nextcloud / server

apps/files_external/lib/AppInfo/Application.php

Indentation +89 added lines, -89 removed lines

@@ -68,94 +68,94 @@
  */
 class Application extends App implements IBackendProvider, IAuthMechanismProvider {
 
-	/**
-	 * Application constructor.
-	 *
-	 * @throws \OCP\AppFramework\QueryException
-	 */
-	public function __construct(array $urlParams = []) {
-		parent::__construct('files_external', $urlParams);
-
-		$container = $this->getContainer();
-
-		$container->registerService(IUserMountCache::class, function (IAppContainer $c) {
-			return $c->getServer()->query('UserMountCache');
-		});
-
-		/** @var BackendService $backendService */
-		$backendService = $container->query(BackendService::class);
-		$backendService->registerBackendProvider($this);
-		$backendService->registerAuthMechanismProvider($this);
-		$backendService->registerConfigHandler('user', function() use ($container) {
-			return $container->query(UserPlaceholderHandler::class);
-		});
-
-		// force-load auth mechanisms since some will register hooks
-		// TODO: obsolete these and use the TokenProvider to get the user's password from the session
-		$this->getAuthMechanisms();
-	}
-
-	/**
-	 * @{inheritdoc}
-	 */
-	public function getBackends() {
-		$container = $this->getContainer();
-
-		$backends = [
-			$container->query(Local::class),
-			$container->query(FTP::class),
-			$container->query(DAV::class),
-			$container->query(OwnCloud::class),
-			$container->query(SFTP::class),
-			$container->query(AmazonS3::class),
-			$container->query(Swift::class),
-			$container->query(SFTP_Key::class),
-			$container->query(SMB::class),
-			$container->query(SMB_OC::class),
-		];
-
-		return $backends;
-	}
-
-	/**
-	 * @{inheritdoc}
-	 */
-	public function getAuthMechanisms() {
-		$container = $this->getContainer();
-
-		return [
-			// AuthMechanism::SCHEME_NULL mechanism
-			$container->query(NullMechanism::class),
-
-			// AuthMechanism::SCHEME_BUILTIN mechanism
-			$container->query(Builtin::class),
-
-			// AuthMechanism::SCHEME_PASSWORD mechanisms
-			$container->query(Password::class),
-			$container->query(SessionCredentials::class),
-			$container->query(LoginCredentials::class),
-			$container->query(UserProvided::class),
-			$container->query(GlobalAuth::class),
-
-			// AuthMechanism::SCHEME_OAUTH1 mechanisms
-			$container->query(OAuth1::class),
-
-			// AuthMechanism::SCHEME_OAUTH2 mechanisms
-			$container->query(OAuth2::class),
-
-			// AuthMechanism::SCHEME_PUBLICKEY mechanisms
-			$container->query(RSA::class),
-			$container->query(RSAPrivateKey::class),
-
-			// AuthMechanism::SCHEME_OPENSTACK mechanisms
-			$container->query(OpenStackV2::class),
-			$container->query(OpenStackV3::class),
-			$container->query(Rackspace::class),
-
-			// Specialized mechanisms
-			$container->query(AccessKey::class),
-			$container->query(KerberosAuth::class),
-		];
-	}
+    /**
+     * Application constructor.
+     *
+     * @throws \OCP\AppFramework\QueryException
+     */
+    public function __construct(array $urlParams = []) {
+        parent::__construct('files_external', $urlParams);
+
+        $container = $this->getContainer();
+
+        $container->registerService(IUserMountCache::class, function (IAppContainer $c) {
+            return $c->getServer()->query('UserMountCache');
+        });
+
+        /** @var BackendService $backendService */
+        $backendService = $container->query(BackendService::class);
+        $backendService->registerBackendProvider($this);
+        $backendService->registerAuthMechanismProvider($this);
+        $backendService->registerConfigHandler('user', function() use ($container) {
+            return $container->query(UserPlaceholderHandler::class);
+        });
+
+        // force-load auth mechanisms since some will register hooks
+        // TODO: obsolete these and use the TokenProvider to get the user's password from the session
+        $this->getAuthMechanisms();
+    }
+
+    /**
+     * @{inheritdoc}
+     */
+    public function getBackends() {
+        $container = $this->getContainer();
+
+        $backends = [
+            $container->query(Local::class),
+            $container->query(FTP::class),
+            $container->query(DAV::class),
+            $container->query(OwnCloud::class),
+            $container->query(SFTP::class),
+            $container->query(AmazonS3::class),
+            $container->query(Swift::class),
+            $container->query(SFTP_Key::class),
+            $container->query(SMB::class),
+            $container->query(SMB_OC::class),
+        ];
+
+        return $backends;
+    }
+
+    /**
+     * @{inheritdoc}
+     */
+    public function getAuthMechanisms() {
+        $container = $this->getContainer();
+
+        return [
+            // AuthMechanism::SCHEME_NULL mechanism
+            $container->query(NullMechanism::class),
+
+            // AuthMechanism::SCHEME_BUILTIN mechanism
+            $container->query(Builtin::class),
+
+            // AuthMechanism::SCHEME_PASSWORD mechanisms
+            $container->query(Password::class),
+            $container->query(SessionCredentials::class),
+            $container->query(LoginCredentials::class),
+            $container->query(UserProvided::class),
+            $container->query(GlobalAuth::class),
+
+            // AuthMechanism::SCHEME_OAUTH1 mechanisms
+            $container->query(OAuth1::class),
+
+            // AuthMechanism::SCHEME_OAUTH2 mechanisms
+            $container->query(OAuth2::class),
+
+            // AuthMechanism::SCHEME_PUBLICKEY mechanisms
+            $container->query(RSA::class),
+            $container->query(RSAPrivateKey::class),
+
+            // AuthMechanism::SCHEME_OPENSTACK mechanisms
+            $container->query(OpenStackV2::class),
+            $container->query(OpenStackV3::class),
+            $container->query(Rackspace::class),
+
+            // Specialized mechanisms
+            $container->query(AccessKey::class),
+            $container->query(KerberosAuth::class),
+        ];
+    }
 
 }

apps/files_external/lib/Service/BackendService.php

Indentation +325 added lines, -325 removed lines

@@ -37,329 +37,329 @@
  */
 class BackendService {
 
-	/** Visibility constants for VisibilityTrait */
-	const VISIBILITY_NONE = 0;
-	const VISIBILITY_PERSONAL = 1;
-	const VISIBILITY_ADMIN = 2;
-	//const VISIBILITY_ALIENS = 4;
-
-	const VISIBILITY_DEFAULT = 3; // PERSONAL | ADMIN
-
-	/** Priority constants for PriorityTrait */
-	const PRIORITY_DEFAULT = 100;
-
-	/** @var IConfig */
-	protected $config;
-
-	/** @var bool */
-	private $userMountingAllowed = true;
-
-	/** @var string[] */
-	private $userMountingBackends = [];
-
-	/** @var Backend[] */
-	private $backends = [];
-
-	/** @var IBackendProvider[] */
-	private $backendProviders = [];
-
-	/** @var AuthMechanism[] */
-	private $authMechanisms = [];
-
-	/** @var IAuthMechanismProvider[] */
-	private $authMechanismProviders = [];
-
-	/** @var callable[] */
-	private $configHandlerLoaders = [];
-
-	private $configHandlers = [];
-
-	/**
-	 * @param IConfig $config
-	 */
-	public function __construct(
-		IConfig $config
-	) {
-		$this->config = $config;
-
-		// Load config values
-		if ($this->config->getAppValue('files_external', 'allow_user_mounting', 'yes') !== 'yes') {
-			$this->userMountingAllowed = false;
-		}
-		$this->userMountingBackends = explode(',',
-			$this->config->getAppValue('files_external', 'user_mounting_backends', '')
-		);
-
-		// if no backend is in the list an empty string is in the array and user mounting is disabled
-		if ($this->userMountingBackends === ['']) {
-			$this->userMountingAllowed = false;
-		}
-	}
-
-	/**
-	 * Register a backend provider
-	 *
-	 * @since 9.1.0
-	 * @param IBackendProvider $provider
-	 */
-	public function registerBackendProvider(IBackendProvider $provider) {
-		$this->backendProviders[] = $provider;
-	}
-
-	private function callForRegistrations() {
-		static $eventSent = false;
-		if(!$eventSent) {
-			\OC::$server->getEventDispatcher()->dispatch(
-				'OCA\\Files_External::loadAdditionalBackends'
-			);
-			$eventSent = true;
-		}
-	}
-
-	private function loadBackendProviders() {
-		$this->callForRegistrations();
-		foreach ($this->backendProviders as $provider) {
-			$this->registerBackends($provider->getBackends());
-		}
-		$this->backendProviders = [];
-	}
-
-	/**
-	 * Register an auth mechanism provider
-	 *
-	 * @since 9.1.0
-	 * @param IAuthMechanismProvider $provider
-	 */
-	public function registerAuthMechanismProvider(IAuthMechanismProvider $provider) {
-		$this->authMechanismProviders[] = $provider;
-	}
-
-	private function loadAuthMechanismProviders() {
-		$this->callForRegistrations();
-		foreach ($this->authMechanismProviders as $provider) {
-			$this->registerAuthMechanisms($provider->getAuthMechanisms());
-		}
-		$this->authMechanismProviders = [];
-	}
-
-	/**
-	 * Register a backend
-	 *
-	 * @deprecated 9.1.0 use registerBackendProvider()
-	 * @param Backend $backend
-	 */
-	public function registerBackend(Backend $backend) {
-		if (!$this->isAllowedUserBackend($backend)) {
-			$backend->removeVisibility(BackendService::VISIBILITY_PERSONAL);
-		}
-		foreach ($backend->getIdentifierAliases() as $alias) {
-			$this->backends[$alias] = $backend;
-		}
-	}
-
-	/**
-	 * @deprecated 9.1.0 use registerBackendProvider()
-	 * @param Backend[] $backends
-	 */
-	public function registerBackends(array $backends) {
-		foreach ($backends as $backend) {
-			$this->registerBackend($backend);
-		}
-	}
-	/**
-	 * Register an authentication mechanism
-	 *
-	 * @deprecated 9.1.0 use registerAuthMechanismProvider()
-	 * @param AuthMechanism $authMech
-	 */
-	public function registerAuthMechanism(AuthMechanism $authMech) {
-		if (!$this->isAllowedAuthMechanism($authMech)) {
-			$authMech->removeVisibility(BackendService::VISIBILITY_PERSONAL);
-		}
-		foreach ($authMech->getIdentifierAliases() as $alias) {
-			$this->authMechanisms[$alias] = $authMech;
-		}
-	}
-
-	/**
-	 * @deprecated 9.1.0 use registerAuthMechanismProvider()
-	 * @param AuthMechanism[] $mechanisms
-	 */
-	public function registerAuthMechanisms(array $mechanisms) {
-		foreach ($mechanisms as $mechanism) {
-			$this->registerAuthMechanism($mechanism);
-		}
-	}
-
-	/**
-	 * Get all backends
-	 *
-	 * @return Backend[]
-	 */
-	public function getBackends() {
-		$this->loadBackendProviders();
-		// only return real identifiers, no aliases
-		$backends = [];
-		foreach ($this->backends as $backend) {
-			$backends[$backend->getIdentifier()] = $backend;
-		}
-		return $backends;
-	}
-
-	/**
-	 * Get all available backends
-	 *
-	 * @return Backend[]
-	 */
-	public function getAvailableBackends() {
-		return array_filter($this->getBackends(), function($backend) {
-			return !$backend->checkDependencies();
-		});
-	}
-
-	/**
-	 * @param string $identifier
-	 * @return Backend|null
-	 */
-	public function getBackend($identifier) {
-		$this->loadBackendProviders();
-		if (isset($this->backends[$identifier])) {
-			return $this->backends[$identifier];
-		}
-		return null;
-	}
-
-	/**
-	 * Get all authentication mechanisms
-	 *
-	 * @return AuthMechanism[]
-	 */
-	public function getAuthMechanisms() {
-		$this->loadAuthMechanismProviders();
-		// only return real identifiers, no aliases
-		$mechanisms = [];
-		foreach ($this->authMechanisms as $mechanism) {
-			$mechanisms[$mechanism->getIdentifier()] = $mechanism;
-		}
-		return $mechanisms;
-	}
-
-	/**
-	 * Get all authentication mechanisms for schemes
-	 *
-	 * @param string[] $schemes
-	 * @return AuthMechanism[]
-	 */
-	public function getAuthMechanismsByScheme(array $schemes) {
-		return array_filter($this->getAuthMechanisms(), function($authMech) use ($schemes) {
-			return in_array($authMech->getScheme(), $schemes, true);
-		});
-	}
-
-	/**
-	 * @param string $identifier
-	 * @return AuthMechanism|null
-	 */
-	public function getAuthMechanism($identifier) {
-		$this->loadAuthMechanismProviders();
-		if (isset($this->authMechanisms[$identifier])) {
-			return $this->authMechanisms[$identifier];
-		}
-		return null;
-	}
-
-	/**
-	 * @return bool
-	 */
-	public function isUserMountingAllowed() {
-		return $this->userMountingAllowed;
-	}
-
-	/**
-	 * Check a backend if a user is allowed to mount it
-	 *
-	 * @param Backend $backend
-	 * @return bool
-	 */
-	protected function isAllowedUserBackend(Backend $backend) {
-		if ($this->userMountingAllowed &&
-			array_intersect($backend->getIdentifierAliases(), $this->userMountingBackends)
-		) {
-			return true;
-		}
-		return false;
-	}
-
-	/**
-	 * Check an authentication mechanism if a user is allowed to use it
-	 *
-	 * @param AuthMechanism $authMechanism
-	 * @return bool
-	 */
-	protected function isAllowedAuthMechanism(AuthMechanism $authMechanism) {
-		return true; // not implemented
-	}
-
-	/**
-	 * registers a configuration handler
-	 *
-	 * The function of the provided $placeholder is mostly to act a sorting
-	 * criteria, so longer placeholders are replaced first. This avoids
-	 * "$user" overwriting parts of "$userMail" and "$userLang", for example.
-	 * The provided value should not contain the $ prefix, only a-z0-9 are
-	 * allowed. Upper case letters are lower cased, the replacement is case-
-	 * insensitive.
-	 *
-	 * The configHandlerLoader should just instantiate the handler on demand.
-	 * For now all handlers are instantiated when a mount is loaded, independent
-	 * of whether the placeholder is present or not. This may change in future.
-	 *
-	 * @since 16.0.0
-	 */
-	public function registerConfigHandler(string $placeholder, callable $configHandlerLoader) {
-		$placeholder = trim(strtolower($placeholder));
-		if(!(bool)\preg_match('/^[a-z0-9]*$/', $placeholder)) {
-			throw new \RuntimeException(sprintf(
-				'Invalid placeholder %s, only [a-z0-9] are allowed', $placeholder
-			));
-		}
-		if($placeholder === '') {
-			throw new \RuntimeException('Invalid empty placeholder');
-		}
-		if(isset($this->configHandlerLoaders[$placeholder]) || isset($this->configHandlers[$placeholder])) {
-			throw new \RuntimeException(sprintf('A handler is already registered for %s', $placeholder));
-		}
-		$this->configHandlerLoaders[$placeholder] = $configHandlerLoader;
-	}
-
-	protected function loadConfigHandlers():void {
-		$this->callForRegistrations();
-		$newLoaded = false;
-		foreach ($this->configHandlerLoaders as $placeholder => $loader) {
-			$handler = $loader();
-			if(!$handler instanceof IConfigHandler) {
-				throw new \RuntimeException(sprintf(
-					'Handler for %s is not an instance of IConfigHandler', $placeholder
-				));
-			}
-			$this->configHandlers[$placeholder] = $handler;
-			$newLoaded = true;
-		}
-		$this->configHandlerLoaders = [];
-		if($newLoaded) {
-			// ensure those with longest placeholders come first,
-			// to avoid substring matches
-			uksort($this->configHandlers, function ($phA, $phB) {
-				return strlen($phB) <=> strlen($phA);
-			});
-		}
-	}
-
-	/**
-	 * @since 16.0.0
-	 */
-	public function getConfigHandlers() {
-		$this->loadConfigHandlers();
-		return $this->configHandlers;
-	}
+    /** Visibility constants for VisibilityTrait */
+    const VISIBILITY_NONE = 0;
+    const VISIBILITY_PERSONAL = 1;
+    const VISIBILITY_ADMIN = 2;
+    //const VISIBILITY_ALIENS = 4;
+
+    const VISIBILITY_DEFAULT = 3; // PERSONAL | ADMIN
+
+    /** Priority constants for PriorityTrait */
+    const PRIORITY_DEFAULT = 100;
+
+    /** @var IConfig */
+    protected $config;
+
+    /** @var bool */
+    private $userMountingAllowed = true;
+
+    /** @var string[] */
+    private $userMountingBackends = [];
+
+    /** @var Backend[] */
+    private $backends = [];
+
+    /** @var IBackendProvider[] */
+    private $backendProviders = [];
+
+    /** @var AuthMechanism[] */
+    private $authMechanisms = [];
+
+    /** @var IAuthMechanismProvider[] */
+    private $authMechanismProviders = [];
+
+    /** @var callable[] */
+    private $configHandlerLoaders = [];
+
+    private $configHandlers = [];
+
+    /**
+     * @param IConfig $config
+     */
+    public function __construct(
+        IConfig $config
+    ) {
+        $this->config = $config;
+
+        // Load config values
+        if ($this->config->getAppValue('files_external', 'allow_user_mounting', 'yes') !== 'yes') {
+            $this->userMountingAllowed = false;
+        }
+        $this->userMountingBackends = explode(',',
+            $this->config->getAppValue('files_external', 'user_mounting_backends', '')
+        );
+
+        // if no backend is in the list an empty string is in the array and user mounting is disabled
+        if ($this->userMountingBackends === ['']) {
+            $this->userMountingAllowed = false;
+        }
+    }
+
+    /**
+     * Register a backend provider
+     *
+     * @since 9.1.0
+     * @param IBackendProvider $provider
+     */
+    public function registerBackendProvider(IBackendProvider $provider) {
+        $this->backendProviders[] = $provider;
+    }
+
+    private function callForRegistrations() {
+        static $eventSent = false;
+        if(!$eventSent) {
+            \OC::$server->getEventDispatcher()->dispatch(
+                'OCA\\Files_External::loadAdditionalBackends'
+            );
+            $eventSent = true;
+        }
+    }
+
+    private function loadBackendProviders() {
+        $this->callForRegistrations();
+        foreach ($this->backendProviders as $provider) {
+            $this->registerBackends($provider->getBackends());
+        }
+        $this->backendProviders = [];
+    }
+
+    /**
+     * Register an auth mechanism provider
+     *
+     * @since 9.1.0
+     * @param IAuthMechanismProvider $provider
+     */
+    public function registerAuthMechanismProvider(IAuthMechanismProvider $provider) {
+        $this->authMechanismProviders[] = $provider;
+    }
+
+    private function loadAuthMechanismProviders() {
+        $this->callForRegistrations();
+        foreach ($this->authMechanismProviders as $provider) {
+            $this->registerAuthMechanisms($provider->getAuthMechanisms());
+        }
+        $this->authMechanismProviders = [];
+    }
+
+    /**
+     * Register a backend
+     *
+     * @deprecated 9.1.0 use registerBackendProvider()
+     * @param Backend $backend
+     */
+    public function registerBackend(Backend $backend) {
+        if (!$this->isAllowedUserBackend($backend)) {
+            $backend->removeVisibility(BackendService::VISIBILITY_PERSONAL);
+        }
+        foreach ($backend->getIdentifierAliases() as $alias) {
+            $this->backends[$alias] = $backend;
+        }
+    }
+
+    /**
+     * @deprecated 9.1.0 use registerBackendProvider()
+     * @param Backend[] $backends
+     */
+    public function registerBackends(array $backends) {
+        foreach ($backends as $backend) {
+            $this->registerBackend($backend);
+        }
+    }
+    /**
+     * Register an authentication mechanism
+     *
+     * @deprecated 9.1.0 use registerAuthMechanismProvider()
+     * @param AuthMechanism $authMech
+     */
+    public function registerAuthMechanism(AuthMechanism $authMech) {
+        if (!$this->isAllowedAuthMechanism($authMech)) {
+            $authMech->removeVisibility(BackendService::VISIBILITY_PERSONAL);
+        }
+        foreach ($authMech->getIdentifierAliases() as $alias) {
+            $this->authMechanisms[$alias] = $authMech;
+        }
+    }
+
+    /**
+     * @deprecated 9.1.0 use registerAuthMechanismProvider()
+     * @param AuthMechanism[] $mechanisms
+     */
+    public function registerAuthMechanisms(array $mechanisms) {
+        foreach ($mechanisms as $mechanism) {
+            $this->registerAuthMechanism($mechanism);
+        }
+    }
+
+    /**
+     * Get all backends
+     *
+     * @return Backend[]
+     */
+    public function getBackends() {
+        $this->loadBackendProviders();
+        // only return real identifiers, no aliases
+        $backends = [];
+        foreach ($this->backends as $backend) {
+            $backends[$backend->getIdentifier()] = $backend;
+        }
+        return $backends;
+    }
+
+    /**
+     * Get all available backends
+     *
+     * @return Backend[]
+     */
+    public function getAvailableBackends() {
+        return array_filter($this->getBackends(), function($backend) {
+            return !$backend->checkDependencies();
+        });
+    }
+
+    /**
+     * @param string $identifier
+     * @return Backend|null
+     */
+    public function getBackend($identifier) {
+        $this->loadBackendProviders();
+        if (isset($this->backends[$identifier])) {
+            return $this->backends[$identifier];
+        }
+        return null;
+    }
+
+    /**
+     * Get all authentication mechanisms
+     *
+     * @return AuthMechanism[]
+     */
+    public function getAuthMechanisms() {
+        $this->loadAuthMechanismProviders();
+        // only return real identifiers, no aliases
+        $mechanisms = [];
+        foreach ($this->authMechanisms as $mechanism) {
+            $mechanisms[$mechanism->getIdentifier()] = $mechanism;
+        }
+        return $mechanisms;
+    }
+
+    /**
+     * Get all authentication mechanisms for schemes
+     *
+     * @param string[] $schemes
+     * @return AuthMechanism[]
+     */
+    public function getAuthMechanismsByScheme(array $schemes) {
+        return array_filter($this->getAuthMechanisms(), function($authMech) use ($schemes) {
+            return in_array($authMech->getScheme(), $schemes, true);
+        });
+    }
+
+    /**
+     * @param string $identifier
+     * @return AuthMechanism|null
+     */
+    public function getAuthMechanism($identifier) {
+        $this->loadAuthMechanismProviders();
+        if (isset($this->authMechanisms[$identifier])) {
+            return $this->authMechanisms[$identifier];
+        }
+        return null;
+    }
+
+    /**
+     * @return bool
+     */
+    public function isUserMountingAllowed() {
+        return $this->userMountingAllowed;
+    }
+
+    /**
+     * Check a backend if a user is allowed to mount it
+     *
+     * @param Backend $backend
+     * @return bool
+     */
+    protected function isAllowedUserBackend(Backend $backend) {
+        if ($this->userMountingAllowed &&
+            array_intersect($backend->getIdentifierAliases(), $this->userMountingBackends)
+        ) {
+            return true;
+        }
+        return false;
+    }
+
+    /**
+     * Check an authentication mechanism if a user is allowed to use it
+     *
+     * @param AuthMechanism $authMechanism
+     * @return bool
+     */
+    protected function isAllowedAuthMechanism(AuthMechanism $authMechanism) {
+        return true; // not implemented
+    }
+
+    /**
+     * registers a configuration handler
+     *
+     * The function of the provided $placeholder is mostly to act a sorting
+     * criteria, so longer placeholders are replaced first. This avoids
+     * "$user" overwriting parts of "$userMail" and "$userLang", for example.
+     * The provided value should not contain the $ prefix, only a-z0-9 are
+     * allowed. Upper case letters are lower cased, the replacement is case-
+     * insensitive.
+     *
+     * The configHandlerLoader should just instantiate the handler on demand.
+     * For now all handlers are instantiated when a mount is loaded, independent
+     * of whether the placeholder is present or not. This may change in future.
+     *
+     * @since 16.0.0
+     */
+    public function registerConfigHandler(string $placeholder, callable $configHandlerLoader) {
+        $placeholder = trim(strtolower($placeholder));
+        if(!(bool)\preg_match('/^[a-z0-9]*$/', $placeholder)) {
+            throw new \RuntimeException(sprintf(
+                'Invalid placeholder %s, only [a-z0-9] are allowed', $placeholder
+            ));
+        }
+        if($placeholder === '') {
+            throw new \RuntimeException('Invalid empty placeholder');
+        }
+        if(isset($this->configHandlerLoaders[$placeholder]) || isset($this->configHandlers[$placeholder])) {
+            throw new \RuntimeException(sprintf('A handler is already registered for %s', $placeholder));
+        }
+        $this->configHandlerLoaders[$placeholder] = $configHandlerLoader;
+    }
+
+    protected function loadConfigHandlers():void {
+        $this->callForRegistrations();
+        $newLoaded = false;
+        foreach ($this->configHandlerLoaders as $placeholder => $loader) {
+            $handler = $loader();
+            if(!$handler instanceof IConfigHandler) {
+                throw new \RuntimeException(sprintf(
+                    'Handler for %s is not an instance of IConfigHandler', $placeholder
+                ));
+            }
+            $this->configHandlers[$placeholder] = $handler;
+            $newLoaded = true;
+        }
+        $this->configHandlerLoaders = [];
+        if($newLoaded) {
+            // ensure those with longest placeholders come first,
+            // to avoid substring matches
+            uksort($this->configHandlers, function ($phA, $phB) {
+                return strlen($phB) <=> strlen($phA);
+            });
+        }
+    }
+
+    /**
+     * @since 16.0.0
+     */
+    public function getConfigHandlers() {
+        $this->loadConfigHandlers();
+        return $this->configHandlers;
+    }
 }

Spacing +7 added lines, -7 removed lines

@@ -108,7 +108,7 @@ 
 
 	private function callForRegistrations() {
 		static $eventSent = false;
-		if(!$eventSent) {
+		if (!$eventSent) {
 			\OC::$server->getEventDispatcher()->dispatch(
 				'OCA\\Files_External::loadAdditionalBackends'
 			);
@@ -318,15 +318,15 @@ 
 	 */
 	public function registerConfigHandler(string $placeholder, callable $configHandlerLoader) {
 		$placeholder = trim(strtolower($placeholder));
-		if(!(bool)\preg_match('/^[a-z0-9]*$/', $placeholder)) {
+		if (!(bool) \preg_match('/^[a-z0-9]*$/', $placeholder)) {
 			throw new \RuntimeException(sprintf(
 				'Invalid placeholder %s, only [a-z0-9] are allowed', $placeholder
 			));
 		}
-		if($placeholder === '') {
+		if ($placeholder === '') {
 			throw new \RuntimeException('Invalid empty placeholder');
 		}
-		if(isset($this->configHandlerLoaders[$placeholder]) || isset($this->configHandlers[$placeholder])) {
+		if (isset($this->configHandlerLoaders[$placeholder]) || isset($this->configHandlers[$placeholder])) {
 			throw new \RuntimeException(sprintf('A handler is already registered for %s', $placeholder));
 		}
 		$this->configHandlerLoaders[$placeholder] = $configHandlerLoader;
@@ -337,7 +337,7 @@ 
 		$newLoaded = false;
 		foreach ($this->configHandlerLoaders as $placeholder => $loader) {
 			$handler = $loader();
-			if(!$handler instanceof IConfigHandler) {
+			if (!$handler instanceof IConfigHandler) {
 				throw new \RuntimeException(sprintf(
 					'Handler for %s is not an instance of IConfigHandler', $placeholder
 				));
@@ -346,10 +346,10 @@ 
 			$newLoaded = true;
 		}
 		$this->configHandlerLoaders = [];
-		if($newLoaded) {
+		if ($newLoaded) {
 			// ensure those with longest placeholders come first,
 			// to avoid substring matches
-			uksort($this->configHandlers, function ($phA, $phB) {
+			uksort($this->configHandlers, function($phA, $phB) {
 				return strlen($phB) <=> strlen($phA);
 			});
 		}