diff -r 000000000000 -r 7f95f8617b0b vendor/symfony/src/Symfony/Component/Form/AbstractExtension.php
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/vendor/symfony/src/Symfony/Component/Form/AbstractExtension.php	Sat Sep 24 15:40:41 2011 +0200
@@ -0,0 +1,215 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Form;
+
+use Symfony\Component\Form\Exception\FormException;
+use Symfony\Component\Form\Exception\UnexpectedTypeException;
+
+/**
+ * @author Bernhard Schussek <bernhard.schussek@symfony.com>
+ */
+abstract class AbstractExtension implements FormExtensionInterface
+{
+    /**
+     * The types provided by this extension
+     * @var array An array of FormTypeInterface
+     */
+    private $types;
+
+    /**
+     * The type extensions provided by this extension
+     * @var array An array of FormTypeExtensionInterface
+     */
+    private $typeExtensions;
+
+    /**
+     * The type guesser provided by this extension
+     * @var FormTypeGuesserInterface
+     */
+    private $typeGuesser;
+
+    /**
+     * Whether the type guesser has been loaded
+     * @var Boolean
+     */
+    private $typeGuesserLoaded = false;
+
+    /**
+     * Returns a type by name.
+     *
+     * @param string $name The name of the type
+     *
+     * @return FormTypeInterface The type
+     *
+     * @throws FormException if the given type is not supported by this extension
+     */
+    public function getType($name)
+    {
+        if (null === $this->types) {
+            $this->initTypes();
+        }
+
+        if (!isset($this->types[$name])) {
+            throw new FormException(sprintf('The type "%s" can not be loaded by this extension', $name));
+        }
+
+        return $this->types[$name];
+    }
+
+    /**
+     * Returns whether the given type is supported.
+     *
+     * @param string $name The name of the type
+     *
+     * @return Boolean Whether the type is supported by this extension
+     */
+    public function hasType($name)
+    {
+        if (null === $this->types) {
+            $this->initTypes();
+        }
+
+        return isset($this->types[$name]);
+    }
+
+    /**
+     * Returns the extensions for the given type.
+     *
+     * @param string $name The name of the type
+     *
+     * @return array An array of extensions as FormTypeExtensionInterface instances
+     */
+    public function getTypeExtensions($name)
+    {
+        if (null === $this->typeExtensions) {
+            $this->initTypeExtensions();
+        }
+
+        return isset($this->typeExtensions[$name])
+            ? $this->typeExtensions[$name]
+            : array();
+    }
+
+    /**
+     * Returns whether this extension provides type extensions for the given type.
+     *
+     * @param string $name The name of the type
+     *
+     * @return Boolean Whether the given type has extensions
+     */
+    public function hasTypeExtensions($name)
+    {
+        if (null === $this->typeExtensions) {
+            $this->initTypeExtensions();
+        }
+
+        return isset($this->typeExtensions[$name]) && count($this->typeExtensions[$name]) > 0;
+    }
+
+    /**
+     * Returns the type guesser provided by this extension.
+     *
+     * @return FormTypeGuesserInterface|null The type guesser
+     */
+    public function getTypeGuesser()
+    {
+        if (!$this->typeGuesserLoaded) {
+            $this->initTypeGuesser();
+        }
+
+        return $this->typeGuesser;
+    }
+
+    /**
+     * Registers the types.
+     *
+     * @return array An array of FormTypeInterface instances
+     */
+    protected function loadTypes()
+    {
+        return array();
+    }
+
+    /**
+     * Registers the type extensions.
+     *
+     * @return array An array of FormTypeExtensionInterface instances
+     */
+    protected function loadTypeExtensions()
+    {
+        return array();
+    }
+
+    /**
+     * Registers the type guesser.
+     *
+     * @return FormTypeGuesserInterface|null A type guesser
+     */
+    protected function loadTypeGuesser()
+    {
+        return null;
+    }
+
+    /**
+     * Initializes the types.
+     *
+     * @throws UnexpectedTypeException if any registered type is not an instance of FormTypeInterface
+     */
+    private function initTypes()
+    {
+        $this->types = array();
+
+        foreach ($this->loadTypes() as $type) {
+            if (!$type instanceof FormTypeInterface) {
+                throw new UnexpectedTypeException($type, 'Symfony\Component\Form\FormTypeInterface');
+            }
+
+            $this->types[$type->getName()] = $type;
+        }
+    }
+
+    /**
+     * Initializes the type extensions.
+     *
+     * @throws UnexpectedTypeException if any registered type extension is not
+     *                                 an instance of FormTypeExtensionInterface
+     */
+    private function initTypeExtensions()
+    {
+        $this->typeExtensions = array();
+
+        foreach ($this->loadTypeExtensions() as $extension) {
+            if (!$extension instanceof FormTypeExtensionInterface) {
+                throw new UnexpectedTypeException($extension, 'Symfony\Component\Form\FormTypeExtensionInterface');
+            }
+
+            $type = $extension->getExtendedType();
+
+            $this->typeExtensions[$type][] = $extension;
+        }
+    }
+
+    /**
+     * Initializes the type guesser.
+     *
+     * @throws UnexpectedTypeException if the type guesser is not an instance of FormTypeGuesserInterface
+     */
+    private function initTypeGuesser()
+    {
+        $this->typeGuesserLoaded = true;
+
+        $this->typeGuesser = $this->loadTypeGuesser();
+        if (null !== $this->typeGuesser && !$this->typeGuesser instanceof FormTypeGuesserInterface) {
+            throw new UnexpectedTypeException($this->typeGuesser, 'Symfony\Component\Form\FormTypeGuesserInterface');
+        }
+    }
+}