wp_img_tag_add_loading_optimization_attrs( string   $image , string   $context  ): string

Source

 function wp_img_tag_add_loading_optimization_attrs( $image, $context ) { $width             = preg_match( '/ width=["\']([0-9]+)["\']/', $image, $match_width ) ?  (int) $match_width[1] : null; $height            = preg_match( '/ height=["\']([0-9]+)["\']/', $image, $match_height ) ?  (int) $match_height[1] : null; $loading_val       = preg_match( '/ loading=["\']([A-Za-z]+)["\']/', $image, $match_loading ) ? $ match_loading[1] : null; $fetchpriority_val = preg_match( '/ fetchpriority=["\']([A-Za-z]+)["\']/', $image, $match_fetchpriority ) ? $ match_fetchpriority[1] : null; $decoding_val      = preg_match( '/ decoding=["\']([A-Za-z]+)["\']/', $image, $match_decoding ) ? $ match_decoding[1] : null; /* * Get loading optimization attributes to use. * This must occur before the conditional check below so that even images * that are ineligible for being lazy-loaded are considered. */ $optimization_attrs = wp_get_loading_optimization_attributes( 'img', array( 'width'         => $width, 'height'        => $height, 'loading'       => $loading_val, 'fetchpriority' => $fetchpriority_val, 'decoding'      => $decoding_val, ), $context ); // Images should have source for the loading optimization attributes to be added. if ( !  str_contains( $image, ' src="' ) ) { return $image; } if ( empty( $decoding_val ) ) { /** * Filters the `decoding` attribute value to add to an image.  Default `async`. * * Returning a falsey value will omit the attribute. * * @since 6.1.0 * * @param string|false|null $value       The `decoding` attribute value. Returning a falsey value *                                       will result in the attribute being omitted for the image. *                                       Otherwise, it may be: 'async', 'sync', or 'auto'. Defaults to false. * @param string            $image       The HTML `img` tag to be filtered. * @param string            $context     Additional context about how the function was called *                                       or where the img tag is. */ $filtered_decoding_attr = apply_filters( 'wp_img_tag_add_decoding_attr', isset( $optimization_attrs['decoding'] ) ? $ optimization_attrs['decoding'] : false, $image, $context ); // Validate the values after filtering. if ( isset( $optimization_attrs['decoding'] ) && ! $ filtered_decoding_attr ) { // Unset `decoding` attribute if `$filtered_decoding_attr` is set to `false`. unset( $optimization_attrs['decoding'] ); } elseif ( in_array( $filtered_decoding_attr, array( 'async', 'sync', 'auto' ), true ) ) { $optimization_attrs['decoding'] = $filtered_decoding_attr; } if ( !  empty( $optimization_attrs['decoding'] ) ) { $image = str_replace( '<img', '<img decoding="' . esc_attr( $optimization_attrs['decoding'] ) . '"', $image ); } } // Images should have dimension attributes for the 'loading' and 'fetchpriority' attributes to be added. if ( !  str_contains( $image, ' width="' ) || ! str_contains( $image, ' height="' ) ) { return $image; } // Retained for backward compatibility. $loading_attrs_enabled = wp_lazy_loading_enabled( 'img', $context ); if ( empty( $loading_val ) && $loading_attrs_enabled ) { /** * Filters the `loading` attribute value to add to an image.  Default `lazy`. * * Returning `false` or an empty string will not add the attribute. * Returning `true` will add the default value. * * @since 5.5.0 * * @param string|bool $value    The `loading` attribute value. Returning a falsey value will result in *                              the attribute being omitted for the image. * @param string      $image    The HTML `img` tag to be filtered. * @param string      $context Additional context about how the function was called or where the img tag is. */ $filtered_loading_attr = apply_filters( 'wp_img_tag_add_loading_attr', isset( $optimization_attrs['loading'] ) ? $ optimization_attrs['loading'] : false, $image, $context ); // Validate the values after filtering. if ( isset( $optimization_attrs['loading'] ) && ! $ filtered_loading_attr ) { // Unset `loading` attributes if `$filtered_loading_attr` is set to `false`. unset( $optimization_attrs['loading'] ); } elseif ( in_array( $filtered_loading_attr, array( 'lazy', 'eager' ), true ) ) { /* * If the filter changed the loading attribute to "lazy" when a fetchpriority attribute * with value "high" is already present,  trigger a warning since those two attribute * values should be mutually exclusive. * * The same warning is present in `wp_get_loading_optimization_attributes()`, and here it * is only intended for the specific scenario where the above filtered caused the problem. */ if ( isset( $optimization_attrs['fetchpriority'] ) && 'high' === $optimization_attrs['fetchpriority'] && ( isset( $optimization_attrs['loading'] ) ? $ optimization_attrs['loading'] : false ) !== $ filtered_loading_attr && 'lazy' === $filtered_loading_attr ) { _doing_it_wrong( __FUNCTION__, __( 'An image should not be lazy-loaded and marked as high priority at the same time.' ), '6.3.0' ); } // The filtered value will still be respected. $optimization_attrs['loading'] = $filtered_loading_attr; } if ( !  empty( $optimization_attrs['loading'] ) ) { $image = str_replace( '<img', '<img loading="' . esc_attr( $optimization_attrs['loading'] ) . '"', $image ); } } if ( empty( $fetchpriority_val ) && !  empty( $optimization_attrs['fetchpriority'] ) ) { $image = str_replace( '<img', '<img fetchpriority="' . esc_attr( $optimization_attrs['fetchpriority'] ) . '"', $image ); } return $image; }

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