Task: Enhance functional.component.Base with Core Configs

Summary

Enhance Neo.functional.component.Base to include support for the cls and windowId_ configurations, aligning it more closely with Neo.component.Base and enabling standard theming and multi-window support for functional components.

Rationale

For functional components to be first-class citizens within the framework, they must support fundamental features like styling via CSS classes and proper behavior in multi-window environments.

• cls: Allows developers to apply CSS classes directly to the root element of a functional component, enabling standard, stylesheet-based theming instead of relying on inline styles.
• windowId_: Is essential for the framework's multi-window capabilities. It ensures that components are correctly associated with the browser window they belong to, which is critical for event handling, rendering, and resource management.

Implementation Details

1. Add cls and windowId_ to config:

   • Introduce cls: null and windowId_: null to the static config block of FunctionalBase.
   • Ensure they are reactive.

2. Apply cls to VDOM:

   • In the onEffectRunStateChange method, after the vdom is created, merge the component's cls array with any classes already present on the root VDOM node using Neo.util.Array.union().

3. Implement afterSetWindowId:

   • Add the afterSetWindowId lifecycle hook to handle changes to the windowId_. This is necessary for managing theme files and component state when it's moved between windows.

4. Temporary Properties for Mixin Compatibility:

   • Due to a limitation where mixins do not support public class fields, the following properties, which would normally come from a mixin, had to be added directly to FunctionalBase for now:
     • childUpdateCache = {}
     • currentUpdateDepth = null
     • resolveUpdateCache = []
   • Note: This is a temporary workaround. A future task should address the root cause of the mixin limitation.

Acceptance Criteria

• cls can be configured on a functional component and is applied to its root element.
• windowId_ can be configured and its afterSet hook is correctly triggered.
• The new properties (childUpdateCache, etc.) are present on the class.
• The changes are documented and this ticket is closed.