silverstripe-framework/core/Object.php
Sam Minnee 9a68af98cd simon_w: #1954 - Added object caching methods
git-svn-id: svn://svn.silverstripe.com/silverstripe/open/modules/sapphire/trunk@49175 467b73ca-7a2a-4603-9d3b-597d59a354a9
2008-02-07 03:02:52 +00:00

557 lines
19 KiB
PHP
Executable File

<?php
/**
* @package sapphire
* @subpackage core
*/
/**
* Base object that all others should inherit from.
* This object provides a number of helper methods that patch over PHP's deficiencies.
* @package sapphire
* @subpackage core
*/
class Object {
/**
* This DataObjects extensions, eg Versioned.
* @var array
*/
protected $extension_instances = array();
/**
* Extensions to be used on this object. An array of extension names
* and parameters eg:
*
* static $extensions = array(
* "Hierarchy",
* "Versioned('Stage', 'Live')",
* );
*
* @var array
*/
public static $extensions = null;
protected static $extraStatics = array();
protected static $classConstructed = array();
protected static $extraMethods = array();
protected static $builtInMethods = array();
/**
* Use the class in the value instead of the class in the key
*/
private static $custom_classes = array();
private static $strong_classes = array();
/**
* This function allows you to overload class creation methods, so certain classes are
* always created correctly over your system.
*
* @param oldClass = the old classname you want to replace with.
* @param customClass = the new Classname you wish to replace the old class with.
* @param strong - If you want to force a replacement of a class then we use a different array
* e.g for use in singleton classes.
*/
public static function useCustomClass( $oldClass, $customClass,$strong = false ) {
if($strong){
self::$strong_classes[$oldClass] = $customClass;
}else{
self::$custom_classes[$oldClass] = $customClass;
}
}
public static function getCustomClass( $oldClass ) {
if( array_key_exists($oldClass, self::$custom_classes) )
return self::$custom_classes[$oldClass];
else{
return $oldClass;
}
}
/**
* Create allows us to override the standard classes of sapphire with our own custom classes.
* create will load strong classes firstly for singleton level and database interaction, otherwise will
* use the fallback custom classes.
* To set a strong custom class to overide an object at for say singleton use, use the syntax
* Object::useCustomClass('Datetime','SSDatetime',true);
* @param className - The classname you want to create
* @param args - Up to 9 arguments you wish to pass on to the new class
*/
public static function create( $className, $arg0 = null, $arg1 = null, $arg2 = null, $arg3 = null, $arg4 = null, $arg5 = null, $arg6 = null, $arg7 = null, $arg8 = null ) {
$useStrongClassName = isset(self::$strong_classes[$className]);
$useClassName = isset(self::$custom_classes[$className]);
if($useStrongClassName){
$classToCreate = self::$strong_classes[$className];
}elseif($useClassName){
$classToCreate = self::$custom_classes[$className];
}
$hasStrong = isset(self::$strong_classes[$className]) && class_exists(self::$strong_classes[$className]);
$hasNormal = isset(self::$custom_classes[$className]) && class_exists(self::$custom_classes[$className]);
if( !isset($classToCreate) || (!$hasStrong && !$hasNormal)){
$classToCreate = $className;
}
return new $classToCreate( $arg0, $arg1, $arg2, $arg3, $arg4, $arg5, $arg6, $arg7, $arg8 );
}
/**
* Strong_create is a function to enforce a certain class replacement
* e.g Php5.2's latest introduction of a namespace conflict means we have to replace
* all instances of Datetime with SSdatetime.
* this allows us to seperate those, and sapphires classes
* @param className - The class you wish to create.
* @param args - pass up to 8 arguments to the created class.
*/
public static function strong_create( $className, $arg0 = null, $arg1 = null, $arg2 = null, $arg3 = null, $arg4 = null, $arg5 = null, $arg6 = null, $arg7 = null, $arg8 = null ) {
$useStrongClassName = isset(self::$strong_classes[$className]);
if($useStrongClassName){
$classToCreate = self::$strong_classes[$className];
}
if( !isset($classToCreate) || !class_exists( self::$strong_classes[$className])){
$classToCreate = $className;
}
return new $classToCreate( $arg0, $arg1, $arg2, $arg3, $arg4, $arg5, $arg6, $arg7, $arg8 );
}
function __construct() {
$this->class = get_class($this);
// Set up the extensions
if($extensions = $this->stat('extensions')) {
foreach($extensions as $extension) {
$instance = eval("return new $extension;");
$instance->setOwner($this);
$this->extension_instances[$instance->class] = $instance;
}
}
if(!isset(Object::$classConstructed[$this->class])) {
$this->defineMethods();
Object::$classConstructed[$this->class] = true;
}
}
/**
* Returns true if this object "exists", i.e., has a sensible value.
* Overload this in subclasses.
* For example, an empty DataObject record could return false.
*/
public function exists() {
return true;
}
/**
* Returns true if the given method exists.
*/
public function hasMethod($methodName) {
if(!isset($this->class)) $this->class = get_class($this);
if(!isset(Object::$builtInMethods['_set'][$this->class])) $this->buildMethodList();
if(isset(Object::$builtInMethods[$this->class][$methodName])) return true;
if(isset(Object::$extraMethods[$this->class][$methodName])) return true;
return false;
}
/**
* Calls a method.
* Extra methods can be hooked to a class using
*/
public function __call($methodName, $args) {
if(isset(Object::$extraMethods[$this->class][$methodName])) {
$config = Object::$extraMethods[$this->class][$methodName];
if(isset($config['parameterName'])) {
if(isset($config['arrayIndex'])) $obj = $this->{$config['parameterName']}[$config['arrayIndex']];
else $obj = $this->{$config['parameterName']};
if($obj) {
return call_user_func_array(array(&$obj, $methodName), $args);
} else {
if($this->destroyed) user_error("Attempted to call $methodName on destroyed '$this->class' object", E_USER_ERROR);
else user_error("'$this->class' object doesn't have a parameter $config[parameterName]($config[arrayIndex]) to pass control to. Perhaps this object has been mistakenly destroyed?", E_USER_WARNING);
}
} else if(isset($config['wrap'])) {
array_unshift($args, $methodName);
return call_user_func_array(array(&$this, $config['wrap']), $args);
} else if(isset($config['function'])) {
$function = $config['function'];
return $function($this, $args);
} else if($config['function_str']) {
$function = Object::$extraMethods[$this->class][$methodName]['function'] = create_function('$obj, $args', $config['function_str']);
return $function($this, $args);
} else {
user_error("Object::__call() Method '$methodName' in class '$this->class' an invalid format: " . var_export(Object::$extraMethods[$this->class][$methodName],true), E_USER_ERROR);
}
} else {
user_error("Object::__call() Method '$methodName' not found in class '$this->class'", E_USER_ERROR);
}
}
/**
* Add the all methods from a given parameter to this object.
* This is used for extensions.
* @param parameterName The name of the parameter. This parameter must be instanciated with an item of the correct class.
* @param arrayIndex If parameterName is an array, this can be an index. If null, we'll assume the value is all that is needed.
*/
protected function addMethodsFrom($parameterName, $arrayIndex = null) {
$obj = isset($arrayIndex) ? $this->{$parameterName}[$arrayIndex] : $this->$parameterName;
if(!$obj) user_error("Object::addMethodsFrom: $parameterName/$arrayIndex", E_USER_ERROR);
// Hack to fix Fatal error: Call to undefined method stdClass::allMethodNames()
if(method_exists($obj, 'allMethodNames')) {
$methodNames = $obj->allMethodNames(true);
foreach($methodNames as $methodName) {
Object::$extraMethods[$this->class][$methodName] = array("parameterName" => $parameterName, "arrayIndex" => $arrayIndex);
}
}
}
/**
* Add a 'wrapper method'.
* For example, Thumbnail($arg, $arg) can be defined to call generateImage("Thumbnail", $arg, $arg)
*/
protected function addWrapperMethod($methodName, $wrapperMethod) {
Object::$extraMethods[$this->class][$methodName] = array("wrap" => $wrapperMethod);
}
/**
* Create a new method
* @param methodName The name of the method
* @param methodCode The PHP code of the method, in a string. Arguments will be contained
* in an array called $args. The object will be $obj, not $this. You won't be able to access
* any protected methods; the method is actually contained in an external function.
*/
protected function createMethod($methodName, $methodCode) {
Object::$extraMethods[$this->class][$methodName] = array("function_str" => $methodCode);
}
/**
* Return the names of all the methods on this object.
* param includeCustom If set to true, then return custom methods too.
*/
function allMethodNames($includeCustom = false) {
if(!$this->class) $this->class = get_class($this);
if(!isset(Object::$builtInMethods['_set'][$this->class])) $this->buildMethodList();
if($includeCustom && isset(Object::$extraMethods[$this->class])) {
return array_merge(Object::$builtInMethods[$this->class], array_keys(Object::$extraMethods[$this->class]));
} else {
return Object::$builtInMethods[$this->class];
}
}
function buildMethodList() {
if(!$this->class) $this->class = get_class($this);
$reflection = new ReflectionClass($this->class);
$methods = $reflection->getMethods();
foreach($methods as $method) {
$name = $method->getName();
$methodNames[$name] = $name;
}
Object::$builtInMethods[$this->class] = $methodNames;
Object::$builtInMethods['_set'][$this->class] = true ;
}
/**
* This constructor will be called the first time an object of this class is created.
* You can overload it with methods for setting up the class - for example, extra methods.
*/
protected function defineMethods() {
if($this->extension_instances) foreach($this->extension_instances as $i => $instance) {
$this->addMethodsFrom('extension_instances', $i);
}
if(isset($_REQUEST['debugmethods']) && isset(Object::$builtInMethods[$this->class])) {
Debug::require_developer_login();
echo "<h2>Methods defined for $this->class</h2>";
foreach(Object::$builtInMethods[$this->class] as $name => $info) {
echo "<li>$name";
}
}
}
/**
* This method lets us extend a built-in class by adding static variables to it
*/
static function addStaticVars($class, $statics) {
if (empty(Object::$extraStatics[$class])) {
Object::$extraStatics[$class] = (array)$statics;
} else {
$ar1 = (array)Object::$extraStatics[$class]; // First Array To Merge
$ar2 = (array)$statics; // Second Array To Merge
Object::$extraStatics[$class] = array_merge_recursive($ar1, $ar2);
}
}
function parentClass() {
return get_parent_class($this);
}
function is_a($class) {
return is_a($this, $class);
}
/**
* Set an uninherited static variable
*/
function set_uninherited($name, $val) {
return Object::$uninherited_statics[$this->class][$name] = $val;
}
/**
* Get an uninherited static variable
*/
function uninherited($name, $builtIn = false) {
// Copy a built-in value into our own array cache. PHP's static variable support is shit.
if($builtIn) {
$val = $this->stat($name);
$val2 = null;
try {
// The reflection doesn't work properly in 5.1.2
if(phpversion() == '5.1.2') {
$val2 = eval('return ' . get_parent_class($this) . "::\$$name;");
} else {
$reflection = new ReflectionClass(get_parent_class($this));
$property = $reflection->getProperty($name);
$val2 = $property->getValue();
}
} catch(Exception $exc) {
// do nothing.. the property doesn't exists!
}
return ($val != $val2) ? $val : null;
}
return isset(Object::$uninherited_statics[$this->class][$name]) ? Object::$uninherited_statics[$this->class][$name] : null;
}
protected static $statics = array();
protected static $static_cached = array();
/**
* Get a static variable
*/
function stat($name) {
if(!$this->class) $this->class = get_class($this);
if(!isset(Object::$static_cached[$this->class][$name])) {
$classes = ClassInfo::ancestry($this->class);
foreach($classes as $class) {
if(isset(Object::$extraStatics[$class][$name])) {
$extra = Object::$extraStatics[$class][$name];
if(!is_array($extra)) return $extra;
break;
}
}
$stat = eval("return {$this->class}::\$$name;");
Object::$statics[$this->class][$name] = isset($extra) ? array_merge($extra, (array)$stat) : $stat;
Object::$static_cached[$this->class][$name] = true;
}
return Object::$statics[$this->class][$name];
}
/**
* Set a static variable
*/
function set_stat($name, $val) {
Object::$statics[$this->class][$name] = $val;
Object::$static_cached[$this->class][$name] = true;
}
public $class;
private static $uninherited_statics = array();
public function __toString() {
return $this->class;
}
/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// EXTENSION METHODS
/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Run the given function on all of this object's extensions
*
* @param string $funcName The name of the function.
* @param mixed $arg An Argument to be passed to each of the extension functions.
*/
public function extend($funcName, &$arg) {
if($this->extension_instances) {
foreach($this->extension_instances as $extension) {
if($extension->hasMethod($funcName)) {
$extension->$funcName($arg);
}
}
}
}
/**
* Get an extension on this DataObject
*
* @param string $name Classname of the Extension (e.g. 'Versioned')
*
* @return DataObjectDecorator The instance of the extension
*/
public function getExtension($name) {
return $this->extension_instances[$name];
}
/**
* Returns true if the given extension class is attached to this object
*
* @param string $requiredExtension Classname of the extension
*
* @return boolean True if the given extension class is attached to this object
*/
public function hasExtension($requiredExtension) {
return isset($this->extension_instances[$requiredExtension]) ? true : false;
}
/**
* Add an extension to the given object.
* This can be used to add extensions to built-in objects, such as role decorators on Member
*/
public static function add_extension($className, $extensionName) {
Object::addStaticVars($className, array(
'extensions' => array(
$extensionName,
),
));
}
/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// CACHE METHODS (added by simon_w (simon -at- simon -dot- geek -dot- nz))
/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Loads a current cache from the filesystem, if it can.
*
* @param string $cachename The name of the cache to load
* @param int $expire The lifetime of the cache in seconds
* @return mixed The data from the cache, or false if the cache wasn't loaded
*/
protected function loadCache($cachename, $expire = 3600) {
$cache_dir = TEMP_FOLDER;
$cache_path = $cache_dir . "/" . $this->sanitiseCachename($cachename);
if((!isset($_GET['flush']) || $_GET['flush']!=1) && (@file_exists($cache_path) && ((@filemtime($cache_path) + $expire) > (time())))) {
return @unserialize(file_get_contents($cache_path));
}
return false;
}
/**
* Saves a cache to the file system
*
* @param string $cachename The name of the cache to save
* @param mixed $data The data to cache
*/
protected function saveCache($cachename, $data) {
$cache_dir = TEMP_FOLDER;
$cache_path = $cache_dir . "/" . $this->sanitiseCachename($cachename);
$fp = @fopen($cache_path, "w+");
if(!$fp) {
return; // Throw an error?
}
@fwrite($fp, @serialize($data));
@fclose($fp);
}
/**
* Makes a cache name safe to use in a file system
*
* @param string $cachename The cache name to sanitise
* @return string the sanitised cache name
*/
protected function sanitiseCachename($cachename) {
// Replace illegal characters with underscores
$cachename = str_replace(array('~', '.', '/', '!', ' ', "\n", "\r", "\t", '\\', ':', '"', '\'', ';'), '_', $cachename);
return $cachename;
}
/**
* Caches the return value of a method.
*
* @param callback $callback The method to cache
* @param int $expire The lifetime of the cache
* @param string|int $id An id for the cache
* @return mixed The cached return of the method
*/
public function cacheToFile($callback, $expire = 3600, $id = false) {
if(!$this->class) {
$this->class = get_class($this);
}
if(!method_exists($this->class, $callback)) {
user_error("Class {$this->class} doesn't have the method $callback.", E_USER_ERROR);
}
$cachename = $this->class . "_" . $callback;
if($id) {
$cachename .= "_" . (string)$id;
}
if(($data = $this->loadCache($cachename, $expire)) !== false) {
return $data;
}
// No cache to use
$data = $this->$callback();
if($data === false) {
// Some problem with function. Didn't give anything to cache. So don't cache it.
return false;
}
$this->saveCache($cachename, $data);
return $data;
}
/**
* Caches the return value of a method. Passes args to the method as well.
*
* @param callback $callback The method to cache
* @param array $args The arguments to pass to the method
* @param int $expire The lifetime of the cache
* @param string|int $id An id for the cache
* @return mixed The cached return of the method
*/
// I know this is almost exactly the same as cacheToFile, but call_user_func_array() is slow.
// Which is why there's two separate functions
public function cacheToFileWithArgs($callback, $args = array(), $expire = 3600, $id = false) {
if(!$this->class) {
$this->class = get_class($this);
}
if(!method_exists($this->class, $callback)) {
user_error("Class {$this->class} doesn't have the method $callback.", E_USER_ERROR);
}
$cachename = $this->class . "_" . $callback;
if($id) {
$cachename .= "_" . (string)$id;
}
if(($data = $this->loadCache($cachename, $expire)) !== false) {
return $data;
}
// No cache to use
$data = call_user_func_array(array($this, $callback), $args);
if($data === false) {
// Some problem with function. Didn't give anything to cache. So don't cache it.
return false;
}
$this->saveCache($cachename, $data);
return $data;
}
}
/**
* PHP 5.2 has a namespace conflict with our datetime class,
* for legacy support, we use this overload method.
* // ENFORCE STRONG_CREATE
*/
Object::useCustomClass('Datetime','SSDatetime',true);