Add locale-aware sorting

[PIG208]

For mentions auto-completion, one of the comparators we have compares user names alphabetically using String.compareTo. Ideally, we should support locale-aware sorting using realm/user language settings.

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Quoting Greg from #1165 (comment) :

Yeah, I think using an ICU library via FFI is probably the full solution. That could be something we do ourselves once FFI support is more mature, as the Flutter roadmap calls for next year. Or it looks like people are working on building such a thing for everyone (and for the full scope of ICU functionality): package:icu4x, published by "unicode.org". Still a work in progress but has Unicode engineers working with the Dart team to build the things they need to make it all work:

• Ship binaries for Dart unicode-org/icu4x#4689

(And that is indeed using FFI; here's the Dart code implementing Collator.compare.)

[vivekTiw120303]

Sir, I wanted to work on this issue, can u please assign this to me

[chrisbobbe]

Please take a look at the Zulip project's guide to getting involved with the code:

https://zulip.readthedocs.io/en/latest/contributing/contributing.html#your-first-codebase-contribution
https://zulip.readthedocs.io/en/latest/contributing/contributing.html#picking-an-issue-to-work-on

[gnprice]

@vivekTiw120303 You've now been pointed several times at our guide for picking an issue, which is also prominently linked from our README. If you're interested in contributing to Zulip, you need to spend some time reading that and then following it, including engaging with the codebase. Spamming a bunch of issue threads isn't helpful.

[AshutoshKhadse23]

Hello @PIG208 ,
At first I though of using Collator of the intl package but I noticed that Collator is not supported in dart language .

So, my approach would be using the package called diacritic

static int compareByAlphabeticalOrder(User userA, User userB, {required PerAccountStore store}) {
    final userAName = store.autocompleteViewManager.autocompleteDataCache
        .normalizedNameForUser(userA);
    final userBName = store.autocompleteViewManager.autocompleteDataCache
        .normalizedNameForUser(userB);

    final platformLocale = PlatformDispatcher.instance.locale;

    try {
      return _compareStringsWithLocale(userAName, userBName, platformLocale);
    } catch (e) {
      return userAName.compareTo(userBName);
    }
  }
  static int _compareStringsWithLocale(String a, String b, Locale locale) {
    final normalizedA = removeDiacritics(a.toLowerCase());
    final normalizedB = removeDiacritics(b.toLowerCase());

    return normalizedA.compareTo(normalizedB);
  }

After implementing the result :

[chrisbobbe]

Hi @AshutoshKhadse23; please see the issue description for how we plan to implement this.

[AshutoshKhadse23]

Hello @chrisbobbe ,
So according to the description,

My approach would be
Create a file name icu_collation.dart which will

• Loads ICU Library Dynamically – Uses DynamicLibrary.open(...) to load the ICU library (libicuuc.so, libicuuc.dylib, icuuc.dll) for locale-aware text handling.
• Uses ICU Functions for Locale-Aware Sorting – Calls ucol_open() to initialize collation, ucol_strcoll() for string comparison, and ucol_close() to clean up memory.

And then Replace compareTo() with localeAwareCompare – Ensures correct ordering of characters based on language-specific rules (e.g., accents in French, special sorting in German).

 @visibleForTesting
  static int compareByAlphabeticalOrder(User userA, User userB,
      {required PerAccountStore store}) {
    final userAName = store.autocompleteViewManager.autocompleteDataCache
        .normalizedNameForUser(userA);
    final userBName = store.autocompleteViewManager.autocompleteDataCache
        .normalizedNameForUser(userB);

    final String userLocale = Intl.systemLocale;

    return localeAwareCompare(userAName, userBName, userLocale);
  }

I approach as per my understanding on the description .