[1.2.0] Commit initial implementation of Context object, we will be migrating all systems over to it next commit.

git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@482 48356398-32a2-884e-a903-53898d9a118a

library/HTMLPurifier/Context.php

@@ -0,0 +1,57 @@
+<?php
+
+/**
+ * Registry object that contains information about the current context.
+ */
+class HTMLPurifier_Context
+{
+    
+    /**
+     * Private array that stores the references.
+     * @private
+     */
+    var $_storage = array();
+    
+    /**
+     * Registers a variable into the context.
+     * @param $name String name
+     * @param $ref Variable to be registered
+     */
+    function register($name, &$ref) {
+        if (isset($this->_storage[$name])) {
+            trigger_error('Name collision, cannot re-register',
+                          E_USER_ERROR);
+            return;
+        }
+        $this->_storage[$name] =& $ref;
+    }
+    
+    /**
+     * Retrieves a variable reference from the context.
+     * @param $name String name
+     */
+    function &get($name) {
+        if (!isset($this->_storage[$name])) {
+            trigger_error('Attempted to retrieve non-existent variable',
+                          E_USER_ERROR);
+            return;
+        }
+        return $this->_storage[$name];
+    }
+    
+    /**
+     * Destorys a variable in the context.
+     * @param $name String name
+     */
+    function destroy($name) {
+        if (!isset($this->_storage[$name])) {
+            trigger_error('Attempted to destroy non-existent variable',
+                          E_USER_ERROR);
+            return;
+        }
+        unset($this->_storage[$name]);
+    }
+    
+}
+
+?>