3.1 KiB
Overlays
Dify UI overlay primitives own their Base UI portals, normal application layer, positioning, focus, modal behavior, and dismissal contracts. Consumers choose the semantic primitive and compose its exported anatomy instead of recreating those responsibilities.
Portals and root isolation
Floating surfaces render through Base UI Portal into document.body. Convenience components
such as DialogContent, PopoverContent, and SelectContent own their portals internally;
primitives with explicit anatomy expose the constituent portal and content parts.
The host must establish an isolated stacking context at its application root:
<body>
<div className="isolate h-full">{children}</div>
</body>
Equivalent CSS is isolation: isolate. It creates a stacking context so
application descendants cannot use high z-index values to compete with sibling surfaces portalled
to body. Portalling avoids clipping by application ancestors; isolation itself does not fix
clipping.
Layering
| Layer | z-index |
|---|---|
| Dialogs, pickers, drawers, menus, popovers, preview cards, and tooltips | z-50 |
| Toast viewport | z-60 |
Overlays at z-50 rely on portal DOM order; the portal mounted later appears above earlier ones.
Toast remains one layer above ordinary overlays.
- Do not add call-site
z-*overrides. Fix the owning overlay structure when content is clipped or hidden. - Do not wrap a Dify UI overlay in another manual portal.
- Add shared backdrop or presentation chrome inside the owning exported component, not at call sites.
Primitive semantics
- Use
Dialogfor modal content that needs focus containment and scroll locking. - Use
AlertDialogonly for a destructive or must-confirm decision requiring an explicit answer. - Use
Drawerfor side-panel interactions that follow the drawer model. - Use
DropdownMenufor button-triggered action lists andContextMenufor context actions. - Use
Tooltiponly for a short, non-interactive visual label. The trigger already needs an accessible name; use Popover for information users must reach on touch. - Use
PreviewCardas a non-interactive enhancement for a link destination. Essential information must also exist without the preview. - Use
Popoverfor explanatory, structured, or interactive content that users must reach on touch or with assistive technology.
Use a real <button type="button"> for button-like triggers. If a Base UI trigger intentionally
renders a non-button element, set nativeButton={false}. Let the primitive own placement and
spacing unless its API documents a measured exception.