serializeSignals() — astro Function Reference

Architecture documentation for the serializeSignals() function in signals.ts from the astro codebase.

Function typescript CoreAstro RoutingSystem calls 2

Entity Profile

CoreAstro→ RoutingSystem→ serializeSignals() — astro Function Reference

Dependency Diagram

graph TD
  bb4bf640_2e79_6e5f_61a3_fac209401de6["serializeSignals()"]
  4b26ab17_02c6_6dd0_7b9f_13b28a462719["signals.ts"]
  bb4bf640_2e79_6e5f_61a3_fac209401de6 -->|defined in| 4b26ab17_02c6_6dd0_7b9f_13b28a462719
  2c4af9e5_0de0_797f_0752_7f548c30f1f4["isSignal()"]
  bb4bf640_2e79_6e5f_61a3_fac209401de6 -->|calls| 2c4af9e5_0de0_797f_0752_7f548c30f1f4
  f02a9ac2_7286_bf56_c888_a5cefd08db0a["getSignalId()"]
  bb4bf640_2e79_6e5f_61a3_fac209401de6 -->|calls| f02a9ac2_7286_bf56_c888_a5cefd08db0a
  style bb4bf640_2e79_6e5f_61a3_fac209401de6 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

packages/integrations/preact/src/signals.ts lines 31–78

export function serializeSignals(
	ctx: Context,
	props: Record<string, any>,
	attrs: AstroPreactAttrs,
	map: PropNameToSignalMap,
) {
	// Check for signals
	const signals: Signals = {};
	for (const [key, value] of Object.entries(props)) {
		const isPropArray = Array.isArray(value);
		// `typeof null` is 'object' in JS, so we need to check for `null` specifically
		const isPropObject =
			!isSignal(value) && typeof props[key] === 'object' && props[key] !== null && !isPropArray;

		if (isPropObject || isPropArray) {
			const values = isPropObject ? Object.keys(props[key]) : value;
			values.forEach((valueKey: number | string, valueIndex: number) => {
				const signal = isPropObject ? props[key][valueKey] : valueKey;
				if (isSignal(signal)) {
					const keyOrIndex = isPropObject ? valueKey.toString() : valueIndex;

					props[key] = isPropObject
						? Object.assign({}, props[key], { [keyOrIndex]: signal.peek() })
						: props[key].map((v: SignalLike, i: number) =>
								i === valueIndex ? [signal.peek(), i] : v,
							);

					const currentMap = (map.get(key) || []) as SignalToKeyOrIndexMap;
					map.set(key, [...currentMap, [signal, keyOrIndex]]);

					const currentSignals = (signals[key] || []) as ArrayObjectMapping;
					signals[key] = [...currentSignals, [getSignalId(ctx, signal), keyOrIndex]];
				}
			});
		} else if (isSignal(value)) {
			// Set the value to the current signal value
			// This mutates the props on purpose, so that it will be serialized correct.
			props[key] = value.peek();
			map.set(key, value);

			signals[key] = getSignalId(ctx, value);
		}
	}

	if (Object.keys(signals).length) {
		attrs['data-preact-signals'] = JSON.stringify(signals);
	}
}