Filter hook 'wp_min_priority_img_pixels'

Description

Filters the header-specific contexts.

Occurrences

Parameters

PHP Doc

/**
		 * Filters the header-specific contexts.
		 *
		 * @since 6.4.0
		 *
		 * @param array $default_header_enforced_contexts Map of contexts for which elements should be considered
		 *                                                in the header of the page, as $context => $enabled
		 *                                                pairs. The $enabled should always be true.
		 */
		$header_enforced_contexts = apply_filters( 'wp_loading_optimization_force_header_contexts', $header_enforced_contexts );

		// Consider elements with these header-specific contexts to be in viewport.
		if ( isset( $header_enforced_contexts[ $context ] ) ) {
			$maybe_in_viewport    = true;
			$maybe_increase_count = true;
		} elseif ( ! is_admin() && in_the_loop() && is_main_query() ) {
			/*
			 * Get the content media count, since this is a main query
			 * content element. This is accomplished by "increasing"
			 * the count by zero, as the only way to get the count is
			 * to call this function.
			 * The actual count increase happens further below, based
			 * on the `$increase_count` flag set here.
			 */
			$content_media_count = wp_increase_content_media_count( 0 );
			$increase_count      = true;

			// If the count so far is below the threshold, `loading` attribute is omitted.
			if ( $content_media_count < wp_omit_loading_attr_threshold() ) {
				$maybe_in_viewport = true;
			} else {
				$maybe_in_viewport = false;
			}
		} elseif (
			// Only apply for main query but before the loop.
			$wp_query->before_loop && $wp_query->is_main_query()
			/*
			 * Any image before the loop, but after the header has started should not be lazy-loaded,
			 * except when the footer has already started which can happen when the current template
			 * does not include any loop.
			 */
			&& did_action( 'get_header' ) && ! did_action( 'get_footer' )
			) {
			$maybe_in_viewport    = true;
			$maybe_increase_count = true;
		}
	}

	/*
	 * If the element is in the viewport (`true`), potentially add
	 * `fetchpriority` with a value of "high". Otherwise, i.e. if the element
	 * is not not in the viewport (`false`) or it is unknown (`null`), add
	 * `loading` with a value of "lazy".
	 */
	if ( $maybe_in_viewport ) {
		$loading_attrs = wp_maybe_add_fetchpriority_high_attr( $loading_attrs, $tag_name, $attr );
	} else {
		// Only add `loading="lazy"` if the feature is enabled.
		if ( wp_lazy_loading_enabled( $tag_name, $context ) ) {
			$loading_attrs['loading'] = 'lazy';
		}
	}

	/*
	 * If flag was set based on contextual logic above, increase the content
	 * media count, either unconditionally, or based on whether the image size
	 * is larger than the threshold.
	 */