adapt.

If I need to contact any particular person, please let me know. Better to finish this PR sooner and start working on other parts.

[ahangarha]

Given the recent refactorings, it is hard for me to regularly rebase these changes.

I am committed to finishing this issue, not only for this PR but to add bidi support to the whole NextCloud ecosystem, but that cannot be done without some level of mutual understanding and coordination between me and the development team.

I hold on till I get some response.

Again I invite you to consider the formation of a Working Group for Adding Bidirectional Text Support.

CC: @ChristophWurst @miaulalala @nickvergessen @st3iny

[nickvergessen]

I had forwarded your PR and issue already and you should get a response soon.

There is no need to live update your PR every day/time the button is shown.

[miaulalala]

Given the recent refactorings, it is hard for me to regularly rebase these changes.

I am committed to finishing this issue, not only for this PR but to add bidi support to the whole NextCloud ecosystem, but that cannot be done without some level of mutual understanding and coordination between me and the development team.

I hold on till I get some response.

Again I invite you to consider the formation of a Working Group for Adding Bidirectional Text Support.

CC: @ChristophWurst @miaulalala @nickvergessen @st3iny

Hey, thanks for all your hard work on adding support for RTL text! We really apprechiate it!

We're currently waiting on our designers to give some feedback on this. The team leads here and in other apps have taken note, so your PRs aren't being ignored.

As for having to rebase the branch all the time, as Joas said, you don't have to. You can keep on working on your stuff and when you're done, you can manually rebase on the most current version of main then. It's not really much use resolving the conflicts now.

[ahangarha]

@miaulalala Thanks for your update.

There are cases of changing styles or structures because of refactoring. This PR should address them before considering a merge.

At this stage, I think the best thing to do is to ensure we are all on the same page.

I am looking forward to receiving updates.

[alimahwer]

I'm very interested in accomplishing the RTL and BiDi support for Nextcloud and I wish I had the required experience to help on this issue. However, I can help preview the result in the Arabic language as it is my mother's thong.

[ghorbani-ali]

@miaulalala Hi.
Is it possible to get an update on the decisions?

[alimahwer]

Any updates? Any expected deadlines for this project?

[jancborchardt]

Should I rename CSS classes? Should we keep the class names but change the behavior for now? What about tooltips?

This sounds more like a separate technical debt issue than something that is a blocker here, right @ahangarha? :) (yes they could be changed, but can be done in a follow-up)

Design-wise your pull request looks good, I think the approval needs to come from frontend/server rather.

@AndyScherzinger @sorbaugh

[AndyScherzinger]

Design-wise your pull request looks good, I think the approval needs to come from frontend/server rather.

Fine by me from what I read, like you said @jancborchardt it needs some frontend/server feedback freom @sorbaugh and team / community.

As for the questions/issues

Should I rename CSS classes? Should we keep the class names but change the behavior for now? What about tooltips?

I'd like to get some feedback from developers specifically folks developing apps, for example but not limited to @nickvergessen @ChristophWurst @st3iny @susnux @skjnldsv @juliushaertl @julien-nc @artonge

My personal, non-expert view would be to

• keep the existing one, but create new ones with the new behavior and mark the old ones deprecated via a comment.
• tooltips should be done native by now, at least in the core implementation they are to be accessible since any lib used before wasn't.

This would be the least breaking way even though non-adapting apps wouldn't support RTL then for the moment until the move to the new classes. But I think this would be the least invasive way to introduce RTL support for the platform.

Does this cover all your points @ahangarha ?

[susnux]

I agree with @AndyScherzinger

Tooltips should be done using the native title prop nowadays, for the classes I would add new one (start instead of left and end instead of right (or inline-...)). And deprecate the old ones.

[ahangarha]

Thank you all for sharing your thoughts.

I agree that we must work closely with the design and front-end team. I believe there are some complexities that require to have a clear roadmap to implement such a feature. I believe that this is needed to have a smooth transition with the minimum issues introduced to the existing users.

I already proposed the formation of a Working Group for Adding Bidirectional Text Support.

I try to be available for further discussion with the team.

[DorraJaouad]

@ahangarha

Given that I am one of nextcloud front-end developers and native arabic speaker, I would like to share my point of view on the above:

• For classes renaming, I agree as mentioned above to keep the current ones as deprecated and create new ones because some apps might rely on them thus a high chance to break things.
• As for RTL text support, I would recommend to set the RTL UI if a RTL language is selected. RTL support per text level can lead to a strange layout especially if both LTR and RTL languages are used at the same time ( like in Talk, user A writes in LTR language and user B writes in RTL language or if user status for example is set in a different language). Messages and manually-set user status are not translated to the selected language.

Indeed, there might be other challenges regarding the implementation and if you could list the ones you have found here, we are happy to discuss them.

Regarding RTL support in general, it will be a long process but doable. Using the selected language, we can modify the layout to adapt to RTL reading, like switching left-side bar to the right or icons to the right etc.. If you are looking for specific information on common styles/behavior we are following, I can help narrow down the scope to those that are relevant.

[susnux]

• I would recommend to set the RTL UI if a RLT language is selected.

Just for information: We have finally a method to figure out if RTL is used since last l10n release :)
@nextcloud/l10n: isRTL()

[ahangarha]

@DorraJaouad Thanks for your reply and it is great to have a person in the core team who understands RTL languages.

RTL support per text level can lead to a strange layout especially if both LTR and RTL languages are used at the same time ( like in Talk, user A writes in LTR language and user B writes in RTL language or if user status for example is set in a different language).

That is the whole point of me pushing for bidirectional text support rather enforcing direction globally. There are many cases I can list where we have mixed content with RTL and LTR text. One is in the chat. The other is in the apps like note where one may need to not only create a document with mixed content, but also create multiple documents, each with different language. Another case is in apps like Deck where having mixed content is inevitable. We may consider the fact that the same text might be seen by people who use different languages for their NC. The content should render in correct direction regardless of the selected language.

In all cases, the direction of each text should be correct. But I agree that sometimes for UX sake, we may enforce text alignment to be set to left or right.

But I understand your concern. And if it was that straight forward to address issues, we would have fixed this issue long time ago. This is why I need to work closely with the core and specially the design team. We need to ensure that this gets implemented properly.

We have finally a method to figure out if RTL is used since last l10n release

I think the new implementation is better because we set the global direction in the body tag. This way, only in the backend we need to make a list for RTL lanaugages, so we wont need to be worried about keeping the list in sync between FE and BE.

[nickvergessen]

Hi @ahangarha

Thanks for all the work and thoughts already. Some comments from organisational point of view:

• I invited you to our GitHub Org, so you can send the PRs from branches of our repository, so GitHub actions work properly and don't need manual approving

• We also try to coordinate reviews and we think the best way to get this in would be "component" by component, to reduce conflicts with other work taking place which breaks/conflicts the compiled assets all the time. We would assign some people that review the PRs regularly and make sure to merge them in timely fashion. Our proposal would be:

  • You send a PR touching a single app / area only
  • We assign someone to review and merge it within the next two working days
  • Once you see it's done, you can send the next chunk

  Starting with the current diff (replacing left/right on margins with inline-start/inline-end kind of things should be quick to review and can be done even without any conflict or dependency onto the actual providing RTL, (but it helps with your testing of course).

• At some point we can take care of populating the actual "this language is RTL" logic in the PHP code

• If you send me an email to <my github nickname>@nextcloud.com with an email address, I would add a guest account on our instance, so we can also align via chat and also have options for quicker/ad hoc calls and chats to discuss the approach

[ahangarha]

@nickvergessen

I totally agree with you. Your suggestion is very practical, making it very easy to move forward.

I try to plan to work on this issue very soon again.

Thanks for making it easy to work on this feature.

[liorkesos]

+1 on the need for proper RTL.
So glad this seems to be gaining momentum!