Block Supports: Ensure consistent output in different PHP versions (#…

…25240) Get DOM root and extract substring contents In some versions of PHP (< 7.3) the `DOMDocument::saveHtml( $node )` method would format HTML introducing whitespace that could result in different rendered results in the browser. Avoid using the `DOMDocument::saveHtml( $node )` to ensure consistent behavior with supported PHP versions. Mentioned here: #25028 (comment)
WordPress · Sep 11, 2020 · 6671cef · 6671cef
1 parent 5dc434c
commit 6671cef
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Showing 2 changed files with 23 additions and 6 deletions.
diff --git a/lib/block-supports/index.php b/lib/block-supports/index.php
@@ -104,12 +104,15 @@ function gutenberg_apply_block_supports( $block_content, $block ) {
 		$block_root->setAttribute( 'style', implode( '; ', $new_styles ) . ';' );
 	}
 
-	$result = '';
-	// phpcs:ignore WordPress.NamingConventions.ValidVariableName.UsedPropertyNotSnakeCase
-	foreach ( $body_element->childNodes as $child_node ) {
-		$result .= $dom->saveHtml( $child_node );
-	}
-	return $result;
+	// Avoid using `$dom->saveHtml( $node )` because the node results may not produce consistent
+	// whitespace for PHP < 7.3. Saving the root HTML `$dom->saveHtml()` prevents this behavior.
+	$full_html = $dom->saveHtml();
+
+	// Find the <body> open/close tags. The open tag needs to be adjusted so we get inside the tag
+	// and not the tag itself.
+	$start = strpos( $full_html, '<body>', 0 ) + strlen( '<body>' );
+	$end   = strpos( $full_html, '</body>', $start );
+	return trim( substr( $full_html, $start, $end - $start ) );
 }
 add_filter( 'render_block', 'gutenberg_apply_block_supports', 10, 2 );
 

diff --git a/phpunit/class-block-supported-styles-test.php b/phpunit/class-block-supported-styles-test.php
@@ -880,6 +880,20 @@ public function test_render_block_includes_appended_html() {
 		$this->assertEquals( '<p class="wp-block-example">Hello from the block content!</p><div>Appended</div>', $result );
 	}
 
+	/**
+	 * Ensure that HTML is correctly extracted with multibyte contents.
+	 */
+	public function test_render_block_mb_html() {
+		$this->register_block_type(
+			'core/example',
+			array( 'render_callback' => true )
+		);
+
+		$result = do_blocks( '<!-- wp:core/example --><ul><li>🙂</li><li>😕</li><li>😵</li><li>😎</li></ul><!-- /wp:core/example -->' );
+
+		$this->assertEquals( '<ul class="wp-block-example"><li>🙂</li><li>😕</li><li>😵</li><li>😎</li></ul>', $result );
+	}
+
 	/**
 	 * Should not error when the rendered block is text only.
 	 */