#110 remove redundant Element class methods and code refactoring

README.md

@@ -412,12 +412,12 @@ Example using ast
 
 ```php
 
-use TBela\CSS\Ast\Traverser;
+use TBela\CSS\Ast\NodeWalker;
 use TBela\CSS\Parser;
 use TBela\CSS\Renderer;
 
 $parser = (new Parser())->load('ast/media.css');
-$traverser = new Traverser();
+$traverser = new NodeWalker();
 $renderer = new Renderer(['remove_empty_nodes' => true]);
 
 $ast = $parser->getAst();
@@ -427,7 +427,7 @@ $traverser->on('enter', function ($node) {
 
     if ($node->type == 'AtRule' && $node->name == 'media' && $node->value == 'print') {
 
-        return Traverser::IGNORE_NODE;
+        return NodeWalker::IGNORE_NODE;
     }
 });
 
@@ -439,12 +439,12 @@ Example using an Element instance
 
 ```php
 
-use TBela\CSS\Ast\Traverser;
+use TBela\CSS\Ast\NodeWalker;
 use TBela\CSS\Parser;
 use TBela\CSS\Renderer;
 
 $parser = (new Parser())->load('ast/media.css');
-$traverser = new Traverser();
+$traverser = new NodeWalker();
 $renderer = new Renderer(['remove_empty_nodes' => true]);
 
 $element = $parser->parse();
@@ -454,7 +454,7 @@ $traverser->on('enter', function ($node) {
 
     if ($node->type == 'AtRule' && $node->name == 'media' && $node->value == 'print') {
 
-        return Traverser::IGNORE_NODE;
+        return NodeWalker::IGNORE_NODE;
     }
 });
 

docs/README.md

@@ -412,12 +412,12 @@ Example using ast
 
 ```php
 
-use TBela\CSS\Ast\Traverser;
+use TBela\CSS\Ast\NodeWalker;
 use TBela\CSS\Parser;
 use TBela\CSS\Renderer;
 
 $parser = (new Parser())->load('ast/media.css');
-$traverser = new Traverser();
+$traverser = new NodeWalker();
 $renderer = new Renderer(['remove_empty_nodes' => true]);
 
 $ast = $parser->getAst();
@@ -427,7 +427,7 @@ $traverser->on('enter', function ($node) {
 
     if ($node->type == 'AtRule' && $node->name == 'media' && $node->value == 'print') {
 
-        return Traverser::IGNORE_NODE;
+        return NodeWalker::IGNORE_NODE;
     }
 });
 
@@ -439,12 +439,12 @@ Example using an Element instance
 
 ```php
 
-use TBela\CSS\Ast\Traverser;
+use TBela\CSS\Ast\NodeWalker;
 use TBela\CSS\Parser;
 use TBela\CSS\Renderer;
 
 $parser = (new Parser())->load('ast/media.css');
-$traverser = new Traverser();
+$traverser = new NodeWalker();
 $renderer = new Renderer(['remove_empty_nodes' => true]);
 
 $element = $parser->parse();
@@ -454,7 +454,7 @@ $traverser->on('enter', function ($node) {
 
     if ($node->type == 'AtRule' && $node->name == 'media' && $node->value == 'print') {
 
-        return Traverser::IGNORE_NODE;
+        return NodeWalker::IGNORE_NODE;
     }
 });
 

docs/traverser.md

@@ -22,15 +22,15 @@ add a callback for the specified event
 
 ```php
 
-use TBela\CSS\Ast\Traverser;
+use TBela\CSS\Ast\NodeWalker;
 
-$traverser = new Traverser();
+$traverser = new NodeWalker();
 $callable = function ($node) {
 
     // remove @media print {}
     if ($node->type == 'AtRule' && $node->value == 'print') {
 
-        return Traverser::IGNORE_NODE;
+        return NodeWalker::IGNORE_NODE;
     }
 };
 
@@ -52,15 +52,15 @@ remove a callback for the specified event
 
 ```php
 
-use TBela\CSS\Ast\Traverser;
+use TBela\CSS\Ast\NodeWalker;
 
-$traverser = new Traverser();
+$traverser = new NodeWalker();
 $callable = function ($node) {
 
     // remove @media print {}
     if ($node->type == 'AtRule' && $node->value == 'print') {
 
-        return Traverser::IGNORE_NODE;
+        return NodeWalker::IGNORE_NODE;
     }
 };
 

src/Ast/NodeWalker.php

@@ -0,0 +1,54 @@
+<?php
+
+namespace TBela\CSS\Ast;
+
+use IteratorAggregate;
+use TBela\CSS\Interfaces\ElementInterface;
+
+/**
+ * Ast|Element walker.
+ * @package TBela\CSS\Ast
+ */
+class NodeWalker implements IteratorAggregate
+{
+
+	protected \stdClass|ElementInterface $node;
+
+	public function __construct(\stdClass|ElementInterface $node) {
+
+		$this->node = $node;
+	}
+
+	public function next(): \Generator
+	{
+
+		yield from $this->process($this->node);
+	}
+
+	protected function process(\stdClass|ElementInterface $node): \Generator
+	{
+
+		yield 'enter' => $node;
+
+		if (!empty($node->children)) {
+
+			foreach ($node->children as $child) {
+
+				yield from $this->process($child);
+			}
+		}
+
+		if (!str_starts_with($node->type, 'Invalid') && !in_array($node->type, ['Comment', 'Declaration'])) {
+
+			yield 'exit' => $node;
+		}
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function getIterator(): iterable
+	{
+		return $this->process($this->node);
+	}
+}

src/Ast/Traverser.php

@@ -7,7 +7,7 @@
 use TBela\CSS\Value;
 
 /**
- * Ast|Element traverser
+ * Ast|Element traverser. return a modified or new tree if the callback changes a node
  * @package TBela\CSS\Ast
  */
 class Traverser extends Event