.
*/
namespace Doctrine\Common;
/**
* A ClassLoader is an autoloader for class files that can be
* installed on the SPL autoload stack. It is a class loader that either loads only classes
* of a specific namespace or all namespaces and it is suitable for working together
* with other autoloaders in the SPL autoload stack.
*
* If no include path is configured through the constructor or {@link setIncludePath}, a ClassLoader
* relies on the PHP include_path
.
*
* @author Roman Borschel
* @since 2.0
*/
class ClassLoader
{
/**
* @var string PHP file extension
*/
protected $fileExtension = '.php';
/**
* @var string Current namespace
*/
protected $namespace;
/**
* @var string Current include path
*/
protected $includePath;
/**
* @var string PHP namespace separator
*/
protected $namespaceSeparator = '\\';
/**
* Creates a new ClassLoader that loads classes of the
* specified namespace from the specified include path.
*
* If no include path is given, the ClassLoader relies on the PHP include_path.
* If neither a namespace nor an include path is given, the ClassLoader will
* be responsible for loading all classes, thereby relying on the PHP include_path.
*
* @param string $ns The namespace of the classes to load.
* @param string $includePath The base include path to use.
*/
public function __construct($ns = null, $includePath = null)
{
$this->namespace = $ns;
$this->includePath = $includePath;
}
/**
* Sets the namespace separator used by classes in the namespace of this ClassLoader.
*
* @param string $sep The separator to use.
*/
public function setNamespaceSeparator($sep)
{
$this->namespaceSeparator = $sep;
}
/**
* Gets the namespace separator used by classes in the namespace of this ClassLoader.
*
* @return string
*/
public function getNamespaceSeparator()
{
return $this->namespaceSeparator;
}
/**
* Sets the base include path for all class files in the namespace of this ClassLoader.
*
* @param string $includePath
*/
public function setIncludePath($includePath)
{
$this->includePath = $includePath;
}
/**
* Gets the base include path for all class files in the namespace of this ClassLoader.
*
* @return string
*/
public function getIncludePath()
{
return $this->includePath;
}
/**
* Sets the file extension of class files in the namespace of this ClassLoader.
*
* @param string $fileExtension
*/
public function setFileExtension($fileExtension)
{
$this->fileExtension = $fileExtension;
}
/**
* Gets the file extension of class files in the namespace of this ClassLoader.
*
* @return string
*/
public function getFileExtension()
{
return $this->fileExtension;
}
/**
* Registers this ClassLoader on the SPL autoload stack.
*/
public function register()
{
spl_autoload_register(array($this, 'loadClass'));
}
/**
* Removes this ClassLoader from the SPL autoload stack.
*/
public function unregister()
{
spl_autoload_unregister(array($this, 'loadClass'));
}
/**
* Loads the given class or interface.
*
* @param string $classname The name of the class to load.
* @return boolean TRUE if the class has been successfully loaded, FALSE otherwise.
*/
public function loadClass($className)
{
if ($this->namespace !== null && strpos($className, $this->namespace.$this->namespaceSeparator) !== 0) {
return false;
}
require ($this->includePath !== null ? $this->includePath . DIRECTORY_SEPARATOR : '')
. str_replace($this->namespaceSeparator, DIRECTORY_SEPARATOR, $className)
. $this->fileExtension;
return true;
}
/**
* Asks this ClassLoader whether it can potentially load the class (file) with
* the given name.
*
* @param string $className The fully-qualified name of the class.
* @return boolean TRUE if this ClassLoader can load the class, FALSE otherwise.
*/
public function canLoadClass($className)
{
if ($this->namespace !== null && strpos($className, $this->namespace.$this->namespaceSeparator) !== 0) {
return false;
}
$file = str_replace($this->namespaceSeparator, DIRECTORY_SEPARATOR, $className) . $this->fileExtension;
if ($this->includePath !== null) {
return file_exists($this->includePath . DIRECTORY_SEPARATOR . $file);
}
return (false !== stream_resolve_include_path($file));
}
/**
* Checks whether a class with a given name exists. A class "exists" if it is either
* already defined in the current request or if there is an autoloader on the SPL
* autoload stack that is a) responsible for the class in question and b) is able to
* load a class file in which the class definition resides.
*
* If the class is not already defined, each autoloader in the SPL autoload stack
* is asked whether it is able to tell if the class exists. If the autoloader is
* a ClassLoader, {@link canLoadClass} is used, otherwise the autoload
* function of the autoloader is invoked and expected to return a value that
* evaluates to TRUE if the class (file) exists. As soon as one autoloader reports
* that the class exists, TRUE is returned.
*
* Note that, depending on what kinds of autoloaders are installed on the SPL
* autoload stack, the class (file) might already be loaded as a result of checking
* for its existence. This is not the case with a ClassLoader, who separates
* these responsibilities.
*
* @param string $className The fully-qualified name of the class.
* @return boolean TRUE if the class exists as per the definition given above, FALSE otherwise.
*/
public static function classExists($className)
{
if (class_exists($className, false) || interface_exists($className, false)) {
return true;
}
foreach (spl_autoload_functions() as $loader) {
if (is_array($loader)) { // array(???, ???)
if (is_object($loader[0])) {
if ($loader[0] instanceof ClassLoader) { // array($obj, 'methodName')
if ($loader[0]->canLoadClass($className)) {
return true;
}
} else if ($loader[0]->{$loader[1]}($className)) {
return true;
}
} else if ($loader[0]::$loader[1]($className)) { // array('ClassName', 'methodName')
return true;
}
} else if ($loader instanceof \Closure) { // function($className) {..}
if ($loader($className)) {
return true;
}
} else if (is_string($loader) && $loader($className)) { // "MyClass::loadClass"
return true;
}
}
return class_exists($className, false) || interface_exists($className, false);
}
/**
* Gets the ClassLoader from the SPL autoload stack that is responsible
* for (and is able to load) the class with the given name.
*
* @param string $className The name of the class.
* @return The ClassLoader for the class or NULL if no such ClassLoader exists.
*/
public static function getClassLoader($className)
{
foreach (spl_autoload_functions() as $loader) {
if (is_array($loader)
&& $loader[0] instanceof ClassLoader
&& $loader[0]->canLoadClass($className)
) {
return $loader[0];
}
}
return null;
}
}