Generic implementation of property-lists.

Signed-off-by: Edward Z. Yang <edwardzyang@thewritingpot.com>

NEWS

@@ -11,6 +11,7 @@ NEWS ( CHANGELOG and HISTORY )                                     HTMLPurifier
 
 3.3.0, unknown release date
 ! Implement CSS property 'overflow' when %CSS.AllowTricky is true.
+! Implement generic property list classess
 - Fix bug with testEncodingSupportsASCII() algorithm when iconv() implementation
   does not do the "right thing" with characters not supported in the output
   set.

library/HTMLPurifier/PropertyList.php

@@ -0,0 +1,72 @@
+<?php
+
+/**
+ * Generic property list implementation
+ */
+class HTMLPurifier_PropertyList
+{
+    /**
+     * Internal data-structure for properties
+     */
+    protected $data = array();
+
+    /**
+     * Parent plist
+     */
+    protected $parent;
+
+    /**
+     * Recursively retrieves the value for a key
+     */
+    public function get($name) {
+        if ($this->has($name)) return $this->data[$name];
+        if ($this->parent) return $this->parent->get($name);
+        throw new HTMLPurifier_Exception("Key '$name' not found");
+    }
+
+    /**
+     * Sets the value of a key, for this plist
+     */
+    public function set($name, $value) {
+        $this->data[$name] = $value;
+    }
+
+    /**
+     * Returns true if a given key exists
+     */
+    public function has($name) {
+        return array_key_exists($name, $this->data);
+    }
+
+    /**
+     * Resets a value to the value of it's parent, usually the default. If
+     * no value is specified, the entire plist is reset.
+     */
+    public function reset($name = null) {
+        if ($name == null) $this->data = array();
+        else unset($this->data[$name]);
+    }
+
+    /**
+     * Returns an iterator for traversing this array, optionally filtering
+     * for a certain prefix.
+     */
+    public function getIterator($filter = null) {
+        $a = new ArrayObject($this->data);
+        return new HTMLPurifier_PropertyListIterator($a->getIterator(), $filter);
+    }
+
+    /**
+     * Returns the parent plist.
+     */
+    public function getParent() {
+        return $this->parent;
+    }
+
+    /**
+     * Sets the parent plist.
+     */
+    public function setParent($plist) {
+        $this->parent = $plist;
+    }
+}

library/HTMLPurifier/PropertyListIterator.php

@@ -0,0 +1,30 @@
+<?php
+
+/**
+ * Property list iterator. Do not instantiate this class directly.
+ */
+class HTMLPurifier_PropertyListIterator extends FilterIterator
+{
+    
+    protected $l;
+    protected $filter;
+    
+    /**
+     * @param $data Array of data to iterate over
+     * @param $filter Optional prefix to only allow values of
+     */
+    public function __construct(Iterator $iterator, $filter = null) {
+        parent::__construct($iterator);
+        $this->l = strlen($filter);
+        $this->filter = $filter;
+    }
+    
+    public function accept() {
+        $key = $this->getInnerIterator()->key();
+        if( strncmp($key, $this->filter, $this->l) !== 0 ) {
+            return false;
+        }       
+        return true;
+    }
+    
+}

tests/HTMLPurifier/PropertyListTest.php

@@ -0,0 +1,85 @@
+<?php
+
+class HTMLPurifier_PropertyListTest extends UnitTestCase
+{
+    
+    function testBasic() {
+        $plist = new HTMLPurifier_PropertyList();
+        $plist->set('key', 'value');
+        $this->assertIdentical($plist->get('key'), 'value');
+    }
+    
+    function testNotFound() {
+        $this->expectException(new HTMLPurifier_Exception("Key 'key' not found"));
+        $plist = new HTMLPurifier_PropertyList();
+        $plist->get('key');
+    }
+    
+    function testRecursion() {
+        $parent_plist = new HTMLPurifier_PropertyList();
+        $parent_plist->set('key', 'value');
+        $plist = new HTMLPurifier_PropertyList();
+        $plist->setParent($parent_plist);
+        $this->assertIdentical($plist->get('key'), 'value');
+    }
+    
+    function testOverride() {
+        $parent_plist = new HTMLPurifier_PropertyList();
+        $parent_plist->set('key', 'value');
+        $plist = new HTMLPurifier_PropertyList();
+        $plist->setParent($parent_plist);
+        $plist->set('key',  'value2');
+        $this->assertIdentical($plist->get('key'), 'value2');
+    }
+    
+    function testRecursionNotFound() {
+        $this->expectException(new HTMLPurifier_Exception("Key 'key' not found"));
+        $parent_plist = new HTMLPurifier_PropertyList();
+        $plist = new HTMLPurifier_PropertyList();
+        $plist->setParent($parent_plist);
+        $this->assertIdentical($plist->get('key'), 'value');
+    }
+    
+    function testHas() {
+        $plist = new HTMLPurifier_PropertyList();
+        $this->assertIdentical($plist->has('key'), false);
+        $plist->set('key', 'value');
+        $this->assertIdentical($plist->has('key'), true);
+    }
+    
+    function testReset() {
+        $plist = new HTMLPurifier_PropertyList();
+        $plist->set('key1', 'value');
+        $plist->set('key2', 'value');
+        $plist->set('key3', 'value');
+        $this->assertIdentical($plist->has('key1'), true);
+        $this->assertIdentical($plist->has('key2'), true);
+        $this->assertIdentical($plist->has('key3'), true);
+        $plist->reset('key2');
+        $this->assertIdentical($plist->has('key1'), true);
+        $this->assertIdentical($plist->has('key2'), false);
+        $this->assertIdentical($plist->has('key3'), true);
+        $plist->reset();
+        $this->assertIdentical($plist->has('key1'), false);
+        $this->assertIdentical($plist->has('key2'), false);
+        $this->assertIdentical($plist->has('key3'), false);
+    }
+    
+    function testIterator() {
+        $plist = new HTMLPurifier_PropertyList();
+        $plist->set('nkey1', 'v');
+        $plist->set('nkey2', 'v');
+        $plist->set('rkey3', 'v');
+        $a = array();
+        foreach ($plist->getIterator() as $key => $value) {
+            $a[$key] = $value;
+        }
+        $this->assertIdentical($a, array('nkey1' => 'v', 'nkey2' => 'v', 'rkey3' => 'v'));
+        $a = array();
+        foreach ($plist->getIterator('nkey') as $key => $value) {
+            $a[$key] = $value;
+        }
+        $this->assertIdentical($a, array('nkey1' => 'v', 'nkey2' => 'v'));
+    }
+    
+}