Alert
A box that says something happened — and the first component here with no script at all.
src/components/rahti_ui/alert.rs
The box
An icon, a title and a description — three children and no props.
shadcn's own demo, with this library's icon set standing in for its lucide names. The icon is a child rather than a prop, and nothing tells the box it is there — `has-[>svg]:grid-cols-[auto_1fr]` notices.
The icon needs nothing said about it either. `*:[svg:not([class*='size-'])]:size-4` sizes it, `*:[svg]:text-current` makes it take the box's colour, and `*:[svg]:row-span-2` is what lets it sit beside both lines rather than beside only the title.
Destructive
The one variant shadcn ships, and what it actually changes.
shadcn's destructive alert is not a red box — it is a box with red text. The background stays `bg-card` and only the writing changes, which is why the variant is two utilities and a third that reaches into the description: `*:data-[slot=alert-description]:text-destructive/90`.
The icon follows without being told, because `*:[svg]:text-current` was already in the base string. Change the box's text colour and the icon comes with it.
With an action
A button in the corner, and the padding that makes room for it.
The button is pinned with `absolute top-2 right-2` — but that is only half of it. The other half is on the root: `has-data-[slot=alert-action]:pr-18` reserves the room, so the text stops before the button rather than running underneath it. A box with no action pays no right padding at all.
That is also why `AlertAction`'s `data-slot` is load-bearing rather than decorative — the root finds it by that name, and renaming it gives you a button sitting on top of the text.
`AlertAction` is the part the published `new-york-v4` registry does not have. See the last section for why this port follows the docs page instead.
What it does with what it is given
The same component four times, rearranging itself from its children.
A description can hold more than a sentence.
Every paragraph but the last gets its own spacing, which is `[&_p:not(:last-child)]:mb-4` and needs nothing said about it.
Four boxes, one component, no props between them. The grid grows a column when an icon turns up and loses it again when one does not; the title reads the root's `group/alert` to decide which column it belongs in, because a child cannot see its own siblings but it can see a named ancestor.
The third box has no description at all and does not need one — the rows are implicit, so there is nothing to leave empty.
Colours
A different tone without a variant.
shadcn's colours demo, and it is a `class` on the root and nothing else — no variant, no new part. The description keeps its muted colour and the icon takes the amber, because `*:[svg]:text-current` follows whatever the box's text colour turns out to be.
This is the one place the component pays for a caller's `class`: an override is the only thing that can conflict with what the component chose, so the class list becomes `{twMerge(…)}` and is resolved in the browser. Without an override it is a finished string from the server.
The port
Where these strings came from, and why not the usual place.
Every other component in this library takes its class strings from the published registry, and this one does not. The reason is narrow and worth stating: for `alert` the registry is stale, and a port built from it would look wrong next to the page it was copied from. The strings here are the docs page's, exactly, and they are plain utilities rather than the `cn-*` markers the Base UI style uses — so nothing is lost by reading them there.
`role="alert"` is shadcn's and it is worth knowing what it means: a screen reader announces this box the moment it appears. It is for something that just happened, not for a note that was always on the page.