* public static $extensions = array ( * 'Hierachy', * "Version('Stage', 'Live')" * ); * * * Use {@link Object::add_extension()} to add extensions without access to the class code, * e.g. to extend core classes. * * Extensions are instanciated together with the object and stored in {@link $extension_instances}. * * @var array $extensions */ public static $extensions = null; /**#@+ * @var array */ private static $statics = array(), $cached_statics = array(), $extra_statics = array(), $replaced_statics = array(); private static $classes_constructed = array(), $extra_methods = array(), $built_in_methods = array(); private static $custom_classes = array(), $strong_classes = array(); /**#@-*/ /** * @var string the class name */ public $class; /** * @var array all current extension instances. */ protected $extension_instances = array(); /** * An implementation of the factory method, allows you to create an instance of a class * * This method first for strong class overloads (singletons & DB interaction), then custom class overloads. If an * overload is found, an instance of this is returned rather than the original class. To overload a class, use * {@link Object::useCustomClass()} * * @param string $class the class name * @param mixed $arguments,... arguments to pass to the constructor * @return Object */ public static function create() { $args = func_get_args(); $class = self::getCustomClass(array_shift($args)); if(version_compare(PHP_VERSION, '5.1.3', '>=')) { $reflector = new ReflectionClass($class); return $reflector->newInstanceArgs($args); } else { // we're using a PHP install that doesn't support ReflectionClass->newInstanceArgs() $args = $args + array_fill(0, 9, null); return new $class($args[0], $args[1], $args[2], $args[3], $args[4], $args[5], $args[6], $args[7], $args[8]); } } /** * Similar to {@link Object::create()}, except that classes are only overloaded if you set the $strong parameter to * TRUE when using {@link Object::useCustomClass()} * * @param string $class the class name * @param mixed $arguments,... arguments to pass to the constructor * @return Object */ public static function strong_create() { $args = func_get_args(); $class = array_shift($args); if(isset(self::$strong_classes[$class]) && ClassInfo::exists(self::$strong_classes[$class])) { $class = self::$strong_classes[$class]; } if(version_compare(PHP_VERSION, '5.1.3', '>=')) { $reflector = new ReflectionClass($class); return $reflector->newInstanceArgs($args); } else { $args = $args + array_fill(0, 9, null); return new $class($args[0], $args[1], $args[2], $args[3], $args[4], $args[5], $args[6], $args[7], $args[8]); } } /** * This class allows you to overload classes with other classes when they are constructed using the factory method * {@link Object::create()} * * @param string $oldClass the class to replace * @param string $newClass the class to replace it with * @param bool $strong allows you to enforce a certain class replacement under all circumstances. This is used in * singletons and DB interaction classes */ public static function useCustomClass($oldClass, $newClass, $strong = false) { if($strong) { self::$strong_classes[$oldClass] = $newClass; } else { self::$custom_classes[$oldClass] = $newClass; } } /** * If a class has been overloaded, get the class name it has been overloaded with - otherwise return the class name * * @param string $class the class to check * @return string the class that would be created if you called {@link Object::create()} with the class */ public static function getCustomClass($class) { if(isset(self::$strong_classes[$class]) && ClassInfo::exists(self::$strong_classes[$class])) { return self::$strong_classes[$class]; } elseif(isset(self::$custom_classes[$class]) && ClassInfo::exists(self::$custom_classes[$class])) { return self::$custom_classes[$class]; } return $class; } /** * Get a static variable, taking into account SS's inbuild static caches and pseudo-statics * * This method first checks for any extra values added by {@link Object::add_static_var()}, and attemps to traverse * up the extra static var chain until it reaches the top, or it reaches a replacement static. * * If any extra values are discovered, they are then merged with the default PHP static values, or in some cases * completely replace the default PHP static when you set $replace = true, and do not define extra data on any child * classes * * Note that from SilverStripe 2.3.2, Object::get_static() can only be used to get public * static variables, not protected ones. * * @param string $class * @param string $name the property name * @param bool $uncached if set to TRUE, force a regeneration of the static cache * @return mixed */ public static function get_static($class, $name, $uncached = false) { if(!isset(self::$cached_statics[$class][$name]) || $uncached) { $extra = $builtIn = $break = $replacedAt = false; $ancestry = array_reverse(ClassInfo::ancestry($class)); // traverse up the class tree and build extra static and stop information foreach($ancestry as $ancestor) { if(isset(self::$extra_statics[$ancestor][$name])) { $toMerge = self::$extra_statics[$ancestor][$name]; if(is_array($toMerge) && is_array($extra)) { $extra = array_merge($toMerge, $extra); } elseif(!$extra) { $extra = $toMerge; } else { $break = true; } if(isset(self::$replaced_statics[$ancestor][$name])) $replacedAt = $break = $ancestor; if($break) break; } } // check whether to merge in the default value if($replacedAt && ($replacedAt == $class || !is_array($extra))) { $value = $extra; } elseif($replacedAt) { // determine whether to merge in lower-class variables $ancestorRef = new ReflectionClass(reset($ancestry)); $ancestorProps = $ancestorRef->getStaticProperties(); $ancestorInbuilt = array_key_exists($name, $ancestorProps) ? $ancestorProps[$name] : null; $replacedRef = new ReflectionClass($replacedAt); $replacedProps = $replacedRef->getStaticProperties(); $replacedInbuilt = array_key_exists($name, $replacedProps) ? $replacedProps[$name] : null; if($ancestorInbuilt != $replacedInbuilt) { $value = is_array($ancestorInbuilt) ? array_merge($ancestorInbuilt, (array) $extra) : $extra; } else { $value = $extra; } } else { // get a built-in value $reflector = new ReflectionClass($class); $props = $reflector->getStaticProperties(); $inbuilt = array_key_exists($name, $props) ? $props[$name] : null; $value = isset($extra) && is_array($extra) ? array_merge($extra, (array) $inbuilt) : $inbuilt; } self::$cached_statics[$class][$name] = true; self::$statics[$class][$name] = $value; } return self::$statics[$class][$name]; } /** * Set a static variable * * @param string $class * @param string $name the property name to set * @param mixed $value */ public static function set_static($class, $name, $value) { self::$statics[$class][$name] = $value; self::$cached_statics[$class][$name] = true; } /** * Get an uninherited static variable - a variable that is explicity set in this class, and not in the parent class. * * Note that from SilverStripe 2.3.2, Object::uninherited_static() can only be used to get public * static variables, not protected ones. * * @todo Recursively filter out parent statics, currently only inspects the parent class * * @param string $class * @param string $name * @return mixed */ public static function uninherited_static($class, $name) { $inherited = self::get_static($class, $name); $parent = null; if($parentClass = get_parent_class($class)) { $parent = self::get_static($parentClass, $name); } if(is_array($inherited) && is_array($parent)) { return array_diff_assoc($inherited, $parent); } return ($inherited != $parent) ? $inherited : null; } /** * Traverse down a class ancestry and attempt to merge all the uninherited static values for a particular static * into a single variable * * @param string $class * @param string $name the static name * @param string $ceiling an optional parent class name to begin merging statics down from, rather than traversing * the entire hierarchy * @return mixed */ public static function combined_static($class, $name, $ceiling = false) { $ancestry = ClassInfo::ancestry($class); $values = null; if($ceiling) while(current($ancestry) != $ceiling && $ancestry) { array_shift($ancestry); } if($ancestry) foreach($ancestry as $ancestor) { $merge = self::uninherited_static($ancestor, $name); if(is_array($values) && is_array($merge)) { $values = array_merge($values, $merge); } elseif($merge) { $values = $merge; } } return $values; } /** * Merge in a set of additional static variables * * @param string $class * @param array $properties in a [property name] => [value] format * @param bool $replace replace existing static vars */ public static function addStaticVars($class, $properties, $replace = false) { foreach($properties as $prop => $value) self::add_static_var($class, $prop, $value, $replace); } /** * Add a static variable without replacing it completely if possible, but merging in with both existing PHP statics * and existing psuedo-statics. Uses PHP's array_merge_recursive() with if the $replace argument is FALSE. * * Documentation from http://php.net/array_merge_recursive: * If the input arrays have the same string keys, then the values for these keys are merged together * into an array, and this is done recursively, so that if one of the values is an array itself, * the function will merge it with a corresponding entry in another array too. * If, however, the arrays have the same numeric key, the later value will not overwrite the original value, * but will be appended. * * @param string $class * @param string $name the static name * @param mixed $value * @param bool $replace completely replace existing static values */ public static function add_static_var($class, $name, $value, $replace = false) { if(is_array($value) && isset(self::$extra_statics[$class][$name]) && !$replace) { self::$extra_statics[$class][$name] = array_merge_recursive(self::$extra_statics[$class][$name], $value); } else { self::$extra_statics[$class][$name] = $value; } if ($replace) { self::set_static($class, $name, $value); self::$replaced_statics[$class][$name] = true; } else { self::$cached_statics[$class][$name] = null; } } /** * Return TRUE if a class has a specified extension * * @param string $class * @param string $requiredExtension the class name of the extension to check for. */ public static function has_extension($class, $requiredExtension) { $requiredExtension = strtolower($requiredExtension); if($extensions = self::get_static($class, 'extensions')) foreach($extensions as $extension) { $left = strtolower(Extension::get_classname_without_arguments($extension)); $right = strtolower(Extension::get_classname_without_arguments($requiredExtension)); if($left == $right) return true; } return false; } /** * Add an extension to a specific class. * As an alternative, extensions can be added to a specific class * directly in the {@link Object::$extensions} array. * See {@link SiteTree::$extensions} for examples. * Keep in mind that the extension will only be applied to new * instances, not existing ones (including all instances created through {@link singleton()}). * * @param string $class Class that should be decorated - has to be a subclass of {@link Object} * @param string $extension Subclass of {@link Extension} with optional parameters * as a string, e.g. "Versioned" or "Translatable('Param')" */ public static function add_extension($class, $extension) { if(!preg_match('/([^(]*)/', $extension, $matches)) { return false; } $extensionClass = $matches[1]; if(!class_exists($extensionClass)) { user_error(sprintf('Object::add_extension() - Can\'t find extension class for "%s"', $extensionClass), E_USER_ERROR); } if(!is_subclass_of($extensionClass, 'Extension')) { user_error(sprintf('Object::add_extension() - Extension "%s" is not a subclass of Extension', $extensionClass), E_USER_ERROR); } // unset some caches self::$cached_statics[$class]['extensions'] = null; $subclasses = ClassInfo::subclassesFor($class); $subclasses[] = $class; if($subclasses) foreach($subclasses as $subclass) { unset(self::$classes_constructed[$subclass]); } // merge with existing static vars self::add_static_var($class, 'extensions', array($extension)); } /** * Remove an extension from a class. * Keep in mind that this won't revert any datamodel additions * of the extension at runtime, unless its used before the * schema building kicks in (in your _config.php). * Doesn't remove the extension from any {@link Object} * instances which are already created, but will have an * effect on new extensions. * Clears any previously created singletons through {@link singleton()} * to avoid side-effects from stale extension information. * * @todo Add support for removing extensions with parameters * * @param string $class * @param string $extension Classname of an {@link Extension} subclass, without parameters */ public static function remove_extension($class, $extension) { if(self::has_extension($class, $extension)) { self::set_static( $class, 'extensions', array_diff(self::get_static($class, 'extensions'), array($extension)) ); } // unset singletons to avoid side-effects global $_SINGLETONS; $_SINGLETONS = array(); } /** * @param string $class * @param bool $includeArgumentString Include the argument string in the return array, * FALSE would return array("Versioned"), TRUE returns array("Versioned('Stage','Live')"). * @return array Numeric array of either {@link DataObjectDecorator} classnames, * or eval'ed classname strings with constructor arguments. */ function get_extensions($class, $includeArgumentString = false) { $extensions = self::get_static($class, 'extensions'); if($includeArgumentString) { return $extensions; } else { $extensionClassnames = array(); if($extensions) foreach($extensions as $extension) { $extensionClassnames[] = Extension::get_classname_without_arguments($extension); } return $extensionClassnames; } } // ----------------------------------------------------------------------------------------------------------------- public function __construct() { $this->class = get_class($this); if($extensionClasses = ClassInfo::ancestry($this->class)) foreach($extensionClasses as $class) { if($extensions = self::uninherited_static($class, 'extensions')) foreach($extensions as $extension) { // an $extension value can contain parameters as a string, // e.g. "Versioned('Stage','Live')" $instance = eval("return new $extension;"); $instance->setOwner($this); $this->extension_instances[$instance->class] = $instance; } } if(!isset(self::$classes_constructed[$this->class])) { $this->defineMethods(); self::$classes_constructed[$this->class] = true; } } /** * Attemps to locate and call a method dynamically added to a class at runtime if a default cannot be located * * You can add extra methods to a class using {@link Extensions}, {@link Object::createMethod()} or * {@link Object::addWrapperMethod()} * * @param string $method * @param array $arguments * @return mixed */ public function __call($method, $arguments) { $method = strtolower($method); if(isset(self::$extra_methods[$this->class][$method])) { $config = self::$extra_methods[$this->class][$method]; switch(true) { case isset($config['property']) : $obj = $config['index'] !== null ? $this->{$config['property']}[$config['index']] : $this->{$config['property']}; if($obj) return call_user_func_array(array($obj, $method), $arguments); if($this->destroyed) { throw new Exception ( "Object->__call(): attempt to call $method on a destroyed $this->class object" ); } else { throw new Exception ( "Object->__call(): $this->class cannot pass control to $config[property]($config[index])." . ' Perhaps this object was mistakenly destroyed?' ); } case isset($config['wrap']) : array_unshift($arguments, $config['method']); return call_user_func_array(array($this, $config['wrap']), $arguments); case isset($config['function']) : return $config['function']($this, $arguments); default : throw new Exception ( "Object->__call(): extra method $method is invalid on $this->class:" . var_export($config, true) ); } } else { throw new Exception("Object->__call(): the method '$method' does not exist on '$this->class'"); } } // ----------------------------------------------------------------------------------------------------------------- /** * Return TRUE if a method exists on this object * * This should be used rather than PHP's inbuild method_exists() as it takes into account methods added via * extensions * * @param string $method * @return bool */ public function hasMethod($method) { return method_exists($this, $method) || isset(self::$extra_methods[$this->class][strtolower($method)]); } /** * Return the names of all the methods available on this object * * @param bool $custom include methods added dynamically at runtime * @return array */ public function allMethodNames($custom = false) { if(!isset(self::$built_in_methods['_set'][$this->class])) $this->buildMethodList(); if($custom && isset(self::$extra_methods[$this->class])) { return array_merge(self::$built_in_methods[$this->class], array_keys(self::$extra_methods[$this->class])); } else { return self::$built_in_methods[$this->class]; } } protected function buildMethodList() { foreach(get_class_methods($this) as $method) { self::$built_in_methods[$this->class][strtolower($method)] = strtolower($method); } self::$built_in_methods['_set'][$this->class] = true; } /** * Adds any methods from {@link Extension} instances attached to this object. * All these methods can then be called directly on the instance (transparently * mapped through {@link __call()}), or called explicitly through {@link extend()}. * * @uses addMethodsFrom() */ protected function defineMethods() { if($this->extension_instances) foreach(array_keys($this->extension_instances) as $key) { $this->addMethodsFrom('extension_instances', $key); } if(isset($_REQUEST['debugmethods']) && isset(self::$built_in_methods[$this->class])) { Debug::require_developer_login(); echo '