elMatchesStrategy() — astro Function Reference

Architecture documentation for the elMatchesStrategy() function in index.ts from the astro codebase.

Function typescript CoreAstro RenderingEngine calls 1 called by 4

Entity Profile

CoreAstro→ RenderingEngine→ elMatchesStrategy() — astro Function Reference

Dependency Diagram

graph TD
  70bfc884_b3b0_e84b_4b73_06d369aade2b["elMatchesStrategy()"]
  315e53ea_6d34_137c_ce5c_8c89aca90db9["index.ts"]
  70bfc884_b3b0_e84b_4b73_06d369aade2b -->|defined in| 315e53ea_6d34_137c_ce5c_8c89aca90db9
  24714cbf_c269_c51b_a951_fe6138916c1c["initTapStrategy()"]
  24714cbf_c269_c51b_a951_fe6138916c1c -->|calls| 70bfc884_b3b0_e84b_4b73_06d369aade2b
  90b6d96b_d7f2_cf1e_695c_fcf15d5c6440["initHoverStrategy()"]
  90b6d96b_d7f2_cf1e_695c_fcf15d5c6440 -->|calls| 70bfc884_b3b0_e84b_4b73_06d369aade2b
  8c99d8e4_b1d5_84e4_ba47_c797c9e87ba9["initViewportStrategy()"]
  8c99d8e4_b1d5_84e4_ba47_c797c9e87ba9 -->|calls| 70bfc884_b3b0_e84b_4b73_06d369aade2b
  f350ee51_b3bd_e845_7222_24e2d4d0756a["initLoadStrategy()"]
  f350ee51_b3bd_e845_7222_24e2d4d0756a -->|calls| 70bfc884_b3b0_e84b_4b73_06d369aade2b
  fa17c239_9e46_24a4_170f_6c1482c21778["isSlowConnection()"]
  70bfc884_b3b0_e84b_4b73_06d369aade2b -->|calls| fa17c239_9e46_24a4_170f_6c1482c21778
  style 70bfc884_b3b0_e84b_4b73_06d369aade2b fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

packages/astro/src/prefetch/index.ts lines 267–293

function elMatchesStrategy(el: EventTarget | null, strategy: string): el is HTMLAnchorElement {
	// @ts-expect-error access unknown property this way as it's more performant
	if (el?.tagName !== 'A') return false;
	const attrValue = (el as HTMLElement).dataset.astroPrefetch;

	// Out-out if `prefetchAll` is enabled
	if (attrValue === 'false') {
		return false;
	}

	// Fallback to tap strategy if using data saver mode or slow connection
	if (strategy === 'tap' && (attrValue != null || prefetchAll) && isSlowConnection()) {
		return true;
	}

	// If anchor has no dataset but we want to prefetch all, or has dataset but no value,
	// check against fallback default strategy
	if ((attrValue == null && prefetchAll) || attrValue === '') {
		return strategy === defaultStrategy;
	}
	// Else if dataset is explicitly defined, check against it
	if (attrValue === strategy) {
		return true;
	}
	// Else, no match
	return false;
}