inc/3rdparty/Twig/NodeTraverser.php

   1 <?php
   2
   3 /*
   4  * This file is part of Twig.
   5  *
   6  * (c) 2009 Fabien Potencier
   7  *
   8  * For the full copyright and license information, please view the LICENSE
   9  * file that was distributed with this source code.
  10  */
  11
  12 /**
  13  * Twig_NodeTraverser is a node traverser.
  14  *
  15  * It visits all nodes and their children and call the given visitor for each.
  16  *
  17  * @author Fabien Potencier <fabien@symfony.com>
  18  */
  19 class Twig_NodeTraverser
  20 {
  21     protected $env;
  22     protected $visitors;
  23
  24     /**
  25      * Constructor.
  26      *
  27      * @param Twig_Environment $env      A Twig_Environment instance
  28      * @param array            $visitors An array of Twig_NodeVisitorInterface instances
  29      */
  30     public function __construct(Twig_Environment $env, array $visitors = array())
  31     {
  32         $this->env = $env;
  33         $this->visitors = array();
  34         foreach ($visitors as $visitor) {
  35             $this->addVisitor($visitor);
  36         }
  37     }
  38
  39     /**
  40      * Adds a visitor.
  41      *
  42      * @param Twig_NodeVisitorInterface $visitor A Twig_NodeVisitorInterface instance
  43      */
  44     public function addVisitor(Twig_NodeVisitorInterface $visitor)
  45     {
  46         if (!isset($this->visitors[$visitor->getPriority()])) {
  47             $this->visitors[$visitor->getPriority()] = array();
  48         }
  49
  50         $this->visitors[$visitor->getPriority()][] = $visitor;
  51     }
  52
  53     /**
  54      * Traverses a node and calls the registered visitors.
  55      *
  56      * @param Twig_NodeInterface $node A Twig_NodeInterface instance
  57      */
  58     public function traverse(Twig_NodeInterface $node)
  59     {
  60         ksort($this->visitors);
  61         foreach ($this->visitors as $visitors) {
  62             foreach ($visitors as $visitor) {
  63                 $node = $this->traverseForVisitor($visitor, $node);
  64             }
  65         }
  66
  67         return $node;
  68     }
  69
  70     protected function traverseForVisitor(Twig_NodeVisitorInterface $visitor, Twig_NodeInterface $node = null)
  71     {
  72         if (null === $node) {
  73             return null;
  74         }
  75
  76         $node = $visitor->enterNode($node, $this->env);
  77
  78         foreach ($node as $k => $n) {
  79             if (false !== $n = $this->traverseForVisitor($visitor, $n)) {
  80                 $node->setNode($k, $n);
  81             } else {
  82                 $node->removeNode($k);
  83             }
  84         }
  85
  86         return $visitor->leaveNode($node, $this->env);
  87     }
  88 }