Extract FixNesting strategy from Definition object.

git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@113 48356398-32a2-884e-a903-53898d9a118a

library/HTMLPurifier/Strategy/FixNesting.php

@@ -0,0 +1,102 @@
+<?php
+
+require_once 'HTMLPurifier/Strategy.php';
+require_once 'HTMLPurifier/Definition.php';
+
+class HTMLPurifier_Strategy_FixNesting extends HTMLPurifier_Strategy
+{
+    
+    var $definition;
+    
+    function HTMLPurifier_Definition() {
+        $this->definition = HTMLPurifier_Definition::instance();
+    }
+    
+    function execute($tokens) {
+        // insert implicit "parent" node, will be removed at end
+        array_unshift($tokens, new HTMLPurifier_Token_Start('div'));
+        $tokens[] = new HTMLPurifier_Token_End('div');
+        
+        for ($i = 0, $size = count($tokens) ; $i < $size; ) {
+            
+            $child_tokens = array();
+            
+            // scroll to the end of this node, and report number
+            for ($j = $i, $depth = 0; ; $j++) {
+                if ($tokens[$j]->type == 'start') {
+                    $depth++;
+                    // skip token assignment on first iteration
+                    if ($depth == 1) continue;
+                } elseif ($tokens[$j]->type == 'end') {
+                    $depth--;
+                    // skip token assignment on last iteration
+                    if ($depth == 0) break;
+                }
+                $child_tokens[] = $tokens[$j];
+            }
+            
+            // $i is index of start token
+            // $j is index of end token
+            
+            // have DTD child def validate children
+            $element_def = $this->definition->info[$tokens[$i]->name];
+            $result = $element_def->child_def->validateChildren($child_tokens);
+            
+            // process result
+            if ($result === true) {
+                
+                // leave the nodes as is
+                
+            } elseif($result === false) {
+                
+                // WARNING WARNING WARNING!!!
+                // While for the original DTD, there will never be
+                // cascading removal, more complex ones may have such
+                // a problem.
+                
+                // If you modify the info array such that an element
+                // that requires children may contain a child that requires
+                // children, you need to also scroll back and re-check that
+                // elements parent node
+                
+                $length = $j - $i + 1;
+                
+                // remove entire node
+                array_splice($tokens, $i, $length);
+                
+                // change size
+                $size -= $length;
+                
+                // ensure that we scroll to the next node
+                $i--;
+                
+            } else {
+                
+                $length = $j - $i - 1;
+                
+                // replace node with $result
+                array_splice($tokens, $i + 1, $length, $result);
+                
+                // change size
+                $size -= $length;
+                $size += count($result);
+                
+            }
+            
+            // scroll to next node
+            $i++;
+            while ($i < $size and $tokens[$i]->type != 'start') $i++;
+            
+        }
+        
+        // remove implicit divs
+        array_shift($tokens);
+        array_pop($tokens);
+        
+        return $tokens;
+        
+    }
+    
+}
+
+?>