@blossom-carousel/svelte/dist/ssrSlideCount.js

A native-scroll-first carousel component for Svelte.

import { getAllContexts } from "svelte";
import { render } from "svelte/server";
import SlideProbe from "./SlideProbe.svelte";
import { countSlideMarkers } from "./countSlideMarkers.js";
import { setSlideCount } from "./slideRegistry.js";
/**
 * Server-only: unlike a Vue vnode tree or a React element tree, a Svelte
 * snippet is an opaque render function, not an introspectable data
 * structure. So slide count is derived by rendering the carousel's
 * `children` snippet through a tiny probe component and counting
 * `data-blossom-slide` occurrences in the resulting HTML string.
 *
 * Guarded to run only during SSR — on the client this is a no-op, since
 * dots seed their initial count directly from the live (already-hydrated)
 * DOM instead (see `navigation.ts`). Browser bundles don't even include
 * this module: the `browser` field in package.json swaps it for
 * `ssrSlideCount.client.ts`, keeping `svelte/server` out of client builds.
 */
export function registerSlideCountFromSnippet(id, children) {
    if (typeof document !== "undefined" || !children)
        return;
    // Forward the carousel's contexts, so slide components that call
    // `getContext` see the same values in the probe render as in the real
    // render. (Like the caller, this runs during component construction, so
    // reading the current context here is legal.)
    const context = getAllContexts();
    try {
        const { body } = render(SlideProbe, { props: { children }, context });
        setSlideCount(id, countSlideMarkers(body));
    }
    catch (error) {
        // Most likely async SSR (`experimental.async`) with `await` inside the
        // children snippet, which a synchronous probe render cannot handle.
        // Leave the count unseeded (dots render empty until hydration) instead
        // of failing the whole request.
        console.warn(`[blossom-carousel] Could not server-render the children of carousel "${id}" ` +
            `to count its slides; dots will seed on the client instead.`, error);
    }
}