Gallery: update the get_post_galleries method to account for gallery blocks

src/wp-includes/media.php

@@ -4711,7 +4711,7 @@ function get_post_galleries( $post, $html = true ) {
 		return array();
 	}
 
-	if ( ! has_shortcode( $post->post_content, 'gallery' ) ) {
+	if ( ! has_shortcode( $post->post_content, 'gallery' ) && ! has_block( 'gallery', $post->post_content ) ) {
 		return array();
 	}
 
@@ -4753,6 +4753,76 @@ function get_post_galleries( $post, $html = true ) {
 		}
 	}
 
+	if ( has_block( 'gallery', $post->post_content ) ) {
+		$post_blocks = parse_blocks( $post->post_content );
+		// Use while/array_shift instead of foreach so we can modify the array from within the loop
+		while ( $block = array_shift( $post_blocks ) ) {
+			if ( 'core/gallery' === $block['blockName'] ) {
+				// If a Gallery block has innerBlocks it is the new format and needs to be handled separately to the old
+				// format with nested <img> tags.
+				if ( ! empty( $block['innerBlocks'] ) ) {
+					$gallery_srcs = array();
+					$ids          = array();
+					$block_html   = array();
+					foreach ( $block['innerBlocks'] as $image ) {
+						if ( $html ) {
+							$block_html[] = $image['innerHTML'];
+						} else {
+							$gallery_srcs[] = wp_get_attachment_url( $image ['attrs']['id'] );
+							$ids[]          = $image['attrs']['id'];
+						}
+					}
+					if ( $html ) {
+						$galleries[] = '<figure>' . implode( ' ', $block_html ) . '</figure>';
+					} else {
+						$galleries[] = array(
+							// array_filter will eliminate any empty entries that came from unknown or invalid IDs
+							'src' => array_values( array_filter( array_unique( $gallery_srcs ) ) ),
+							// Only explicitly include the ids attribute. In future this could be changed to include all attributes, similar to $shortcode_attrs above.
+							'ids' => implode( ',', $ids ),
+						);
+					}
+				} else {
+					// Now handle the v1 gallery block format.
+					if ( $html ) {
+						$galleries[] = $block['innerHTML'];
+					} elseif ( ! empty( $block['attrs']['ids'] ) ) {
+						// Use the image IDs from the json blob as canonical if present
+						$gallery_srcs = array();
+						foreach ( $block['attrs']['ids'] as $gallery_img_id ) {
+							$gallery_srcs[] = wp_get_attachment_url( $gallery_img_id );
+						}
+						$galleries[] = array(
+							// array_filter will eliminate any empty entries that came from unknown or invalid IDs
+							'src' => array_values( array_filter( array_unique( $gallery_srcs ) ) ),
+							// Only explicitly include the ids attribute. In future this could be changed to include all attributes, similar to $shortcode_attrs above.
+							'ids' => implode( ',', $block['attrs']['ids'] ),
+						);
+					} else {
+						// Otherwise extract srcs from the innerHTML
+						$srcs = array();
+						preg_match_all( '#src=([\'"])(.+?)\1#is', $block['innerHTML'], $src, PREG_SET_ORDER );
+						if ( ! empty( $src ) ) {
+							foreach ( $src as $s ) {
+								$srcs[] = $s[2];
+							}
+						}
+
+						$galleries[] = array(
+							// Note that unlike shortcodes, all we are returning here is the src list
+							'src' => array_values( array_unique( $srcs ) ),
+						);
+					}
+				}
+			} elseif ( ! empty( $block['innerBlocks'] ) ) {
+				// If we have nested blocks then gradually flatten it by moving those onto the end of the root array for traversal
+				while ( $inner = array_pop( $block['innerBlocks'] ) ) {
+					array_push( $post_blocks, $inner );
+				}
+			}
+		}
+	}
+
 	/**
 	 * Filters the list of all found galleries in the given post.
 	 *