* 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;
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;
/**
* @todo Set this via dependancy injection? Can't call it $config, because too many clashes with form elements etc
* @var Config_ForClass
*/
private $_config_forclass = null;
/**
* Get a configuration accessor for this class. Short hand for Config::inst()->get($this->class, .....).
* @return Config_ForClass|null
*/
public function config() {
if (!$this->_config_forclass) {
$this->_config_forclass = Config::inst()->forClass($this->class);
}
return $this->_config_forclass;
}
/**
* @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()}
*
* This can be called in one of two ways - either calling via the class directly,
* or calling on Object and passing the class name as the first parameter. The following
* are equivalent:
* $list = DataList::create('SiteTree');
* $list = DataList::create('SiteTree');
*
* @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 to create should be the calling class if not Object,
// otherwise the first parameter
$class = get_called_class();
if($class == 'Object')
$class = array_shift($args);
$class = self::getCustomClass($class);
$reflector = new ReflectionClass($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
* `Versioned::create('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 $firstArg argument, this will be prepended to the constructor arguments. It's
* impossible to pass null as the firstArg argument.
*
* `Object::create_from_string("Varchar(50)", "MyField")` will return the result of
* `Vachar::create('MyField', '50');`
*
* Arguments are always strings, although this is a quirk of the current implementation rather
* than something that can be relied upon.
*/
static function create_from_string($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 the value of a static property of a class, even in that property is declared protected (but not private), without any inheritance,
* merging or parent lookup if it doesn't exist on the given class
*
* In 5.3, we can do this fast using $foo::$bar syntax, but this method then needs to be in a base class of $class
* to bust the protected def
*
* @static
* @param $class - The class to get the static from
* @param $name - The property to get from the class
* @param null $default - The value to return if property doesn't exist on class
* @return any - The value of the static property $name on class $class, or $default if that property is not defined
*/
public static function static_lookup($class, $name, $default = null) {
if (version_compare(PHP_VERSION, '5.4', '>=') && is_subclass_of($class, 'Object')) {
if (isset($class::$$name)) {
$parent = get_parent_class($class);
if (!$parent || !isset($parent::$$name) || $parent::$$name !== $class::$$name) return $class::$$name;
}
return $default;
}
else {
// TODO: This gets set once, then not updated, so any changes to statics after this is called the first time for any class won't be exposed
static $static_properties = array();
if (!isset($static_properties[$class])) {
$reflection = new ReflectionClass($class);
$static_properties[$class] = $reflection->getStaticProperties();
}
if (isset($static_properties[$class][$name])) {
$value = $static_properties[$class][$name];
$parent = get_parent_class($class);
if (!$parent) return $value;
if (!isset($static_properties[$parent])) {
$reflection = new ReflectionClass($parent);
$static_properties[$parent] = $reflection->getStaticProperties();
}
if (!isset($static_properties[$parent][$name]) || $static_properties[$parent][$name] !== $value) return $value;
}
}
return $default;
}
/**
* 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
*
* @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, $uncached = false) {
Deprecation::notice('3.1.0', 'get_static is deprecated, replaced by Config#get');
return Config::inst()->get($class, $name, Config::FIRST_SET);
}
/**
* 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, $value) {
Deprecation::notice('3.1.0', 'set_static is deprecated, replaced by Config#update');
Config::inst()->update($class, $name, $value);
}
/**
* Get an uninherited static variable - a variable that is explicity set in this class, and not in the parent class.
*
* @param string $class
* @param string $name
* @return mixed
*/
public static function uninherited_static($class, $name, $uncached = false) {
Deprecation::notice('3.1.0', 'uninherited_static is deprecated, replaced by Config#get');
return Config::inst()->get($class, $name, Config::UNINHERITED);
}
/**
* 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, $ceiling = false) {
if ($ceiling) throw new Exception('Ceiling argument to combined_static is no longer supported');
Deprecation::notice('3.1.0', 'combined_static is deprecated, replaced by Config#get');
return Config::inst()->get($class, $name);
}
/**
* 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, $replace = false) {
Deprecation::notice('3.1.0', 'addStaticVars is deprecated, replaced by Config#update');
foreach($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, $replace = false) {
Deprecation::notice('3.1.0', 'add_static_var is deprecated, replaced by Config#remove and Config#update');
if ($replace) Config::inst()->remove($class, $name);
Config::inst()->update($class, $name, $value);
}
/**
* 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);
$extensions = Config::inst()->get($class, 'extensions');
if($extensions) foreach($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
$subclasses = ClassInfo::subclassesFor($class);
$subclasses[] = $class;
if($subclasses) foreach($subclasses as $subclass) {
unset(self::$classes_constructed[$subclass]);
unset(self::$extra_methods[$subclass]);
}
Config::inst()->update($class, 'extensions', array($extension));
// load statics now for DataObject classes
if(is_subclass_of($class, 'DataObject')) {
if(!is_subclass_of($extensionClass, 'DataExtension')) {
user_error("$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, $extension) {
Config::inst()->remove($class, 'extensions', Config::anything(), $extension);
// unset singletons to avoid side-effects
global $_SINGLETONS;
$_SINGLETONS = array();
// unset some caches
$subclasses = ClassInfo::subclassesFor($class);
$subclasses[] = $class;
if($subclasses) foreach($subclasses as $subclass) {
unset(self::$classes_constructed[$subclass]);
unset(self::$extra_methods[$subclass]);
}
}
/**
* @param string $class
* @param bool $includeArgumentString Include the argument string in the return array,
* FALSE would return array("Versioned"), TRUE returns array("Versioned('Stage','Live')").
* @return array Numeric array of either {@link DataExtension} classnames,
* or eval'ed classname strings with constructor arguments.
*/
public static function get_extensions($class, $includeArgumentString = false) {
$extensions = Config::inst()->get($class, 'extensions');
if($includeArgumentString) {
return $extensions;
} else {
$extensionClassnames = array();
if($extensions) foreach($extensions as $extension) {
$extensionClassnames[] = Extension::get_classname_without_arguments($extension);
}
return $extensionClassnames;
}
}
// -----------------------------------------------------------------------------------------------------------------
private static $_added_extensions = array();
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 = Config::inst()->get($class, 'extensions', Config::UNINHERITED)) {
foreach($extensions as $extension) {
// Get the extension class for this extension
list($extensionClass, $extensionArgs) = self::parse_class_spec($extension);
// If we haven't told that extension it's attached to this class yet, do that now
if (!isset(self::$_added_extensions[$extensionClass][$class])) {
// First call the add_to_class method - this will inherit down & is defined on Extension, so if not defined, no worries
call_user_func(array($extensionClass, 'add_to_class'), $class, $extensionClass, $extensionArgs);
// Then register it as having been told about us
if (!isset(self::$_added_extensions[$extensionClass])) self::$_added_extensions[$extensionClass] = array($class => true);
else self::$_added_extensions[$extensionClass][$class] = true;
}
$instance = self::create_from_string($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 ' . $this->class . '
';
foreach(self::$built_in_methods[$this->class] as $method) {
echo "- $method
";
}
echo '
';
}
}
/**
* 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, $uncached = false) {
return Config::inst()->get(($this->class ? $this->class : get_class($this)), $name, Config::FIRST_SET);
}
/**
* @see Object::set_static()
*/
public function set_stat($name, $value) {
Config::inst()->update(($this->class ? $this->class : get_class($this)), $name, $value);
}
/**
* @see Object::uninherited_static()
*/
public function uninherited($name) {
return Config::inst()->get(($this->class ? $this->class : get_class($this)), $name, Config::UNINHERITED);
}
/**
* @deprecated
*/
public function set_uninherited() {
Deprecation::notice('2.4', 'Use a custom static on your object instead.');
}
// -----------------------------------------------------------------------------------------------------------------
/**
* Return true if this object "exists" i.e. has a sensible value
*
* This method should be overriden in subclasses to provide more context about the classes state. For example, a
* {@link DataObject} class could return false when it is deleted from the database
*
* @return bool
*/
public function exists() {
return true;
}
/**
* @return string this classes parent class
*/
public function parentClass() {
return get_parent_class($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);
}
}