{"version":"1.0","type":"rich","title":"Extending HTMLElement as Select","description":"Four chained selection panels demonstrate a custom element hierarchy built by extending HTMLElement. The example defines `vc-select`, `vc-selectcheckbox`, `vc-xselect`, and `vc-xxselect` classes, which are registered via `customElements.define`. Each `vc-select` supports dynamic option management, state saving/restoring, and dependency-based filtering through `vc-options` and `vc-dependencies` attributes. A checkbox toggles visual state, and selection changes propagate up the element chain to toggle borders, showing event-driven composite behavior.","provider_name":"VizHub AI Studio","provider_url":"https://vizhub.com","html":"<iframe src=\"https://vizhub.com/viz/7d278160aab3492cb65d19a6c591664e?mode=embed\" width=\"960\" height=\"500\" scrolling=\"no\" frameborder=\"0\"></iframe>","width":960,"height":500,"cache_age":3600}