nextcloud / server

apps/dav/lib/CardDAV/SyncService.php

Indentation +241 added lines, -241 removed lines

@@ -40,245 +40,245 @@
 use Sabre\VObject\Reader;
 
 class SyncService {
-	private CardDavBackend $backend;
-	private IUserManager $userManager;
-	private LoggerInterface $logger;
-	private ?array $localSystemAddressBook = null;
-	private Converter $converter;
-	protected string $certPath;
-
-	public function __construct(CardDavBackend $backend,
-								IUserManager $userManager,
-								LoggerInterface $logger,
-								Converter $converter) {
-		$this->backend = $backend;
-		$this->userManager = $userManager;
-		$this->logger = $logger;
-		$this->converter = $converter;
-		$this->certPath = '';
-	}
-
-	/**
-	 * @throws \Exception
-	 */
-	public function syncRemoteAddressBook(string $url, string $userName, string $addressBookUrl, string $sharedSecret, ?string $syncToken, string $targetBookHash, string $targetPrincipal, array $targetProperties): string {
-		// 1. create addressbook
-		$book = $this->ensureSystemAddressBookExists($targetPrincipal, $targetBookHash, $targetProperties);
-		$addressBookId = $book['id'];
-
-		// 2. query changes
-		try {
-			$response = $this->requestSyncReport($url, $userName, $addressBookUrl, $sharedSecret, $syncToken);
-		} catch (ClientHttpException $ex) {
-			if ($ex->getCode() === Http::STATUS_UNAUTHORIZED) {
-				// remote server revoked access to the address book, remove it
-				$this->backend->deleteAddressBook($addressBookId);
-				$this->logger->error('Authorization failed, remove address book: ' . $url, ['app' => 'dav']);
-				throw $ex;
-			}
-			$this->logger->error('Client exception:', ['app' => 'dav', 'exception' => $ex]);
-			throw $ex;
-		}
-
-		// 3. apply changes
-		// TODO: use multi-get for download
-		foreach ($response['response'] as $resource => $status) {
-			$cardUri = basename($resource);
-			if (isset($status[200])) {
-				$vCard = $this->download($url, $userName, $sharedSecret, $resource);
-				$existingCard = $this->backend->getCard($addressBookId, $cardUri);
-				if ($existingCard === false) {
-					$this->backend->createCard($addressBookId, $cardUri, $vCard['body']);
-				} else {
-					$this->backend->updateCard($addressBookId, $cardUri, $vCard['body']);
-				}
-			} else {
-				$this->backend->deleteCard($addressBookId, $cardUri);
-			}
-		}
-
-		return $response['token'];
-	}
-
-	/**
-	 * @throws \Sabre\DAV\Exception\BadRequest
-	 */
-	public function ensureSystemAddressBookExists(string $principal, string $uri, array $properties): ?array {
-		$book = $this->backend->getAddressBooksByUri($principal, $uri);
-		if (!is_null($book)) {
-			return $book;
-		}
-		// FIXME This might break in clustered DB setup
-		$this->backend->createAddressBook($principal, $uri, $properties);
-
-		return $this->backend->getAddressBooksByUri($principal, $uri);
-	}
-
-	/**
-	 * Check if there is a valid certPath we should use
-	 */
-	protected function getCertPath(): string {
-
-		// we already have a valid certPath
-		if ($this->certPath !== '') {
-			return $this->certPath;
-		}
-
-		$certManager = \OC::$server->getCertificateManager();
-		$certPath = $certManager->getAbsoluteBundlePath();
-		if (file_exists($certPath)) {
-			$this->certPath = $certPath;
-		}
-
-		return $this->certPath;
-	}
-
-	protected function getClient(string $url, string $userName, string $sharedSecret): Client {
-		$settings = [
-			'baseUri' => $url . '/',
-			'userName' => $userName,
-			'password' => $sharedSecret,
-		];
-		$client = new Client($settings);
-		$certPath = $this->getCertPath();
-		$client->setThrowExceptions(true);
-
-		if ($certPath !== '' && strpos($url, 'http://') !== 0) {
-			$client->addCurlSetting(CURLOPT_CAINFO, $this->certPath);
-		}
-
-		return $client;
-	}
-
-	protected function requestSyncReport(string $url, string $userName, string $addressBookUrl, string $sharedSecret, ?string $syncToken): array {
-		$client = $this->getClient($url, $userName, $sharedSecret);
-
-		$body = $this->buildSyncCollectionRequestBody($syncToken);
-
-		$response = $client->request('REPORT', $addressBookUrl, $body, [
-			'Content-Type' => 'application/xml'
-		]);
-
-		return $this->parseMultiStatus($response['body']);
-	}
-
-	protected function download(string $url, string $userName, string $sharedSecret, string $resourcePath): array {
-		$client = $this->getClient($url, $userName, $sharedSecret);
-		return $client->request('GET', $resourcePath);
-	}
-
-	private function buildSyncCollectionRequestBody(?string $syncToken): string {
-		$dom = new \DOMDocument('1.0', 'UTF-8');
-		$dom->formatOutput = true;
-		$root = $dom->createElementNS('DAV:', 'd:sync-collection');
-		$sync = $dom->createElement('d:sync-token', $syncToken);
-		$prop = $dom->createElement('d:prop');
-		$cont = $dom->createElement('d:getcontenttype');
-		$etag = $dom->createElement('d:getetag');
-
-		$prop->appendChild($cont);
-		$prop->appendChild($etag);
-		$root->appendChild($sync);
-		$root->appendChild($prop);
-		$dom->appendChild($root);
-		return $dom->saveXML();
-	}
-
-	/**
-	 * @param string $body
-	 * @return array
-	 * @throws \Sabre\Xml\ParseException
-	 */
-	private function parseMultiStatus($body) {
-		$xml = new Service();
-
-		/** @var MultiStatus $multiStatus */
-		$multiStatus = $xml->expect('{DAV:}multistatus', $body);
-
-		$result = [];
-		foreach ($multiStatus->getResponses() as $response) {
-			$result[$response->getHref()] = $response->getResponseProperties();
-		}
-
-		return ['response' => $result, 'token' => $multiStatus->getSyncToken()];
-	}
-
-	/**
-	 * @param IUser $user
-	 */
-	public function updateUser(IUser $user) {
-		$systemAddressBook = $this->getLocalSystemAddressBook();
-		$addressBookId = $systemAddressBook['id'];
-		$name = $user->getBackendClassName();
-		$userId = $user->getUID();
-
-		$cardId = "$name:$userId.vcf";
-		if ($user->isEnabled()) {
-			$card = $this->backend->getCard($addressBookId, $cardId);
-			if ($card === false) {
-				$vCard = $this->converter->createCardFromUser($user);
-				if ($vCard !== null) {
-					$this->backend->createCard($addressBookId, $cardId, $vCard->serialize(), false);
-				}
-			} else {
-				$vCard = $this->converter->createCardFromUser($user);
-				if (is_null($vCard)) {
-					$this->backend->deleteCard($addressBookId, $cardId);
-				} else {
-					$this->backend->updateCard($addressBookId, $cardId, $vCard->serialize());
-				}
-			}
-		} else {
-			$this->backend->deleteCard($addressBookId, $cardId);
-		}
-	}
-
-	/**
-	 * @param IUser|string $userOrCardId
-	 */
-	public function deleteUser($userOrCardId) {
-		$systemAddressBook = $this->getLocalSystemAddressBook();
-		if ($userOrCardId instanceof IUser) {
-			$name = $userOrCardId->getBackendClassName();
-			$userId = $userOrCardId->getUID();
-
-			$userOrCardId = "$name:$userId.vcf";
-		}
-		$this->backend->deleteCard($systemAddressBook['id'], $userOrCardId);
-	}
-
-	/**
-	 * @return array|null
-	 */
-	public function getLocalSystemAddressBook() {
-		if (is_null($this->localSystemAddressBook)) {
-			$systemPrincipal = "principals/system/system";
-			$this->localSystemAddressBook = $this->ensureSystemAddressBookExists($systemPrincipal, 'system', [
-				'{' . Plugin::NS_CARDDAV . '}addressbook-description' => 'System addressbook which holds all users of this instance'
-			]);
-		}
-
-		return $this->localSystemAddressBook;
-	}
-
-	public function syncInstance(\Closure $progressCallback = null) {
-		$systemAddressBook = $this->getLocalSystemAddressBook();
-		$this->userManager->callForAllUsers(function ($user) use ($systemAddressBook, $progressCallback) {
-			$this->updateUser($user);
-			if (!is_null($progressCallback)) {
-				$progressCallback();
-			}
-		});
-
-		// remove no longer existing
-		$allCards = $this->backend->getCards($systemAddressBook['id']);
-		foreach ($allCards as $card) {
-			$vCard = Reader::read($card['carddata']);
-			$uid = isset($vCard->{'X-NEXTCLOUD-UID'}) ? $vCard->{'X-NEXTCLOUD-UID'}->getValue() : $vCard->UID->getValue();
-			// load backend and see if user exists
-			if (!$this->userManager->userExists($uid)) {
-				$this->deleteUser($card['uri']);
-			}
-		}
-	}
+    private CardDavBackend $backend;
+    private IUserManager $userManager;
+    private LoggerInterface $logger;
+    private ?array $localSystemAddressBook = null;
+    private Converter $converter;
+    protected string $certPath;
+
+    public function __construct(CardDavBackend $backend,
+                                IUserManager $userManager,
+                                LoggerInterface $logger,
+                                Converter $converter) {
+        $this->backend = $backend;
+        $this->userManager = $userManager;
+        $this->logger = $logger;
+        $this->converter = $converter;
+        $this->certPath = '';
+    }
+
+    /**
+     * @throws \Exception
+     */
+    public function syncRemoteAddressBook(string $url, string $userName, string $addressBookUrl, string $sharedSecret, ?string $syncToken, string $targetBookHash, string $targetPrincipal, array $targetProperties): string {
+        // 1. create addressbook
+        $book = $this->ensureSystemAddressBookExists($targetPrincipal, $targetBookHash, $targetProperties);
+        $addressBookId = $book['id'];
+
+        // 2. query changes
+        try {
+            $response = $this->requestSyncReport($url, $userName, $addressBookUrl, $sharedSecret, $syncToken);
+        } catch (ClientHttpException $ex) {
+            if ($ex->getCode() === Http::STATUS_UNAUTHORIZED) {
+                // remote server revoked access to the address book, remove it
+                $this->backend->deleteAddressBook($addressBookId);
+                $this->logger->error('Authorization failed, remove address book: ' . $url, ['app' => 'dav']);
+                throw $ex;
+            }
+            $this->logger->error('Client exception:', ['app' => 'dav', 'exception' => $ex]);
+            throw $ex;
+        }
+
+        // 3. apply changes
+        // TODO: use multi-get for download
+        foreach ($response['response'] as $resource => $status) {
+            $cardUri = basename($resource);
+            if (isset($status[200])) {
+                $vCard = $this->download($url, $userName, $sharedSecret, $resource);
+                $existingCard = $this->backend->getCard($addressBookId, $cardUri);
+                if ($existingCard === false) {
+                    $this->backend->createCard($addressBookId, $cardUri, $vCard['body']);
+                } else {
+                    $this->backend->updateCard($addressBookId, $cardUri, $vCard['body']);
+                }
+            } else {
+                $this->backend->deleteCard($addressBookId, $cardUri);
+            }
+        }
+
+        return $response['token'];
+    }
+
+    /**
+     * @throws \Sabre\DAV\Exception\BadRequest
+     */
+    public function ensureSystemAddressBookExists(string $principal, string $uri, array $properties): ?array {
+        $book = $this->backend->getAddressBooksByUri($principal, $uri);
+        if (!is_null($book)) {
+            return $book;
+        }
+        // FIXME This might break in clustered DB setup
+        $this->backend->createAddressBook($principal, $uri, $properties);
+
+        return $this->backend->getAddressBooksByUri($principal, $uri);
+    }
+
+    /**
+     * Check if there is a valid certPath we should use
+     */
+    protected function getCertPath(): string {
+
+        // we already have a valid certPath
+        if ($this->certPath !== '') {
+            return $this->certPath;
+        }
+
+        $certManager = \OC::$server->getCertificateManager();
+        $certPath = $certManager->getAbsoluteBundlePath();
+        if (file_exists($certPath)) {
+            $this->certPath = $certPath;
+        }
+
+        return $this->certPath;
+    }
+
+    protected function getClient(string $url, string $userName, string $sharedSecret): Client {
+        $settings = [
+            'baseUri' => $url . '/',
+            'userName' => $userName,
+            'password' => $sharedSecret,
+        ];
+        $client = new Client($settings);
+        $certPath = $this->getCertPath();
+        $client->setThrowExceptions(true);
+
+        if ($certPath !== '' && strpos($url, 'http://') !== 0) {
+            $client->addCurlSetting(CURLOPT_CAINFO, $this->certPath);
+        }
+
+        return $client;
+    }
+
+    protected function requestSyncReport(string $url, string $userName, string $addressBookUrl, string $sharedSecret, ?string $syncToken): array {
+        $client = $this->getClient($url, $userName, $sharedSecret);
+
+        $body = $this->buildSyncCollectionRequestBody($syncToken);
+
+        $response = $client->request('REPORT', $addressBookUrl, $body, [
+            'Content-Type' => 'application/xml'
+        ]);
+
+        return $this->parseMultiStatus($response['body']);
+    }
+
+    protected function download(string $url, string $userName, string $sharedSecret, string $resourcePath): array {
+        $client = $this->getClient($url, $userName, $sharedSecret);
+        return $client->request('GET', $resourcePath);
+    }
+
+    private function buildSyncCollectionRequestBody(?string $syncToken): string {
+        $dom = new \DOMDocument('1.0', 'UTF-8');
+        $dom->formatOutput = true;
+        $root = $dom->createElementNS('DAV:', 'd:sync-collection');
+        $sync = $dom->createElement('d:sync-token', $syncToken);
+        $prop = $dom->createElement('d:prop');
+        $cont = $dom->createElement('d:getcontenttype');
+        $etag = $dom->createElement('d:getetag');
+
+        $prop->appendChild($cont);
+        $prop->appendChild($etag);
+        $root->appendChild($sync);
+        $root->appendChild($prop);
+        $dom->appendChild($root);
+        return $dom->saveXML();
+    }
+
+    /**
+     * @param string $body
+     * @return array
+     * @throws \Sabre\Xml\ParseException
+     */
+    private function parseMultiStatus($body) {
+        $xml = new Service();
+
+        /** @var MultiStatus $multiStatus */
+        $multiStatus = $xml->expect('{DAV:}multistatus', $body);
+
+        $result = [];
+        foreach ($multiStatus->getResponses() as $response) {
+            $result[$response->getHref()] = $response->getResponseProperties();
+        }
+
+        return ['response' => $result, 'token' => $multiStatus->getSyncToken()];
+    }
+
+    /**
+     * @param IUser $user
+     */
+    public function updateUser(IUser $user) {
+        $systemAddressBook = $this->getLocalSystemAddressBook();
+        $addressBookId = $systemAddressBook['id'];
+        $name = $user->getBackendClassName();
+        $userId = $user->getUID();
+
+        $cardId = "$name:$userId.vcf";
+        if ($user->isEnabled()) {
+            $card = $this->backend->getCard($addressBookId, $cardId);
+            if ($card === false) {
+                $vCard = $this->converter->createCardFromUser($user);
+                if ($vCard !== null) {
+                    $this->backend->createCard($addressBookId, $cardId, $vCard->serialize(), false);
+                }
+            } else {
+                $vCard = $this->converter->createCardFromUser($user);
+                if (is_null($vCard)) {
+                    $this->backend->deleteCard($addressBookId, $cardId);
+                } else {
+                    $this->backend->updateCard($addressBookId, $cardId, $vCard->serialize());
+                }
+            }
+        } else {
+            $this->backend->deleteCard($addressBookId, $cardId);
+        }
+    }
+
+    /**
+     * @param IUser|string $userOrCardId
+     */
+    public function deleteUser($userOrCardId) {
+        $systemAddressBook = $this->getLocalSystemAddressBook();
+        if ($userOrCardId instanceof IUser) {
+            $name = $userOrCardId->getBackendClassName();
+            $userId = $userOrCardId->getUID();
+
+            $userOrCardId = "$name:$userId.vcf";
+        }
+        $this->backend->deleteCard($systemAddressBook['id'], $userOrCardId);
+    }
+
+    /**
+     * @return array|null
+     */
+    public function getLocalSystemAddressBook() {
+        if (is_null($this->localSystemAddressBook)) {
+            $systemPrincipal = "principals/system/system";
+            $this->localSystemAddressBook = $this->ensureSystemAddressBookExists($systemPrincipal, 'system', [
+                '{' . Plugin::NS_CARDDAV . '}addressbook-description' => 'System addressbook which holds all users of this instance'
+            ]);
+        }
+
+        return $this->localSystemAddressBook;
+    }
+
+    public function syncInstance(\Closure $progressCallback = null) {
+        $systemAddressBook = $this->getLocalSystemAddressBook();
+        $this->userManager->callForAllUsers(function ($user) use ($systemAddressBook, $progressCallback) {
+            $this->updateUser($user);
+            if (!is_null($progressCallback)) {
+                $progressCallback();
+            }
+        });
+
+        // remove no longer existing
+        $allCards = $this->backend->getCards($systemAddressBook['id']);
+        foreach ($allCards as $card) {
+            $vCard = Reader::read($card['carddata']);
+            $uid = isset($vCard->{'X-NEXTCLOUD-UID'}) ? $vCard->{'X-NEXTCLOUD-UID'}->getValue() : $vCard->UID->getValue();
+            // load backend and see if user exists
+            if (!$this->userManager->userExists($uid)) {
+                $this->deleteUser($card['uri']);
+            }
+        }
+    }
 }

apps/dav/lib/CardDAV/Converter.php

Indentation +96 added lines, -96 removed lines

@@ -36,100 +36,100 @@
 
 class Converter {
 
-	/** @var IAccountManager */
-	private $accountManager;
-
-	public function __construct(IAccountManager $accountManager) {
-		$this->accountManager = $accountManager;
-	}
-
-	public function createCardFromUser(IUser $user): ?VCard {
-		$userProperties = $this->accountManager->getAccount($user)->getProperties();
-
-		$uid = $user->getUID();
-		$backendClassName = $user->getBackendClassName();
-		$cloudId = $user->getCloudId();
-		$image = $this->getAvatarImage($user);
-
-		$vCard = new VCard();
-		$vCard->VERSION = '3.0';
-		$vCard->UID = md5("$backendClassName:$uid");
-	 	$vCard->add(new Text($vCard, 'X-NEXTCLOUD-UID', $uid));
-
-		$publish = false;
-
-		foreach ($userProperties as $property) {
-			$shareWithTrustedServers =
-				$property->getScope() === IAccountManager::SCOPE_FEDERATED ||
-				$property->getScope() === IAccountManager::SCOPE_PUBLISHED;
-
-			$emptyValue = $property->getValue() === '';
-
-			if ($shareWithTrustedServers && !$emptyValue) {
-				$publish = true;
-				switch ($property->getName()) {
-					case IAccountManager::PROPERTY_DISPLAYNAME:
-						$vCard->add(new Text($vCard, 'FN', $property->getValue()));
-						$vCard->add(new Text($vCard, 'N', $this->splitFullName($property->getValue())));
-						break;
-					case IAccountManager::PROPERTY_AVATAR:
-						if ($image !== null) {
-							$vCard->add('PHOTO', $image->data(), ['ENCODING' => 'b', 'TYPE' => $image->mimeType()]);
-						}
-						break;
-					case IAccountManager::PROPERTY_EMAIL:
-						$vCard->add(new Text($vCard, 'EMAIL', $property->getValue(), ['TYPE' => 'OTHER']));
-						break;
-					case IAccountManager::PROPERTY_WEBSITE:
-						$vCard->add(new Text($vCard, 'URL', $property->getValue()));
-						break;
-					case IAccountManager::PROPERTY_PHONE:
-						$vCard->add(new Text($vCard, 'TEL', $property->getValue(), ['TYPE' => 'OTHER']));
-						break;
-					case IAccountManager::PROPERTY_ADDRESS:
-						$vCard->add(new Text($vCard, 'ADR', $property->getValue(), ['TYPE' => 'OTHER']));
-						break;
-					case IAccountManager::PROPERTY_TWITTER:
-						$vCard->add(new Text($vCard, 'X-SOCIALPROFILE', $property->getValue(), ['TYPE' => 'TWITTER']));
-						break;
-				}
-			}
-		}
-
-		if ($publish && !empty($cloudId)) {
-			$vCard->add(new Text($vCard, 'CLOUD', $cloudId));
-			$vCard->validate();
-			return $vCard;
-		}
-
-		return null;
-	}
-
-	public function splitFullName(string $fullName): array {
-		// Very basic western style parsing. I'm not gonna implement
-		// https://github.com/android/platform_packages_providers_contactsprovider/blob/master/src/com/android/providers/contacts/NameSplitter.java ;)
-
-		$elements = explode(' ', $fullName);
-		$result = ['', '', '', '', ''];
-		if (count($elements) > 2) {
-			$result[0] = implode(' ', array_slice($elements, count($elements) - 1));
-			$result[1] = $elements[0];
-			$result[2] = implode(' ', array_slice($elements, 1, count($elements) - 2));
-		} elseif (count($elements) === 2) {
-			$result[0] = $elements[1];
-			$result[1] = $elements[0];
-		} else {
-			$result[0] = $elements[0];
-		}
-
-		return $result;
-	}
-
-	private function getAvatarImage(IUser $user): ?IImage {
-		try {
-			return $user->getAvatarImage(-1);
-		} catch (Exception $ex) {
-			return null;
-		}
-	}
+    /** @var IAccountManager */
+    private $accountManager;
+
+    public function __construct(IAccountManager $accountManager) {
+        $this->accountManager = $accountManager;
+    }
+
+    public function createCardFromUser(IUser $user): ?VCard {
+        $userProperties = $this->accountManager->getAccount($user)->getProperties();
+
+        $uid = $user->getUID();
+        $backendClassName = $user->getBackendClassName();
+        $cloudId = $user->getCloudId();
+        $image = $this->getAvatarImage($user);
+
+        $vCard = new VCard();
+        $vCard->VERSION = '3.0';
+        $vCard->UID = md5("$backendClassName:$uid");
+            $vCard->add(new Text($vCard, 'X-NEXTCLOUD-UID', $uid));
+
+        $publish = false;
+
+        foreach ($userProperties as $property) {
+            $shareWithTrustedServers =
+                $property->getScope() === IAccountManager::SCOPE_FEDERATED ||
+                $property->getScope() === IAccountManager::SCOPE_PUBLISHED;
+
+            $emptyValue = $property->getValue() === '';
+
+            if ($shareWithTrustedServers && !$emptyValue) {
+                $publish = true;
+                switch ($property->getName()) {
+                    case IAccountManager::PROPERTY_DISPLAYNAME:
+                        $vCard->add(new Text($vCard, 'FN', $property->getValue()));
+                        $vCard->add(new Text($vCard, 'N', $this->splitFullName($property->getValue())));
+                        break;
+                    case IAccountManager::PROPERTY_AVATAR:
+                        if ($image !== null) {
+                            $vCard->add('PHOTO', $image->data(), ['ENCODING' => 'b', 'TYPE' => $image->mimeType()]);
+                        }
+                        break;
+                    case IAccountManager::PROPERTY_EMAIL:
+                        $vCard->add(new Text($vCard, 'EMAIL', $property->getValue(), ['TYPE' => 'OTHER']));
+                        break;
+                    case IAccountManager::PROPERTY_WEBSITE:
+                        $vCard->add(new Text($vCard, 'URL', $property->getValue()));
+                        break;
+                    case IAccountManager::PROPERTY_PHONE:
+                        $vCard->add(new Text($vCard, 'TEL', $property->getValue(), ['TYPE' => 'OTHER']));
+                        break;
+                    case IAccountManager::PROPERTY_ADDRESS:
+                        $vCard->add(new Text($vCard, 'ADR', $property->getValue(), ['TYPE' => 'OTHER']));
+                        break;
+                    case IAccountManager::PROPERTY_TWITTER:
+                        $vCard->add(new Text($vCard, 'X-SOCIALPROFILE', $property->getValue(), ['TYPE' => 'TWITTER']));
+                        break;
+                }
+            }
+        }
+
+        if ($publish && !empty($cloudId)) {
+            $vCard->add(new Text($vCard, 'CLOUD', $cloudId));
+            $vCard->validate();
+            return $vCard;
+        }
+
+        return null;
+    }
+
+    public function splitFullName(string $fullName): array {
+        // Very basic western style parsing. I'm not gonna implement
+        // https://github.com/android/platform_packages_providers_contactsprovider/blob/master/src/com/android/providers/contacts/NameSplitter.java ;)
+
+        $elements = explode(' ', $fullName);
+        $result = ['', '', '', '', ''];
+        if (count($elements) > 2) {
+            $result[0] = implode(' ', array_slice($elements, count($elements) - 1));
+            $result[1] = $elements[0];
+            $result[2] = implode(' ', array_slice($elements, 1, count($elements) - 2));
+        } elseif (count($elements) === 2) {
+            $result[0] = $elements[1];
+            $result[1] = $elements[0];
+        } else {
+            $result[0] = $elements[0];
+        }
+
+        return $result;
+    }
+
+    private function getAvatarImage(IUser $user): ?IImage {
+        try {
+            return $user->getAvatarImage(-1);
+        } catch (Exception $ex) {
+            return null;
+        }
+    }
 }