icingaweb2/library/Icinga/Application/ClassLoader.php

335 lines
8.6 KiB
PHP

<?php
/* Icinga Web 2 | (c) 2013 Icinga Development Team | GPLv2+ */
namespace Icinga\Application;
use Zend_Loader_Autoloader;
/**
* PSR-4 class loader
*/
class ClassLoader
{
/**
* Namespace separator
*/
const NAMESPACE_SEPARATOR = '\\';
/**
* Icinga Web 2 module namespace prefix
*/
const MODULE_PREFIX = 'Icinga\\Module\\';
/**
* Icinga Web 2 module namespace prefix length
*
* Helps to make substr/strpos operations even faster
*/
const MODULE_PREFIX_LENGTH = 14;
/**
* A hardcoded class/subdir map for application ns prefixes
*
* When a module registers with an application directory, those
* namespace prefixes (after the module prefix) will be looked up
* in the corresponding application subdirectories
*
* @var array
*/
protected $applicationPrefixes = array(
'Clicommands' => 'clicommands',
'Controllers' => 'controllers',
'Forms' => 'forms'
);
/**
* Whether we already instantiated the ZF autoloader
*
* @var boolean
*/
protected $gotZend = false;
/**
* Namespaces
*
* @var array
*/
private $namespaces = array();
/**
* Application directories
*
* @var array
*/
private $applicationDirectories = array();
/**
* Register a base directory for a namespace prefix
*
* Application directory is optional and provides additional lookup
* logic for hardcoded namespaces like "Forms"
*
* @param string $namespace
* @param string $directory
* @param string $appDirectory
*
* @return $this
*/
public function registerNamespace($namespace, $directory, $appDirectory = null)
{
$this->namespaces[$namespace] = $directory;
if ($appDirectory !== null) {
$this->applicationDirectories[$namespace] = $appDirectory;
}
return $this;
}
/**
* Test whether a namespace exists
*
* @param string $namespace
*
* @return bool
*/
public function hasNamespace($namespace)
{
return array_key_exists($namespace, $this->namespaces);
}
/**
* Get the source file of the given class or interface
*
* @param string $class Name of the class or interface
*
* @return string|null
*/
public function getSourceFile($class)
{
if ($file = $this->getModuleSourceFile($class)) {
return $file;
}
foreach ($this->namespaces as $namespace => $dir) {
if ($class === strstr($class, "$namespace\\")) {
return $this->buildClassFilename($class, $namespace);
}
}
return null;
}
/**
* Get the source file of the given module class or interface
*
* @param string $class Module class or interface name
*
* @return string|null
*/
protected function getModuleSourceFile($class)
{
if (! $this->classBelongsToModule($class)) {
return null;
}
$modules = Icinga::app()->getModuleManager();
$namespace = $this->extractModuleNamespace($class);
if ($this->hasNamespace($namespace)) {
return $this->buildClassFilename($class, $namespace);
} elseif (! $modules->loadedAllEnabledModules()) {
$moduleName = $this->extractModuleName($class);
if ($modules->hasEnabled($moduleName)) {
$modules->loadModule($moduleName);
return $this->buildClassFilename($class, $namespace);
}
}
return null;
}
/**
* Extract the Icinga module namespace from a given namespaced class name
*
* Does no validation, prefix must have been checked before
*
* @return string
*/
protected function extractModuleNamespace($class)
{
return substr(
$class,
0,
strpos($class, self::NAMESPACE_SEPARATOR, self::MODULE_PREFIX_LENGTH + 1)
);
}
/**
* Extract the Icinga module name from a given namespaced class name
*
* Does no validation, prefix must have been checked before
*
* @return string
*/
public static function extractModuleName($class)
{
return lcfirst(
substr(
$class,
self::MODULE_PREFIX_LENGTH,
strpos(
$class,
self::NAMESPACE_SEPARATOR,
self::MODULE_PREFIX_LENGTH + 1
) - self::MODULE_PREFIX_LENGTH
)
);
}
/**
* Whether the given class name belongs to a module namespace
*
* @return boolean
*/
public static function classBelongsToModule($class)
{
return substr($class, 0, self::MODULE_PREFIX_LENGTH) === self::MODULE_PREFIX;
}
/**
* Prepare a filename string for the given class
*
* Expects the given namespace to be registered with a path name
*
* @return string
*/
protected function buildClassFilename($class, $namespace)
{
$relNs = substr($class, strlen($namespace) + 1);
if ($this->namespaceHasApplictionDirectory($namespace)) {
$prefixSeparator = strpos($relNs, self::NAMESPACE_SEPARATOR);
$prefix = substr($relNs, 0, $prefixSeparator);
if ($this->isApplicationPrefix($prefix)) {
return $this->applicationDirectories[$namespace]
. DIRECTORY_SEPARATOR
. $this->applicationPrefixes[$prefix]
. $this->classToRelativePhpFilename(substr($relNs, $prefixSeparator));
}
}
return $this->namespaces[$namespace] . DIRECTORY_SEPARATOR . $this->classToRelativePhpFilename($relNs);
}
/**
* Return the relative file name for the given (namespaces) class
*
* @param string $class
*
* @return string
*/
protected function classToRelativePhpFilename($class)
{
return str_replace(
self::NAMESPACE_SEPARATOR,
DIRECTORY_SEPARATOR,
$class
) . '.php';
}
/**
* Whether given prefix (Forms, Controllers...) makes part of "application"
*
* @param string $prefix
*
* @return boolean
*/
protected function isApplicationPrefix($prefix)
{
return array_key_exists($prefix, $this->applicationPrefixes);
}
/**
* Whether the given namespace registered an application directory
*
* @return boolean
*/
protected function namespaceHasApplictionDirectory($namespace)
{
return array_key_exists($namespace, $this->applicationDirectories);
}
/**
* Require ZF autoloader
*
* @return Zend_Loader_Autoloader
*/
protected function requireZendAutoloader()
{
require_once 'Zend/Loader/Autoloader.php';
$this->gotZend = true;
return Zend_Loader_Autoloader::getInstance();
}
/**
* Load the given class or interface
*
* @param string $class Name of the class or interface
*
* @return bool Whether the class or interface has been loaded
*/
public function loadClass($class)
{
// We are aware of the Zend_ prefix and lazyload it's autoloader.
// Return as fast as possible if we already did so.
if (substr($class, 0, 5) === 'Zend_') {
if (! $this->gotZend) {
$zendLoader = $this->requireZendAutoloader();
if (version_compare(PHP_VERSION, '7.0.0') >= 0) {
// PHP7 seems to remember the autoload function stack before auto-loading. Thus
// autoload functions registered during autoload never get called
return $zendLoader::autoload($class);
}
}
return false;
}
if ($file = $this->getSourceFile($class)) {
if (file_exists($file)) {
require $file;
return true;
}
}
return false;
}
/**
* Register {@link loadClass()} as an autoloader
*/
public function register()
{
spl_autoload_register(array($this, 'loadClass'));
}
/**
* Unregister {@link loadClass()} as an autoloader
*/
public function unregister()
{
spl_autoload_unregister(array($this, 'loadClass'));
}
/**
* Unregister this as an autoloader
*/
public function __destruct()
{
$this->unregister();
}
}