* public static $extensions = array ( * 'Hierarchy', * "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(), $uninherited_statics = array(), $cached_uninherited_statics = array(), $extra_statics = array(), $replaced_statics = array(), $_cache_statics_prepared = 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)); $reflector = new ReflectionClass($class); if($reflector->getConstructor()) { return $reflector->newInstanceArgs($args); } return new $class; } private static $_cache_inst_args = array(); /** * Create an object from a string representation. It treats it as a PHP constructor without the * 'new' keyword. It also manages to construct the object without the use of eval(). * * Construction itself is done with Object::create(), so that Object::useCustomClass() calls * are respected. * * `Object::create_from_string("Versioned('Stage','Live')")` will return the result of * `Object::create('Versioned', 'Stage', 'Live);` * * It is designed for simple, clonable objects. The first time this method is called for a given * string it is cached, and clones of that object are returned. * * If you pass the $firstArg argument, this will be prepended to the constructor arguments. It's * impossible to pass null as the firstArg argument. * * `Object::create_from_string("Varchar(50)", "MyField")` will return the result of * `Object::create('Vachar', 'MyField', '50');` * * Arguments are always strings, although this is a quirk of the current implementation rather * than something that can be relied upon. */ static function create_from_string($classSpec, $firstArg = null) { if(!isset(self::$_cache_inst_args[$classSpec.$firstArg])) { // an $extension value can contain parameters as a string, // e.g. "Versioned('Stage','Live')" if(strpos($classSpec,'(') === false) { if($firstArg === null) self::$_cache_inst_args[$classSpec.$firstArg] = Object::create($classSpec); else self::$_cache_inst_args[$classSpec.$firstArg] = Object::create($classSpec, $firstArg); } else { list($class, $args) = self::parse_class_spec($classSpec); if($firstArg !== null) array_unshift($args, $firstArg); array_unshift($args, $class); self::$_cache_inst_args[$classSpec.$firstArg] = call_user_func_array(array('Object','create'), $args); } } return clone self::$_cache_inst_args[$classSpec.$firstArg]; } /** * Parses a class-spec, such as "Versioned('Stage','Live')", as passed to create_from_string(). * Returns a 2-elemnent array, with classname and arguments */ static function parse_class_spec($classSpec) { $tokens = token_get_all("newInstanceArgs($args); } /** * 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, $uncached = false) { if(!isset(self::$_cache_statics_prepared[$class])) { Object::prepare_statics($class); } 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, $value) { if(!isset(self::$_cache_statics_prepared[$class])) { Object::prepare_statics($class); } self::$statics[$class][$name] = $value; self::$uninherited_statics[$class][$name] = $value; self::$cached_statics[$class][$name] = true; self::$cached_uninherited_statics[$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, $uncached = false) { if(!isset(self::$_cache_statics_prepared[$class])) { Object::prepare_statics($class); } if(!isset(self::$cached_uninherited_statics[$class][$name]) || $uncached) { $classRef = new ReflectionClass($class); $classProp = $classRef->getStaticPropertyValue($name, null); $parentClass = get_parent_class($class); if($parentClass) { $parentRef = new ReflectionClass($parentClass); $parentProp = $parentRef->getStaticPropertyValue($name, null); if($parentProp == $classProp) $classProp = null; } // Add data from extra_statics if it has been applied to this specific class (it // wouldn't make sense to have them inherit in this method). This is kept separate // from the equivalent get_static code because it's so much simpler if(isset(self::$extra_statics[$class][$name])) { $toMerge = self::$extra_statics[$class][$name]; if(is_array($toMerge) && is_array($classProp)) { $classProp = array_merge($toMerge, $classProp); } elseif(!$classProp) { $classProp = $toMerge; } } self::$cached_uninherited_statics[$class][$name] = true; self::$uninherited_statics[$class][$name] = $classProp; } return self::$uninherited_statics[$class][$name]; } /** * 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; // Clear caches } else { self::$cached_statics[$class][$name] = null; self::$cached_uninherited_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($extensions = self::combined_static($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 extended - 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[$subclass]); unset(self::$extra_methods[$subclass]); } // merge with existing static vars $extensions = self::uninherited_static($class, 'extensions'); // We use unshift rather than push so that module extensions are added before built-in ones. // in particular, this ensures that the Versioned rewriting is done last. if($extensions) array_unshift($extensions, $extension); else $extensions = array($extension); self::set_static($class, 'extensions', $extensions); // load statics now for DataObject classes if(is_subclass_of($class, 'DataObject')) { if(is_subclass_of($extensionClass, 'DataExtension')) { DataExtension::load_extra_statics($class, $extension); } else { user_error("$extensionClass cannot be applied to $class without being a DataExtension", E_USER_ERROR); } } } /** * Prepare static variables before processing a {@link get_static} or {@link set_static} * call. */ private static function prepare_statics($class) { // _cache_statics_prepared setting must come first to prevent infinite loops when we call // get_static below self::$_cache_statics_prepared[$class] = true; // load statics now for DataObject classes if(is_subclass_of($class, 'DataObject')) { $extensions = Object::uninherited_static($class, 'extensions'); if($extensions) { foreach($extensions as $extension) { $extensionClass = $extension; if(preg_match('/^([^(]*)/', $extension, $matches)) { $extensionClass = $matches[1]; } if(is_subclass_of($extensionClass, 'DataExtension')) { DataExtension::load_extra_statics($class, $extension); } else { user_error("$extensionClass cannot be applied to $class without being a DataExtension", E_USER_ERROR); } } } } } /** * 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, $extension) { // unload statics now for DataObject classes if(ClassInfo::is_subclass_of($class, 'DataObject')) { if(!preg_match('/^([^(]*)/', $extension, $matches)) { user_error("Bad extension '$extension'", E_USER_WARNING); } else { $extensionClass = $matches[1]; DataObjectDecorator::unload_extra_statics($class, $extensionClass); } } if(self::has_extension($class, $extension)) { self::set_static( $class, 'extensions', array_diff(self::uninherited_static($class, 'extensions'), array($extension)) ); } // unset singletons to avoid side-effects global $_SINGLETONS; $_SINGLETONS = array(); // unset some caches self::$cached_statics[$class]['extensions'] = null; $subclasses = ClassInfo::subclassesFor($class); $subclasses[] = $class; if($subclasses) foreach($subclasses as $subclass) { unset(self::$classes_constructed[$subclass]); unset(self::$extra_methods[$subclass]); } } /** * @param string $class * @param bool $includeArgumentString Include the argument string in the return array, * FALSE would return array("Versioned"), TRUE returns array("Versioned('Stage','Live')"). * @return array Numeric array of either {@link DataExtension} classnames, * or eval'ed classname strings with constructor arguments. */ function get_extensions($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); // Don't bother checking some classes that should never be extended static $notExtendable = array('Object', 'ViewableData', 'RequestHandler'); if($extensionClasses = ClassInfo::ancestry($this->class)) foreach($extensionClasses as $class) { if(in_array($class, $notExtendable)) continue; if($extensions = self::uninherited_static($class, 'extensions')) { foreach($extensions as $extension) { $instance = self::create_from_string($extension); $instance->setOwner(null, $class); $this->extension_instances[$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, $arguments) { // If the method cache was cleared by an an Object::add_extension() / Object::remove_extension() // call, then we should rebuild it. if(empty(self::$extra_methods[get_class($this)])) { $this->defineMethods(); } $method = strtolower($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($obj) { if(!empty($config['callSetOwnerFirst'])) $obj->setOwner($this); $retVal = call_user_func_array(array($obj, $method), $arguments); if(!empty($config['callSetOwnerFirst'])) $obj->clearOwner(); return $retVal; } if($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 { // Please do not change the exception code number below. throw new Exception("Object->__call(): the method '$method' does not exist on '$this->class'", 2175); } } // ----------------------------------------------------------------------------------------------------------------- /** * 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::$built_in_methods[$this->class])) { self::$built_in_methods[$this->class] = array_map('strtolower', get_class_methods($this)); } if($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]; } } /** * 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 '

Methods defined on ' . $this->class . '

'; } } /** * Add all the methods from an object property (which is an {@link Extension}) to this object. * * @param string $property the property name * @param string|int $index an index to use if the property is an array */ protected function addMethodsFrom($property, $index = null) { $extension = ($index !== null) ? $this->{$property}[$index] : $this->$property; if(!$extension) { throw new InvalidArgumentException ( "Object->addMethodsFrom(): could not add methods from {$this->class}->{$property}[$index]" ); } if(method_exists($extension, 'allMethodNames')) { $methods = $extension->allMethodNames(true); } else { if(!isset(self::$built_in_methods[$extension->class])) { self::$built_in_methods[$extension->class] = array_map('strtolower', get_class_methods($extension)); } $methods = self::$built_in_methods[$extension->class]; } if($methods) { $methodInfo = array( 'property' => $property, 'index' => $index, 'callSetOwnerFirst' => $extension instanceof Extension, ); $newMethods = array_fill_keys($methods, $methodInfo); if(isset(self::$extra_methods[$this->class])) { self::$extra_methods[$this->class] = array_merge(self::$extra_methods[$this->class], $newMethods); } else { self::$extra_methods[$this->class] = $newMethods; } } } /** * Add a wrapper method - a method which points to another method with a different name. For example, Thumbnail(x) * can be wrapped to generateThumbnail(x) * * @param string $method the method name to wrap * @param string $wrap the method name to wrap to */ protected function addWrapperMethod($method, $wrap) { self::$extra_methods[$this->class][strtolower($method)] = array ( 'wrap' => $wrap, 'method' => $method ); } /** * Add an extra method using raw PHP code passed as a string * * @param string $method the method name * @param string $code the PHP code - arguments will be in an array called $args, while you can access this object * by using $obj. Note that you cannot call protected methods, as the method is actually an external function */ protected function createMethod($method, $code) { self::$extra_methods[$this->class][strtolower($method)] = array ( 'function' => create_function('$obj, $args', $code) ); } // ----------------------------------------------------------------------------------------------------------------- /** * @see Object::get_static() */ public function stat($name, $uncached = false) { return self::get_static(($this->class ? $this->class : get_class($this)), $name, $uncached); } /** * @see Object::set_static() */ public function set_stat($name, $value) { self::set_static(($this->class ? $this->class : get_class($this)), $name, $value); } /** * @see Object::uninherited_static() */ public function uninherited($name) { return self::uninherited_static(($this->class ? $this->class : get_class($this)), $name); } /** * @deprecated */ public function set_uninherited() { user_error ( 'Object->set_uninherited() is deprecated, please use a custom static on your object', E_USER_WARNING ); } // ----------------------------------------------------------------------------------------------------------------- /** * Return true if this object "exists" i.e. has a sensible value * * This method should be overriden in subclasses to provide more context about the classes state. For example, a * {@link DataObject} class could return false when it is deleted from the database * * @return bool */ public function exists() { return true; } /** * @return string this classes parent class */ public function parentClass() { return get_parent_class($this); } /** * Check if this class is an instance of a specific class, or has that class as one of its parents * * @param string $class * @return bool */ public function is_a($class) { return $this instanceof $class; } /** * @return string the class name */ public function __toString() { return $this->class; } // ----------------------------------------------------------------------------------------------------------------- /** * Calls a method if available on both this object and all applied {@link Extensions}, and then attempts to merge * all results into an array * * @param string $method the method name to call * @param mixed $argument a single argument to pass * @return mixed * @todo integrate inheritance rules */ public function invokeWithExtensions($method, $argument = null) { $result = method_exists($this, $method) ? array($this->$method($argument)) : array(); $extras = $this->extend($method, $argument); return $extras ? array_merge($result, $extras) : $result; } /** * Run the given function on all of this object's extensions. Note that this method originally returned void, so if * you wanted to return results, you're hosed * * Currently returns an array, with an index resulting every time the function is called. Only adds returns if * they're not NULL, to avoid bogus results from methods just defined on the parent extension. This is important for * permission-checks through extend, as they use min() to determine if any of the returns is FALSE. As min() doesn't * do type checking, an included NULL return would fail the permission checks. * * The extension methods are defined during {@link __construct()} in {@link defineMethods()}. * * @param string $method the name of the method to call on each extension * @param mixed $a1,... up to 7 arguments to be passed to the method * @return array */ public function extend($method, &$a1=null, &$a2=null, &$a3=null, &$a4=null, &$a5=null, &$a6=null, &$a7=null) { $values = array(); if($this->extension_instances) foreach($this->extension_instances as $instance) { if(method_exists($instance, $method)) { $instance->setOwner($this); $value = $instance->$method($a1, $a2, $a3, $a4, $a5, $a6, $a7); if($value !== null) $values[] = $value; $instance->clearOwner(); } } return $values; } /** * Get an extension instance attached to this object by name. * * @uses hasExtension() * * @param string $extension * @return Extension */ public function getExtensionInstance($extension) { if($this->hasExtension($extension)) return $this->extension_instances[$extension]; } /** * Returns TRUE if this object instance has a specific extension applied * in {@link $extension_instances}. Extension instances are initialized * at constructor time, meaning if you use {@link add_extension()} * afterwards, the added extension will just be added to new instances * of the extended class. Use the static method {@link has_extension()} * to check if a class (not an instance) has a specific extension. * Caution: Don't use singleton()->hasExtension() as it will * give you inconsistent results based on when the singleton was first * accessed. * * @param string $extension Classname of an {@link Extension} subclass without parameters * @return bool */ public function hasExtension($extension) { return isset($this->extension_instances[$extension]); } /** * Get all extension instances for this specific object instance. * See {@link get_extensions()} to get all applied extension classes * for this class (not the instance). * * @return array Map of {@link DataExtension} instances, keyed by classname. */ public function getExtensionInstances() { return $this->extension_instances; } // ----------------------------------------------------------------------------------------------------------------- /** * Cache the results of an instance method in this object to a file, or if it is already cache return the cached * results * * @param string $method the method name to cache * @param int $lifetime the cache lifetime in seconds * @param string $ID custom cache ID to use * @param array $arguments an optional array of arguments * @return mixed the cached data */ public function cacheToFile($method, $lifetime = 3600, $ID = false, $arguments = array()) { if(!$this->hasMethod($method)) { throw new InvalidArgumentException("Object->cacheToFile(): the method $method does not exist to cache"); } $cacheName = $this->class . '_' . $method; if(!is_array($arguments)) $arguments = array($arguments); if($ID) $cacheName .= '_' . $ID; if(count($arguments)) $cacheName .= '_' . implode('_', $arguments); if($data = $this->loadCache($cacheName, $lifetime)) { return $data; } $data = call_user_func_array(array($this, $method), $arguments); $this->saveCache($cacheName, $data); return $data; } /** * Clears the cache for the given cacheToFile call */ public function clearCache($method, $ID = false, $arguments = array()) { $cacheName = $this->class . '_' . $method; if(!is_array($arguments)) $arguments = array($arguments); if($ID) $cacheName .= '_' . $ID; if(count($arguments)) $cacheName .= '_' . implode('_', $arguments); $file = TEMP_FOLDER . '/' . $this->sanitiseCachename($cacheName); if(file_exists($file)) unlink($file); } /** * Loads a cache from the filesystem if a valid on is present and within the specified lifetime * * @param string $cache the cache name * @param int $lifetime the lifetime (in seconds) of the cache before it is invalid * @return mixed */ protected function loadCache($cache, $lifetime = 3600) { $path = TEMP_FOLDER . '/' . $this->sanitiseCachename($cache); if(!isset($_REQUEST['flush']) && file_exists($path) && (filemtime($path) + $lifetime) > time()) { return unserialize(file_get_contents($path)); } return false; } /** * Save a piece of cached data to the file system * * @param string $cache the cache name * @param mixed $data data to save (must be serializable) */ protected function saveCache($cache, $data) { file_put_contents(TEMP_FOLDER . '/' . $this->sanitiseCachename($cache), serialize($data)); } /** * Strip a file name of special characters so it is suitable for use as a cache file name * * @param string $name * @return string the name with all special cahracters replaced with underscores */ protected function sanitiseCachename($name) { return str_replace(array('~', '.', '/', '!', ' ', "\n", "\r", "\t", '\\', ':', '"', '\'', ';'), '_', $name); } }