Update to fix CCP locale switching

[cocomarine]

Changes

Locale switching fix

• Before: caching wasn't working properly, hence the editor-standalone not behaving consistently and the CCP broken with locale switching (see https://www.figma.com/board/21lOTDiDkQ0cdUNF2fpnZh/Editor-behaviour-on-locale-change?node-id=0-1&p=f&t=osxIb33Az8NX4iqL-0)
• Added a locale match check before loading a cached project in useProject hook
  • This is a temporary fix as it effectively disabled caching.
  • Both editor-standalone and projects-ui behave in the same way after this change.

Initial load problem fix

• Before: when an editor page with locales other than en was first loaded in CCP, it rendered en page rather than the locale page (editor-standalone was fine)
• Updated to make sure initial attributes like locale are passed to React by reading them from the DOM in reactProps() of web-component.js
  • This is so that the first render uses the host's value even when attributeChangedCallback hasn't been run yet

[Copilot]

Pull request overview

This PR updates the project-loading hook to make localStorage cache usage dependent on the active i18n locale, aiming to prevent incorrect cached content from being loaded after CCP locale switching.

Changes:

• Adds a locale match check (cachedProject?._cachedLocale === i18n.language) before loading a cached project.
• Simplifies the cache eligibility logic into a single shouldUseCache condition.

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[zetter-rpf]

Looking at examples of other custom components (such as the one here ) it looks like a common pattern is to use hasAttribute. The benefit of using this is we might be able to remove the (raw != null) check here and also the new if (rawValue == null || rawValue === "") return rawValue; check in parseAttribute (since there could be a reasons you might want to set an attribute to ""?). For example:

 if (this.hasAttribute(name)) {
   const raw = this.getAttribute(name);
   fromDom[camelCase(name)] = this.parseAttribute(name, raw);
}

[zetter-rpf]

This is a temporary fix as it effectively disabled caching.

For my understanding, do you mean this disables the project caching when you change locale? Or is it more than that?

[zetter-rpf]

Thanks for the fix, the approach looks good. Let me know when you have fixed the tests and I can re-review.

It would be good to have at least one new test for the updated behaviour of useProject