Node Attribute Adjustments (#16)

- Switch to correct Attribute retrieval function
- Ensure mapped classes are unique, remove empties, and trim the class string
- Add flag to control whether to keep original classes in standard block mappings

src/Blocks/Model/FlowElementTransform.php

@@ -97,9 +97,7 @@ abstract public function supportedTagName(): string;
 	 */
 	public function verifyClassAttribute( Crawler $_element, array $_expectedClasses ): bool {
 		// Manually split and match instead of HtmlPageCrawler hasClass(), which can only handle one class at a time
-		$attribute = $_element->matches( '*' ) && method_exists( $_element, 'getAttribute' )
-			? $_element->getAttribute( 'class' )
-			: null;
+		$attribute = $_element->matches( '*' ) ? $_element->attr( 'class' ) : null;
 		$classes   = preg_split( '/\s+/', $attribute ?? '' );
 		$checkSet  = false !== $classes ? Arrays::from( $classes ) : Arrays::fresh();
 

src/Blocks/Model/StandardBlock.php

@@ -69,6 +69,14 @@ protected function filterNodeAndAttributes(
 		Arrays $_domAttributes
 	): void {}
 
+	/**
+	 * Flag whether to keep the original set of Node classes when mapping
+	 *  - Override as false in a consuming class to remove the original class listing
+	 */
+	protected function keepOriginalMappedClasses(): bool {
+		return true;
+	}
+
 
 	/**
 	 * Check the nodes class list and replace select classes
@@ -81,15 +89,21 @@ protected function mapClasses( Crawler $_node ): string {
 		$classes     = Arrays::fresh();
 		$nodeClasses = $_node->attr( 'class' ) ?? '';
 
-		$classes->addMaybe( $nodeClasses, ! empty( $nodeClasses ) );
+		$classes->addMaybe( $nodeClasses, $this->keepOriginalMappedClasses() && ! empty( $nodeClasses ) );
 
 		foreach ( $this->classMapping() as $original => $replacement ) {
 			$nodeHasOriginal = $this->verifyClassAttribute( $_node, [ $original ] );
 
 			$classes->addMaybe( $replacement, $nodeHasOriginal );
 		}
 
-		return $classes->join( ' ' );
+		return trim(
+			$classes->filterUnique()->filter(
+				function ( $_item ) {
+					return ! empty( $_item );
+				}
+			)->join( ' ' )
+		);
 	}
 
 	/**