feat: Use new IAlternativeLoginProvider when available

Signed-off-by: Carl Schwan <carlschwan@kde.org>

Author: CarlSchwan

lib/AlternativeLogin/AlternativeLogin.php

@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\UserOIDC\AlternativeLogin;
+
+use OCP\Authentication\IAlternativeLogin;
+
+class AlternativeLogin implements IAlternativeLogin {
+	public function __construct(
+		private readonly string $name,
+		private readonly string $href,
+	) {
+	}
+
+	public function getLabel(): string {
+		return $this->name;
+	}
+
+	public function getLink(): string {
+		return $this->href;
+	}
+
+	public function getClass(): string {
+		return '';
+	}
+
+	public function load(): void {
+	}
+}

lib/AlternativeLogin/AlternativeLoginProvider.php

@@ -0,0 +1,56 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\UserOIDC\AlternativeLogin;
+
+use OCA\UserOIDC\AppInfo\Application;
+use OCA\UserOIDC\Db\ProviderMapper;
+use OCA\UserOIDC\Service\ID4MeService;
+use OCP\Authentication\IAlternativeLoginProvider;
+use OCP\IConfig;
+use OCP\IL10N;
+use OCP\IRequest;
+use OCP\IURLGenerator;
+
+class AlternativeLoginProvider implements IAlternativeLoginProvider {
+	public function __construct(
+		private IRequest $request,
+		private IUrlGenerator $urlGenerator,
+		private ProviderMapper $providerMapper,
+		private IConfig $config,
+		private IL10N $l10n,
+		private ID4MeService $id4MeService,
+	) {
+	}
+
+	public function getAlternativeLogin(): array {
+		$alternativeLogins = [];
+		$redirectUrl = $this->request->getParam('redirect_url');
+		$absoluteRedirectUrl = !empty($redirectUrl) ? $this->urlGenerator->getAbsoluteURL($redirectUrl) : $redirectUrl;
+		$providers = $this->providerMapper->getProviders();
+		$customLoginLabel = $this->config->getSystemValue('user_oidc', [])['login_label'] ?? '';
+		foreach ($providers as $provider) {
+			$alternativeLogins[] = new AlternativeLogin(
+				$customLoginLabel
+					? preg_replace('/{name}/', $provider->getIdentifier(), $customLoginLabel)
+					: $this->l10n->t('Login with %1s', [$provider->getIdentifier()]),
+				$this->urlGenerator->linkToRoute(Application::APP_ID . '.login.login', ['providerId' => $provider->getId(), 'redirectUrl' => $absoluteRedirectUrl]),
+			);
+		}
+
+		if ($this->id4MeService->getID4ME()) {
+			$alternativeLogins[] = new AlternativeLogin(
+				'ID4ME',
+				$this->urlGenerator->linkToRoute(Application::APP_ID . '.id4me.login'),
+			);
+		}
+
+		return $alternativeLogins;
+	}
+}

lib/AppInfo/Application.php

@@ -11,6 +11,7 @@
 use Exception;
 use OC_App;
 use OCA\Files\Event\LoadAdditionalScriptsEvent;
+use OCA\UserOIDC\AlternativeLogin\AlternativeLoginProvider;
 use OCA\UserOIDC\Db\ProviderMapper;
 use OCA\UserOIDC\Event\ExchangedTokenRequestedEvent;
 use OCA\UserOIDC\Event\ExternalTokenRequestedEvent;
@@ -70,6 +71,10 @@ public function register(IRegistrationContext $context): void {
 		if (class_exists(\OCP\Authentication\Events\TokenInvalidatedEvent::class)) {
 			$context->registerEventListener(\OCP\Authentication\Events\TokenInvalidatedEvent::class, TokenInvalidatedListener::class);
 		}
+
+		if (version_compare($config->getSystemValueString('version', '0.0.0'), '34.0.0', '>=')) {
+			$context->registerAlternativeLoginProvider(AlternativeLoginProvider::class);
+		}
 	}
 
 	public function boot(IBootContext $context): void {
@@ -83,7 +88,9 @@ public function boot(IBootContext $context): void {
 
 		try {
 			$context->injectFn(\Closure::fromCallable([$this, 'registerRedirect']));
-			$context->injectFn(\Closure::fromCallable([$this, 'registerLogin']));
+			if (version_compare($this->getContainer()->get(IConfig::class)->getSystemValueString('version', '0.0.0'), '34.0.0', '<')) {
+				$context->injectFn(\Closure::fromCallable([$this, 'registerLogin']));
+			}
 		} catch (Throwable $e) {
 		}
 	}
@@ -93,7 +100,6 @@ private function checkLoginToken(TokenService $tokenService): void {
 	}
 
 	private function registerRedirect(IRequest $request, IURLGenerator $urlGenerator, SettingsService $settings, ProviderMapper $providerMapper): void {
-		$providers = $this->getCachedProviders($providerMapper);
 		$redirectUrl = $request->getParam('redirect_url');
 		$absoluteRedirectUrl = !empty($redirectUrl) ? $urlGenerator->getAbsoluteURL($redirectUrl) : $redirectUrl;
 
@@ -104,13 +110,16 @@ private function registerRedirect(IRequest $request, IURLGenerator $urlGenerator
 		} catch (Exception $e) {
 			// in case any errors happen when checking for the path do not apply redirect logic as it is only needed for the login
 		}
-		if ($isDefaultLogin && !$settings->getAllowMultipleUserBackEnds() && count($providers) === 1) {
-			$targetUrl = $urlGenerator->linkToRoute(self::APP_ID . '.login.login', [
-				'providerId' => $providers[0]->getId(),
-				'redirectUrl' => $absoluteRedirectUrl
-			]);
-			header('Location: ' . $targetUrl);
-			exit();
+		if ($isDefaultLogin && !$settings->getAllowMultipleUserBackEnds()) {
+			$providers = $this->getCachedProviders($providerMapper);
+			if (count($providers) === 1) {
+				$targetUrl = $urlGenerator->linkToRoute(self::APP_ID . '.login.login', [
+					'providerId' => $providers[0]->getId(),
+					'redirectUrl' => $absoluteRedirectUrl
+				]);
+				header('Location: ' . $targetUrl);
+				exit();
+			}
 		}
 	}