Do not use PHP iterators in BlockMarkupProcessor – they work differently in PHP 8.0+

Author: adamziel

components/DataLiberation/BlockMarkup/BlockMarkupProcessor.php

@@ -2,8 +2,6 @@
 
 namespace WordPress\DataLiberation\BlockMarkup;
 
-use RecursiveArrayIterator;
-use RecursiveIteratorIterator;
 use WP_Block_Parser_Error;
 use WP_HTML_Tag_Processor;
 
@@ -75,11 +73,22 @@ class BlockMarkupProcessor extends WP_HTML_Tag_Processor {
 	private $last_block_error;
 
 	/**
-	 * Iterator for traversing nested block attributes
+	 * A flattened list of paths (arrays of keys) to every attribute found in
+	 * $block_attributes.  This is used by next_block_attribute() to traverse
+	 * attributes without relying on PHP iterator classes.
 	 *
-	 * @var RecursiveIteratorIterator
+	 * @var array<int, array<int|string>>|null
 	 */
-	private $block_attributes_iterator;
+	private $block_attribute_paths = null;
+
+	/**
+	 * The index of the current attribute inside $block_attribute_paths.
+	 * Starts at -1 so that the first call to next_block_attribute() positions
+	 * the cursor at index 0.
+	 *
+	 * @var int
+	 */
+	private $block_attribute_index = -1;
 
 	/**
 	 * Gets the type of the current token, adding a special '#block-comment' type
@@ -287,7 +296,8 @@ public function next_token(): bool {
 
 		$this->block_name                = null;
 		$this->block_attributes          = null;
-		$this->block_attributes_iterator = null;
+		$this->block_attribute_paths     = null;
+		$this->block_attribute_index     = -1;
 		$this->block_closer              = false;
 		$this->self_closing_flag         = false;
 		$this->block_attributes_updated  = false;
@@ -469,19 +479,19 @@ private function block_attribute_updates_to_modifiable_text_updates() {
 		if ( ! $this->block_attributes_updated ) {
 			return false;
 		}
+
 		$encoded_attributes = json_encode(
-			$this->block_attributes_iterator
-				? $this->block_attributes_iterator->getSubIterator( 0 )->getArrayCopy()
-				: $this->block_attributes,
+			$this->block_attributes,
 			JSON_HEX_TAG | // Convert < and > to \u003C and \u003E
 			JSON_HEX_AMP   // Convert & to \u0026
 		);
-		var_dump($encoded_attributes);
+
 		if ( $encoded_attributes === '[]' ) {
 			$encoded_attributes = '';
 		} else {
 			$encoded_attributes .= ' ';
 		}
+
 		$this->set_modifiable_text(
 			' ' .
 			$this->block_name .
@@ -502,28 +512,19 @@ public function next_block_attribute() {
 			return false;
 		}
 
-		if ( null === $this->block_attributes_iterator ) {
+		if ( null === $this->block_attribute_paths ) {
 			$block_attributes = $this->get_block_attributes();
 			if ( ! is_array( $block_attributes ) ) {
 				return false;
 			}
-			// Re-entrant iteration over the block attributes.
-			$this->block_attributes_iterator = new RecursiveIteratorIterator(
-				new RecursiveArrayIterator( $block_attributes ),
-				RecursiveIteratorIterator::SELF_FIRST
-			);
-		}
-
-		while ( true ) {
-			$this->block_attributes_iterator->next();
-			if ( ! $this->block_attributes_iterator->valid() ) {
-				break;
-			}
 
-			return true;
+			$this->block_attribute_paths = $this->build_block_attribute_paths( $block_attributes );
+			$this->block_attribute_index = -1;
 		}
 
-		return false;
+		$this->block_attribute_index++;
+
+		return isset( $this->block_attribute_paths[ $this->block_attribute_index ] );
 	}
 
 	/**
@@ -532,11 +533,13 @@ public function next_block_attribute() {
 	 * @return string|false The attribute key or false if no attribute was matched
 	 */
 	public function get_block_attribute_key() {
-		if ( null === $this->block_attributes_iterator || false === $this->block_attributes_iterator->valid() ) {
+		if ( null === $this->block_attribute_paths || ! isset( $this->block_attribute_paths[ $this->block_attribute_index ] ) ) {
 			return false;
 		}
 
-		return $this->block_attributes_iterator->key();
+		$path = $this->block_attribute_paths[ $this->block_attribute_index ];
+
+		return $path[ count( $path ) - 1 ];
 	}
 
 	/**
@@ -545,11 +548,21 @@ public function get_block_attribute_key() {
 	 * @return mixed|false The attribute value or false if no attribute was matched
 	 */
 	public function get_block_attribute_value() {
-		if ( null === $this->block_attributes_iterator || false === $this->block_attributes_iterator->valid() ) {
+		if ( null === $this->block_attribute_paths || ! isset( $this->block_attribute_paths[ $this->block_attribute_index ] ) ) {
 			return false;
 		}
 
-		return $this->block_attributes_iterator->current();
+		$path  = $this->block_attribute_paths[ $this->block_attribute_index ];
+		$value = $this->block_attributes;
+
+		foreach ( $path as $segment ) {
+			if ( ! is_array( $value ) || ! array_key_exists( $segment, $value ) ) {
+				return false;
+			}
+			$value = $value[ $segment ];
+		}
+
+		return $value;
 	}
 
 	/**
@@ -560,18 +573,49 @@ public function get_block_attribute_value() {
 	 * @return bool Whether the value was successfully set
 	 */
 	public function set_block_attribute_value( $new_value ) {
-		if ( null === $this->block_attributes_iterator || false === $this->block_attributes_iterator->valid() ) {
+		if ( null === $this->block_attribute_paths || ! isset( $this->block_attribute_paths[ $this->block_attribute_index ] ) ) {
 			return false;
 		}
 
-		$this->block_attributes_iterator
-			->getSubIterator( $this->block_attributes_iterator->getDepth() )
-			->offsetSet(
-				$this->get_block_attribute_key(),
-				$new_value
-			);
+		$path = $this->block_attribute_paths[ $this->block_attribute_index ];
+
+		$ref =& $this->block_attributes;
+		$depth = count( $path );
+		for ( $i = 0; $i < $depth - 1; $i ++ ) {
+			$segment = $path[ $i ];
+			if ( ! is_array( $ref ) || ! array_key_exists( $segment, $ref ) ) {
+				return false; // Path is invalid.
+			}
+			$ref =& $ref[ $segment ];
+		}
+
+		$last_key            = $path[ $depth - 1 ];
+		$ref[ $last_key ]    = $new_value;
 		$this->block_attributes_updated = true;
 
 		return true;
 	}
+
+	/**
+	 * Builds a list of attribute paths, using a depth-first, SELF_FIRST order
+	 * that matches the previous iterator behaviour.
+	 *
+	 * @param  array<int|string, mixed> $attributes
+	 * @param  array<int|string>        $base_path
+	 * @return array<int, array<int|string>>
+	 */
+	private function build_block_attribute_paths( $attributes, $base_path = array() ) {
+		$paths = array();
+
+		foreach ( $attributes as $key => $value ) {
+			$current_path   = array_merge( $base_path, array( $key ) );
+			$paths[]        = $current_path; // SELF_FIRST: include parent before children.
+
+			if ( is_array( $value ) ) {
+				$paths = array_merge( $paths, $this->build_block_attribute_paths( $value, $current_path ) );
+			}
+		}
+
+		return $paths;
+	}
 }