web/lib/Zend/Stdlib/CallbackHandler.php
changeset 886 1e110b03ae96
parent 808 6b6c2214f778
child 1230 68c69c656a2c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/web/lib/Zend/Stdlib/CallbackHandler.php	Sun Apr 21 21:54:24 2013 +0200
@@ -0,0 +1,301 @@
+<?php
+/**
+ * Zend Framework
+ *
+ * LICENSE
+ *
+ * This source file is subject to the new BSD license that is bundled
+ * with this package in the file LICENSE.txt.
+ * It is also available through the world-wide-web at this URL:
+ * http://framework.zend.com/license/new-bsd
+ * If you did not receive a copy of the license and are unable to
+ * obtain it through the world-wide-web, please send an email
+ * to license@zend.com so we can send you a copy immediately.
+ *
+ * @category   Zend
+ * @package    Zend_Stdlib
+ * @copyright  Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license    http://framework.zend.com/license/new-bsd     New BSD License
+ */
+
+/**
+ * CallbackHandler
+ *
+ * A handler for a event, event, filterchain, etc. Abstracts PHP callbacks,
+ * primarily to allow for lazy-loading and ensuring availability of default
+ * arguments (currying).
+ *
+ * @category   Zend
+ * @package    Zend_Stdlib
+ * @copyright  Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license    http://framework.zend.com/license/new-bsd     New BSD License
+ */
+class Zend_Stdlib_CallbackHandler
+{
+    /**
+     * @var string|array PHP callback to invoke
+     */
+    protected $callback;
+
+    /**
+     * Did an error occur when testing the validity of the callback?
+     * @var bool
+     */
+    protected $error = false;
+
+    /**
+     * Callback metadata, if any
+     * @var array
+     */
+    protected $metadata;
+
+    /**
+     * Constructor
+     * 
+     * @param  string $event Event to which slot is subscribed
+     * @param  string|array|object $callback PHP callback 
+     * @param  array $options Options used by the callback handler (e.g., priority)
+     * @return void
+     */
+    public function __construct($callback, array $metadata = array())
+    {
+        $this->metadata  = $metadata;
+        $this->registerCallback($callback);
+    }
+
+    /**
+     * Error handler
+     *
+     * Used by registerCallback() when calling is_callable() to capture engine warnings.
+     * 
+     * @param  int $errno 
+     * @param  string $errstr 
+     * @return void
+     */
+    public function errorHandler($errno, $errstr)
+    {
+        $this->error = true;
+    }
+
+    /**
+     * Registers the callback provided in the constructor
+     *
+     * If you have pecl/weakref {@see http://pecl.php.net/weakref} installed, 
+     * this method provides additional behavior.
+     *
+     * If a callback is a functor, or an array callback composing an object 
+     * instance, this method will pass the object to a WeakRef instance prior
+     * to registering the callback.
+     * 
+     * @param  Callable $callback 
+     * @return void
+     */
+    protected function registerCallback($callback)
+    {
+        set_error_handler(array($this, 'errorHandler'), E_STRICT);
+        $callable = is_callable($callback);
+        restore_error_handler();
+        if (!$callable || $this->error) {
+            require_once 'Zend/Stdlib/Exception/InvalidCallbackException.php';
+            throw new Zend_Stdlib_Exception_InvalidCallbackException('Invalid callback provided; not callable');
+        }
+
+        // If pecl/weakref is not installed, simply store the callback and return
+        if (!class_exists('WeakRef')) {
+            $this->callback = $callback;
+            return;
+        }
+
+        // If WeakRef exists, we want to use it.
+
+        // If we have a non-closure object, pass it to WeakRef, and then
+        // register it.
+        if (is_object($callback) && !$callback instanceof Closure) {
+            $this->callback = new WeakRef($callback);
+            return;
+        }
+
+        // If we have a string or closure, register as-is
+        if (!is_array($callback)) {
+            $this->callback = $callback;
+            return;
+        }
+
+        list($target, $method) = $callback;
+
+        // If we have an array callback, and the first argument is not an 
+        // object, register as-is
+        if (!is_object($target)) {
+            $this->callback = $callback;
+            return;
+        }
+
+        // We have an array callback with an object as the first argument;
+        // pass it to WeakRef, and then register the new callback
+        $target = new WeakRef($target);
+        $this->callback = array($target, $method);
+    }
+
+    /**
+     * Retrieve registered callback
+     * 
+     * @return Callable
+     */
+    public function getCallback()
+    {
+        $callback = $this->callback;
+
+        // String callbacks -- simply return
+        if (is_string($callback)) {
+            return $callback;
+        }
+
+        // WeakRef callbacks -- pull it out of the object and return it
+        if ($callback instanceof WeakRef) {
+            return $callback->get();
+        }
+
+        // Non-WeakRef object callback -- return it
+        if (is_object($callback)) {
+            return $callback;
+        }
+
+        // Array callback with WeakRef object -- retrieve the object first, and 
+        // then return
+        list($target, $method) = $callback;
+        if ($target instanceof WeakRef) {
+            return array($target->get(), $method);
+        }
+
+        // Otherwise, return it
+        return $callback;
+    }
+
+    /**
+     * Invoke handler
+     * 
+     * @param  array $args Arguments to pass to callback
+     * @return mixed
+     */
+    public function call(array $args = array())
+    {
+        $callback = $this->getCallback();
+
+        $isPhp54 = version_compare(PHP_VERSION, '5.4.0rc1', '>=');
+
+        if ($isPhp54 && is_string($callback)) {
+            $this->validateStringCallbackFor54($callback);
+        }
+
+        // Minor performance tweak; use call_user_func() until > 3 arguments 
+        // reached
+        switch (count($args)) {
+            case 0:
+                if ($isPhp54) {
+                    return $callback();
+                }
+                return call_user_func($callback);
+            case 1:
+                if ($isPhp54) {
+                    return $callback(array_shift($args));
+                }
+                return call_user_func($callback, array_shift($args));
+            case 2:
+                $arg1 = array_shift($args);
+                $arg2 = array_shift($args);
+                if ($isPhp54) {
+                    return $callback($arg1, $arg2);
+                }
+                return call_user_func($callback, $arg1, $arg2);
+            case 3:
+                $arg1 = array_shift($args);
+                $arg2 = array_shift($args);
+                $arg3 = array_shift($args);
+                if ($isPhp54) {
+                    return $callback($arg1, $arg2, $arg3);
+                }
+                return call_user_func($callback, $arg1, $arg2, $arg3);
+            default:
+                return call_user_func_array($callback, $args);
+        }
+    }
+
+    /**
+     * Invoke as functor
+     * 
+     * @return mixed
+     */
+    public function __invoke()
+    {
+        return $this->call(func_get_args());
+    }
+
+    /**
+     * Get all callback metadata
+     * 
+     * @return array
+     */
+    public function getMetadata()
+    {
+        return $this->metadata;
+    }
+
+    /**
+     * Retrieve a single metadatum
+     * 
+     * @param  string $name 
+     * @return mixed
+     */
+    public function getMetadatum($name)
+    {
+        if (array_key_exists($name, $this->metadata)) {
+            return $this->metadata[$name];
+        }
+        return null;
+    }
+
+    /**
+     * Validate a static method call
+     *
+     * Validates that a static method call in PHP 5.4 will actually work
+     * 
+     * @param  string $callback 
+     * @return true
+     * @throws Zend_Stdlib_Exception_InvalidCallbackException if invalid
+     */
+    protected function validateStringCallbackFor54($callback)
+    {
+        if (!strstr($callback, '::')) {
+            return true;
+        }
+
+        list($class, $method) = explode('::', $callback, 2);
+
+        if (!class_exists($class)) {
+            require_once 'Zend/Stdlib/Exception/InvalidCallbackException.php';
+            throw new Zend_Stdlib_Exception_InvalidCallbackException(sprintf(
+                'Static method call "%s" refers to a class that does not exist',
+                $callback
+            ));
+        }
+
+        $r = new ReflectionClass($class);
+        if (!$r->hasMethod($method)) {
+            require_once 'Zend/Stdlib/Exception/InvalidCallbackException.php';
+            throw new Zend_Stdlib_Exception_InvalidCallbackException(sprintf(
+                'Static method call "%s" refers to a method that does not exist',
+                $callback
+            ));
+        }
+        $m = $r->getMethod($method);
+        if (!$m->isStatic()) {
+            require_once 'Zend/Stdlib/Exception/InvalidCallbackException.php';
+            throw new Zend_Stdlib_Exception_InvalidCallbackException(sprintf(
+                'Static method call "%s" refers to a method that is not static',
+                $callback
+            ));
+        }
+
+        return true;
+    }
+}