Fix ix 3104 default css classes not getting applied for dynamic tabs

[RamVinayMandal]

💡 What is the current behavior?

When tabs are added dynamically and have custom CSS classes applied, the essential default CSS classes (hydrated, bottom/top, auto/stretched, selected) are lost, causing the tabs to appear broken/unstyled. Issue persists for React and Vue.

GitHub Issue Number: #2043

Note: Older PR is closed due to major conflicts - #2082

🆕 What is the new behavior?

Dynamic CSS Class Preservation for Tab Components

Problem Fixed: When React/Vue frameworks dynamically update tab content, essential CSS classes (hydrated, selected, bottom, top, stretched) were lost, breaking tab functionality and styling.

Solution Implemented: Added a MutationObserver that automatically detects DOM changes and re-applies required system classes while preserving custom user classes, ensuring tabs remain fully functional during dynamic re-renders.

Result: Tabs now work seamlessly in React/Vue applications with dynamic content updates, maintaining both visual consistency and interactive behavior regardless of how aggressively frameworks manipulate the DOM.

🏁 Checklist

A pull request can only be merged if all of these conditions are met (where applicable):

• 🦮 Accessibility (a11y) features were implemented
• 🗺️ Internationalization (i18n) - no hard coded strings
• 📲 Responsiveness - components handle viewport changes and content overflow gracefully
• 📕 Add or update a Storybook story
• 📄 Documentation was reviewed/updated siemens/ix-docs
• 🧪 Unit tests were added/updated and pass (pnpm test)
• 📸 Visual regression tests were added/updated and pass (Guide)
• 🧐 Static code analysis passes (pnpm lint)
• 🏗️ Successful compilation (pnpm build, changes pushed)

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[gemini-code-assist]

Summary of Changes

Hello @RamVinayMandal, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request addresses an issue where dynamically added tabs in React and Vue applications were losing essential CSS classes, causing them to appear unstyled. The solution introduces a MutationObserver to monitor DOM changes and re-apply the necessary classes, ensuring tabs remain functional and visually consistent during dynamic updates. Additional regression tests have been added to validate the fix and cover various scenarios.

Highlights

• Dynamic CSS Class Preservation: Implements a MutationObserver to detect DOM changes in tab components and re-apply essential CSS classes (hydrated, selected, bottom, top, stretched) while preserving custom user classes.
• Tab Attribute Updates: Adds methods to set and apply required classes to tab items, ensuring visual consistency and interactive behavior during dynamic re-renders in frameworks like React and Vue.
• Test Cases: Adds new regression tests to verify that default classes are preserved when custom classes are added during re-renders, and to ensure correct behavior with different configurations (placement, layout, disabled state).

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[gemini-code-assist]

Code Review

This pull request effectively resolves the issue of CSS classes being lost on dynamic tab updates by introducing a MutationObserver. The approach is solid, and the new logic is well-supported by a comprehensive suite of new tests. I have one suggestion for improvement in tabs.tsx to make the class application logic more efficient and prevent potential performance issues from unnecessary DOM mutations. Overall, this is a great contribution.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud