is_background_lazyload_enabled() ) {
return;
}
$bg_selectors = Sanitization::sanitize_background_selectors_array( $this->get_lazyload_background_selectors() );
?>
get( Constants::SETTING_LAZY_LOADING ) !== 1 ) {
return;
}
wp_enqueue_script( 'spc-lazysizes', SWCFPC_PLUGIN_URL . 'assets/js/lazysizes.min.js', [], '5.3.2' );
if ( ! $this->is_background_lazyload_enabled() ) {
return;
}
wp_register_style( 'spc_bg_lazy', false );
wp_enqueue_style( 'spc_bg_lazy' );
$lazyload_css = $this->get_background_lazy_css();
if ( empty( $lazyload_css ) ) {
remove_action( 'wp_print_scripts', [ $this, 'add_bg_lazyload_script' ] );
}
wp_add_inline_style( 'spc_bg_lazy', $lazyload_css );
}
/**
* Add style classes for lazy loading background images.
*
* @return string
*/
private function get_background_lazy_css() {
$selectors = $this->get_lazyload_background_selectors();
if ( empty( $selectors ) ) {
return '';
}
$formatted_selectors = array_map(
function ( $selector ) {
return sprintf( 'html %s:not(.%s)', $selector, self::BG_LAZYLOADED_CLASS );
},
$selectors
);
return apply_filters( 'spc_lazyload_bg_lazyload_css', strip_tags( implode( ",\n", $formatted_selectors ) . ' { background-image: none !important; }' ), $selectors );
}
/**
* Get CSS selectors for background lazy loading.
*
* @return string[]
*/
public function get_lazyload_background_selectors() {
$custom_selectors = Sanitization::sanitize_background_selectors_array(
Settings_Store::get_instance()->get( Constants::SETTING_LAZY_LOAD_BG_SELECTORS, [] )
);
return array_values(
array_unique(
array_merge(
$custom_selectors,
Constants::DEFAULT_BG_LAZYLOAD_SELECTORS,
$this->get_compatibilities_lazyload_background_selectors()
)
)
);
}
/**
* Check if background lazy loading is enabled.
*
* @return bool
*/
public function is_background_lazyload_enabled() {
return (int) Settings_Store::get_instance()->get( Constants::SETTING_LAZY_LOAD_BG ) === 1;
}
public static function get_lazyload_behaviours() {
return apply_filters(
'spc_lazyload_behaviours',
[
self::LAZY_LOAD_BEHAVIOUR_ALL => true,
self::LAZY_LOAD_BEHAVIOUR_FIXED => true,
]
);
}
/**
* Get compatibility selectors for other plugins.
*
* @return string[]
*/
private function get_compatibilities_lazyload_background_selectors() {
include_once ABSPATH . 'wp-admin/includes/plugin.php';
// Keep only the selectors for active plugins.
$active_compatibilities = array_filter( Constants::COMPAT_BG_LAZYLOAD_SELECTORS, 'is_plugin_active', ARRAY_FILTER_USE_KEY );
if ( empty( $active_compatibilities ) ) {
return [];
}
// Merge all selectors into a single array & ensure unique selectors.
// @phpstan-ignore-next-line - false positive, as array is checked above
return array_unique( array_merge( ...array_values( $active_compatibilities ) ) );
}
/**
* Check if we're on an AMP page or in the customizer.
*
* @return bool
*/
private function is_amp_or_customizer() {
return (
( function_exists( 'amp_is_request' ) && amp_is_request() ) ||
( function_exists( 'ampforwp_is_amp_endpoint' ) && ampforwp_is_amp_endpoint() ) ||
is_customize_preview()
);
}
/**
* Add user-configured external domains to the wp_resource_hints filter.
*
* Renders dns-prefetch entries as `//host` and preconnect entries as `https://host`
*
* @param array> $hints Existing resource hint entries.
* @param string $relation_type Relation type being filtered.
*
* @return array>
*/
public function add_external_domain_hints( $hints, $relation_type ) {
if ( $relation_type !== 'dns-prefetch' && $relation_type !== 'preconnect' ) {
return $hints;
}
if ( is_admin() || $this->is_amp_or_customizer() ) {
return $hints;
}
$key = $relation_type === 'dns-prefetch' ? Constants::SETTING_DNS_PREFETCH_DOMAINS : Constants::SETTING_PRECONNECT_DOMAINS;
$prefix = $relation_type === 'dns-prefetch' ? '//' : 'https://';
$raw = Settings_Store::get_instance()->get( $key );
$domains = array_filter( explode( "\n", Sanitization::sanitize_prefetch_domains( $raw ) ) );
foreach ( $domains as $host ) {
$hints[] = $prefix . $host;
}
return $hints;
}
}