12 files changed, 252 insertions, 63 deletions

diff --git a/application/bookmark/BookmarkIO.php b/application/bookmark/BookmarkIO.php
index c78dbe41..8439d470 100644
--- a/application/bookmark/BookmarkIO.php
+++ b/application/bookmark/BookmarkIO.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace Shaarli\Bookmark;
 
+use malkusch\lock\exception\LockAcquireException;
 use malkusch\lock\mutex\Mutex;
 use malkusch\lock\mutex\NoMutex;
 use Shaarli\Bookmark\Exception\DatastoreNotInitializedException;
@@ -80,7 +81,7 @@ class BookmarkIO
         }
 
         $content = null;
-        $this->mutex->synchronized(function () use (&$content) {
+        $this->synchronized(function () use (&$content) {
             $content = file_get_contents($this->datastore);
         });
 
@@ -119,11 +120,28 @@ class BookmarkIO
 
         $data = self::$phpPrefix . base64_encode(gzdeflate(serialize($links))) . self::$phpSuffix;
 
-        $this->mutex->synchronized(function () use ($data) {
+        $this->synchronized(function () use ($data) {
             file_put_contents(
                 $this->datastore,
                 $data
             );
         });
     }
+
+    /**
+     * Wrapper applying mutex to provided function.
+     * If the lock can't be acquired (e.g. some shared hosting provider), we execute the function without mutex.
+     *
+     * @see https://github.com/shaarli/Shaarli/issues/1650
+     *
+     * @param callable $function
+     */
+    protected function synchronized(callable $function): void
+    {
+        try {
+            $this->mutex->synchronized($function);
+        } catch (LockAcquireException $exception) {
+            $function();
+        }
+    }
 }
diff --git a/application/bookmark/LinkUtils.php b/application/bookmark/LinkUtils.php
index d65e97ed..0ab2d213 100644
--- a/application/bookmark/LinkUtils.php
+++ b/application/bookmark/LinkUtils.php
@@ -68,11 +68,13 @@ function html_extract_tag($tag, $html)
     $properties = implode('|', $propertiesKey);
     // We need a OR here to accept either 'property=og:noquote' or 'property="og:unrelated og:my-tag"'
     $orCondition  = '["\']?(?:og:)?' . $tag . '["\']?|["\'][^\'"]*?(?:og:)?' . $tag . '[^\'"]*?[\'"]';
+    // Support quotes in double quoted content, and the other way around
+    $content = 'content=(["\'])((?:(?!\1).)*)\1';
     // Try to retrieve OpenGraph tag.
-    $ogRegex = '#<meta[^>]+(?:' . $properties . ')=(?:' . $orCondition . ')[^>]*content=(["\'])([^\1]*?)\1.*?>#';
+    $ogRegex = '#<meta[^>]+(?:' . $properties . ')=(?:' . $orCondition . ')[^>]*' . $content . '.*?>#';
     // If the attributes are not in the order property => content (e.g. Github)
     // New regex to keep this readable... more or less.
-    $ogRegexReverse = '#<meta[^>]+content=(["\'])([^\1]*?)\1[^>]+(?:' . $properties . ')=(?:' . $orCondition . ').*?>#';
+    $ogRegexReverse = '#<meta[^>]+' . $content . '[^>]+(?:' . $properties . ')=(?:' . $orCondition . ').*?>#';
 
     if (
         preg_match($ogRegex, $html, $matches) > 0
diff --git a/application/container/ContainerBuilder.php b/application/container/ContainerBuilder.php
index f0234eca..6d69a880 100644
--- a/application/container/ContainerBuilder.php
+++ b/application/container/ContainerBuilder.php
@@ -50,6 +50,9 @@ class ContainerBuilder
     /** @var LoginManager */
     protected $login;
 
+    /** @var PluginManager */
+    protected $pluginManager;
+
     /** @var LoggerInterface */
     protected $logger;
 
@@ -61,12 +64,14 @@ class ContainerBuilder
         SessionManager $session,
         CookieManager $cookieManager,
         LoginManager $login,
+        PluginManager $pluginManager,
         LoggerInterface $logger
     ) {
         $this->conf = $conf;
         $this->session = $session;
         $this->login = $login;
         $this->cookieManager = $cookieManager;
+        $this->pluginManager = $pluginManager;
         $this->logger = $logger;
     }
 
@@ -78,12 +83,10 @@ class ContainerBuilder
         $container['sessionManager'] = $this->session;
         $container['cookieManager'] = $this->cookieManager;
         $container['loginManager'] = $this->login;
+        $container['pluginManager'] = $this->pluginManager;
         $container['logger'] = $this->logger;
         $container['basePath'] = $this->basePath;
 
-        $container['plugins'] = function (ShaarliContainer $container): PluginManager {
-            return new PluginManager($container->conf);
-        };
 
         $container['history'] = function (ShaarliContainer $container): History {
             return new History($container->conf->get('resource.history'));
@@ -113,14 +116,6 @@ class ContainerBuilder
             );
         };
 
-        $container['pluginManager'] = function (ShaarliContainer $container): PluginManager {
-            $pluginManager = new PluginManager($container->conf);
-
-            $pluginManager->load($container->conf->get('general.enabled_plugins'));
-
-            return $pluginManager;
-        };
-
         $container['formatterFactory'] = function (ShaarliContainer $container): FormatterFactory {
             return new FormatterFactory(
                 $container->conf,
diff --git a/application/feed/CachedPage.php b/application/feed/CachedPage.php
index d809bdd9..c23c200f 100644
--- a/application/feed/CachedPage.php
+++ b/application/feed/CachedPage.php
@@ -1,34 +1,43 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Shaarli\Feed;
 
+use DatePeriod;
+
 /**
  * Simple cache system, mainly for the RSS/ATOM feeds
  */
 class CachedPage
 {
-    // Directory containing page caches
-    private $cacheDir;
+    /** Directory containing page caches */
+    protected $cacheDir;
+
+    /** Should this URL be cached (boolean)? */
+    protected $shouldBeCached;
 
-    // Should this URL be cached (boolean)?
-    private $shouldBeCached;
+    /** Name of the cache file for this URL */
+    protected $filename;
 
-    // Name of the cache file for this URL
-    private $filename;
+    /** @var DatePeriod|null Optionally specify a period of time for cache validity */
+    protected $validityPeriod;
 
     /**
      * Creates a new CachedPage
      *
-     * @param string $cacheDir       page cache directory
-     * @param string $url            page URL
-     * @param bool   $shouldBeCached whether this page needs to be cached
+     * @param string      $cacheDir       page cache directory
+     * @param string      $url            page URL
+     * @param bool        $shouldBeCached whether this page needs to be cached
+     * @param ?DatePeriod $validityPeriod Optionally specify a time limit on requested cache
      */
-    public function __construct($cacheDir, $url, $shouldBeCached)
+    public function __construct($cacheDir, $url, $shouldBeCached, ?DatePeriod $validityPeriod)
     {
         // TODO: check write access to the cache directory
         $this->cacheDir = $cacheDir;
         $this->filename = $this->cacheDir . '/' . sha1($url) . '.cache';
         $this->shouldBeCached = $shouldBeCached;
+        $this->validityPeriod = $validityPeriod;
     }
 
     /**
@@ -41,10 +50,20 @@ class CachedPage
         if (!$this->shouldBeCached) {
             return null;
         }
-        if (is_file($this->filename)) {
-            return file_get_contents($this->filename);
+        if (!is_file($this->filename)) {
+            return null;
+        }
+        if ($this->validityPeriod !== null) {
+            $cacheDate = \DateTime::createFromFormat('U', (string) filemtime($this->filename));
+            if (
+                $cacheDate < $this->validityPeriod->getStartDate()
+                || $cacheDate > $this->validityPeriod->getEndDate()
+            ) {
+                return null;
+            }
         }
-        return null;
+
+        return file_get_contents($this->filename);
     }
 
     /**
diff --git a/application/front/controller/admin/ServerController.php b/application/front/controller/admin/ServerController.php
index fabeaf2f..4b74f4a9 100644
--- a/application/front/controller/admin/ServerController.php
+++ b/application/front/controller/admin/ServerController.php
@@ -39,11 +39,16 @@ class ServerController extends ShaarliAdminController
         $currentVersion = $currentVersion === 'dev' ? $currentVersion : 'v' . $currentVersion;
         $phpEol = new \DateTimeImmutable(ApplicationUtils::getPhpEol(PHP_VERSION));
 
+        $permissions = array_merge(
+            ApplicationUtils::checkResourcePermissions($this->container->conf),
+            ApplicationUtils::checkDatastoreMutex()
+        );
+
         $this->assignView('php_version', PHP_VERSION);
         $this->assignView('php_eol', format_date($phpEol, false));
         $this->assignView('php_has_reached_eol', $phpEol < new \DateTimeImmutable());
         $this->assignView('php_extensions', ApplicationUtils::getPhpExtensionsRequirement());
-        $this->assignView('permissions', ApplicationUtils::checkResourcePermissions($this->container->conf));
+        $this->assignView('permissions', $permissions);
         $this->assignView('release_url', $releaseUrl);
         $this->assignView('latest_version', $latestVersion);
         $this->assignView('current_version', $currentVersion);
diff --git a/application/front/controller/visitor/DailyController.php b/application/front/controller/visitor/DailyController.php
index 846cfe22..29492a5f 100644
--- a/application/front/controller/visitor/DailyController.php
+++ b/application/front/controller/visitor/DailyController.php
@@ -86,9 +86,11 @@ class DailyController extends ShaarliVisitorController
     public function rss(Request $request, Response $response): Response
     {
         $response = $response->withHeader('Content-Type', 'application/rss+xml; charset=utf-8');
+        $type = DailyPageHelper::extractRequestedType($request);
+        $cacheDuration = DailyPageHelper::getCacheDatePeriodByType($type);
 
         $pageUrl = page_url($this->container->environment);
-        $cache = $this->container->pageCacheManager->getCachePage($pageUrl);
+        $cache = $this->container->pageCacheManager->getCachePage($pageUrl, $cacheDuration);
 
         $cached = $cache->cachedVersion();
         if (!empty($cached)) {
@@ -96,7 +98,6 @@ class DailyController extends ShaarliVisitorController
         }
 
         $days = [];
-        $type = DailyPageHelper::extractRequestedType($request);
         $format = DailyPageHelper::getFormatByType($type);
         $length = DailyPageHelper::getRssLengthByType($type);
         foreach ($this->container->bookmarkService->search() as $bookmark) {
@@ -131,7 +132,7 @@ class DailyController extends ShaarliVisitorController
             $dataPerDay[$day] = [
                 'date' => $endDateTime,
                 'date_rss' => $endDateTime->format(DateTime::RSS),
-                'date_human' => DailyPageHelper::getDescriptionByType($type, $dayDateTime),
+                'date_human' => DailyPageHelper::getDescriptionByType($type, $dayDateTime, false),
                 'absolute_url' => $indexUrl . 'daily?' . $type . '=' . $day,
                 'links' => [],
             ];
diff --git a/application/front/controller/visitor/InstallController.php b/application/front/controller/visitor/InstallController.php
index bf965929..418d4a49 100644
--- a/application/front/controller/visitor/InstallController.php
+++ b/application/front/controller/visitor/InstallController.php
@@ -56,11 +56,16 @@ class InstallController extends ShaarliVisitorController
 
         $phpEol = new \DateTimeImmutable(ApplicationUtils::getPhpEol(PHP_VERSION));
 
+        $permissions = array_merge(
+            ApplicationUtils::checkResourcePermissions($this->container->conf),
+            ApplicationUtils::checkDatastoreMutex()
+        );
+
         $this->assignView('php_version', PHP_VERSION);
         $this->assignView('php_eol', format_date($phpEol, false));
         $this->assignView('php_has_reached_eol', $phpEol < new \DateTimeImmutable());
         $this->assignView('php_extensions', ApplicationUtils::getPhpExtensionsRequirement());
-        $this->assignView('permissions', ApplicationUtils::checkResourcePermissions($this->container->conf));
+        $this->assignView('permissions', $permissions);
 
         $this->assignView('pagetitle', t('Install Shaarli'));
 
diff --git a/application/helper/ApplicationUtils.php b/application/helper/ApplicationUtils.php
index 212dd8e2..a6c03aae 100644
--- a/application/helper/ApplicationUtils.php
+++ b/application/helper/ApplicationUtils.php
@@ -3,6 +3,8 @@
 namespace Shaarli\Helper;
 
 use Exception;
+use malkusch\lock\exception\LockAcquireException;
+use malkusch\lock\mutex\FlockMutex;
 use Shaarli\Config\ConfigManager;
 
 /**
@@ -252,6 +254,20 @@ class ApplicationUtils
         return $errors;
     }
 
+    public static function checkDatastoreMutex(): array
+    {
+        $mutex = new FlockMutex(fopen(SHAARLI_MUTEX_FILE, 'r'), 2);
+        try {
+            $mutex->synchronized(function () {
+                return true;
+            });
+        } catch (LockAcquireException $e) {
+            $errors[] = t('Lock can not be acquired on the datastore. You might encounter concurrent access issues.');
+        }
+
+        return $errors ?? [];
+    }
+
     /**
      * Returns a salted hash representing the current Shaarli version.
      *
diff --git a/application/helper/DailyPageHelper.php b/application/helper/DailyPageHelper.php
index 5fabc907..05f95812 100644
--- a/application/helper/DailyPageHelper.php
+++ b/application/helper/DailyPageHelper.php
@@ -4,6 +4,9 @@ declare(strict_types=1);
 
 namespace Shaarli\Helper;
 
+use DatePeriod;
+use DateTimeImmutable;
+use Exception;
 use Shaarli\Bookmark\Bookmark;
 use Slim\Http\Request;
 
@@ -40,31 +43,31 @@ class DailyPageHelper
      * @param string|null   $requestedDate  Input string extracted from the request
      * @param Bookmark|null $latestBookmark Latest bookmark found in the datastore (by date)
      *
-     * @return \DateTimeImmutable from input or latest bookmark.
+     * @return DateTimeImmutable from input or latest bookmark.
      *
-     * @throws \Exception Type not supported.
+     * @throws Exception Type not supported.
      */
     public static function extractRequestedDateTime(
         string $type,
         ?string $requestedDate,
         Bookmark $latestBookmark = null
-    ): \DateTimeImmutable {
+    ): DateTimeImmutable {
         $format = static::getFormatByType($type);
         if (empty($requestedDate)) {
             return $latestBookmark instanceof Bookmark
-                ? new \DateTimeImmutable($latestBookmark->getCreated()->format(\DateTime::ATOM))
-                : new \DateTimeImmutable()
+                ? new DateTimeImmutable($latestBookmark->getCreated()->format(\DateTime::ATOM))
+                : new DateTimeImmutable()
             ;
         }
 
         // W is not supported by createFromFormat...
         if ($type === static::WEEK) {
-            return (new \DateTimeImmutable())
+            return (new DateTimeImmutable())
                 ->setISODate((int) substr($requestedDate, 0, 4), (int) substr($requestedDate, 4, 2))
             ;
         }
 
-        return \DateTimeImmutable::createFromFormat($format, $requestedDate);
+        return DateTimeImmutable::createFromFormat($format, $requestedDate);
     }
 
     /**
@@ -80,7 +83,7 @@ class DailyPageHelper
      *
      * @see https://www.php.net/manual/en/datetime.format.php
      *
-     * @throws \Exception Type not supported.
+     * @throws Exception Type not supported.
      */
     public static function getFormatByType(string $type): string
     {
@@ -92,7 +95,7 @@ class DailyPageHelper
             case static::DAY:
                 return 'Ymd';
             default:
-                throw new \Exception('Unsupported daily format type');
+                throw new Exception('Unsupported daily format type');
         }
     }
 
@@ -102,14 +105,14 @@ class DailyPageHelper
      *       and we don't want to alter original datetime.
      *
      * @param string             $type      month/week/day
-     * @param \DateTimeImmutable $requested DateTime extracted from request input
+     * @param DateTimeImmutable $requested DateTime extracted from request input
      *                                      (should come from extractRequestedDateTime)
      *
      * @return \DateTimeInterface First DateTime of the time period
      *
-     * @throws \Exception Type not supported.
+     * @throws Exception Type not supported.
      */
-    public static function getStartDateTimeByType(string $type, \DateTimeImmutable $requested): \DateTimeInterface
+    public static function getStartDateTimeByType(string $type, DateTimeImmutable $requested): \DateTimeInterface
     {
         switch ($type) {
             case static::MONTH:
@@ -119,7 +122,7 @@ class DailyPageHelper
             case static::DAY:
                 return $requested->modify('Today midnight');
             default:
-                throw new \Exception('Unsupported daily format type');
+                throw new Exception('Unsupported daily format type');
         }
     }
 
@@ -129,14 +132,14 @@ class DailyPageHelper
      *       and we don't want to alter original datetime.
      *
      * @param string             $type      month/week/day
-     * @param \DateTimeImmutable $requested DateTime extracted from request input
+     * @param DateTimeImmutable $requested DateTime extracted from request input
      *                                      (should come from extractRequestedDateTime)
      *
      * @return \DateTimeInterface Last DateTime of the time period
      *
-     * @throws \Exception Type not supported.
+     * @throws Exception Type not supported.
      */
-    public static function getEndDateTimeByType(string $type, \DateTimeImmutable $requested): \DateTimeInterface
+    public static function getEndDateTimeByType(string $type, DateTimeImmutable $requested): \DateTimeInterface
     {
         switch ($type) {
             case static::MONTH:
@@ -146,7 +149,7 @@ class DailyPageHelper
             case static::DAY:
                 return $requested->modify('Today 23:59:59');
             default:
-                throw new \Exception('Unsupported daily format type');
+                throw new Exception('Unsupported daily format type');
         }
     }
 
@@ -154,16 +157,20 @@ class DailyPageHelper
      * Get localized description of the time period depending on given datetime and type.
      * Example: for a month period, it returns `October, 2020`.
      *
-     * @param string             $type      month/week/day
-     * @param \DateTimeImmutable $requested DateTime extracted from request input
-     *                                      (should come from extractRequestedDateTime)
+     * @param string             $type            month/week/day
+     * @param \DateTimeImmutable $requested       DateTime extracted from request input
+     *                                            (should come from extractRequestedDateTime)
+     * @param bool               $includeRelative Include relative date description (today, yesterday, etc.)
      *
      * @return string Localized time period description
      *
-     * @throws \Exception Type not supported.
+     * @throws Exception Type not supported.
      */
-    public static function getDescriptionByType(string $type, \DateTimeImmutable $requested): string
-    {
+    public static function getDescriptionByType(
+        string $type,
+        \DateTimeImmutable $requested,
+        bool $includeRelative = true
+    ): string {
         switch ($type) {
             case static::MONTH:
                 return $requested->format('F') . ', ' . $requested->format('Y');
@@ -172,14 +179,14 @@ class DailyPageHelper
                 return t('Week') . ' ' . $requested->format('W') . ' (' . format_date($requested, false) . ')';
             case static::DAY:
                 $out = '';
-                if ($requested->format('Ymd') === date('Ymd')) {
+                if ($includeRelative && $requested->format('Ymd') === date('Ymd')) {
                     $out = t('Today') . ' - ';
-                } elseif ($requested->format('Ymd') === date('Ymd', strtotime('-1 days'))) {
+                } elseif ($includeRelative && $requested->format('Ymd') === date('Ymd', strtotime('-1 days'))) {
                     $out = t('Yesterday') . ' - ';
                 }
                 return $out . format_date($requested, false);
             default:
-                throw new \Exception('Unsupported daily format type');
+                throw new Exception('Unsupported daily format type');
         }
     }
 
@@ -190,7 +197,7 @@ class DailyPageHelper
      *
      * @return int number of elements
      *
-     * @throws \Exception Type not supported.
+     * @throws Exception Type not supported.
      */
     public static function getRssLengthByType(string $type): int
     {
@@ -202,7 +209,28 @@ class DailyPageHelper
             case static::DAY:
                 return 30; // ~1 month
             default:
-                throw new \Exception('Unsupported daily format type');
+                throw new Exception('Unsupported daily format type');
         }
     }
+
+    /**
+     * Get the number of items to display in the RSS feed depending on the given type.
+     *
+     * @param string             $type      month/week/day
+     * @param ?DateTimeImmutable $requested Currently only used for UT
+     *
+     * @return DatePeriod number of elements
+     *
+     * @throws Exception Type not supported.
+     */
+    public static function getCacheDatePeriodByType(string $type, DateTimeImmutable $requested = null): DatePeriod
+    {
+        $requested = $requested ?? new DateTimeImmutable();
+
+        return new DatePeriod(
+            static::getStartDateTimeByType($type, $requested),
+            new \DateInterval('P1D'),
+            static::getEndDateTimeByType($type, $requested)
+        );
+    }
 }
diff --git a/application/plugin/PluginManager.php b/application/plugin/PluginManager.php
index 3ea55728..7fc0cb04 100644
--- a/application/plugin/PluginManager.php
+++ b/application/plugin/PluginManager.php
@@ -4,6 +4,7 @@ namespace Shaarli\Plugin;
 
 use Shaarli\Config\ConfigManager;
 use Shaarli\Plugin\Exception\PluginFileNotFoundException;
+use Shaarli\Plugin\Exception\PluginInvalidRouteException;
 
 /**
  * Class PluginManager
@@ -26,6 +27,14 @@ class PluginManager
      */
     private $loadedPlugins = [];
 
+    /** @var array List of registered routes. Contains keys:
+     *               - `method`: HTTP method, GET/POST/PUT/PATCH/DELETE
+     *               - `route` (path): without prefix, e.g. `/up/{variable}`
+     *                 It will be later prefixed by `/plugin/<plugin name>/`.
+     *               - `callable` string, function name or FQN class's method, e.g. `demo_plugin_custom_controller`.
+     */
+    protected $registeredRoutes = [];
+
     /**
      * @var ConfigManager Configuration Manager instance.
      */
@@ -86,6 +95,9 @@ class PluginManager
                 $this->loadPlugin($dirs[$index], $plugin);
             } catch (PluginFileNotFoundException $e) {
                 error_log($e->getMessage());
+            } catch (\Throwable $e) {
+                $error = $plugin . t(' [plugin incompatibility]: ') . $e->getMessage();
+                $this->errors = array_unique(array_merge($this->errors, [$error]));
             }
         }
     }
@@ -166,6 +178,22 @@ class PluginManager
             }
         }
 
+        $registerRouteFunction = $pluginName . '_register_routes';
+        $routes = null;
+        if (function_exists($registerRouteFunction)) {
+            $routes = call_user_func($registerRouteFunction);
+        }
+
+        if ($routes !== null) {
+            foreach ($routes as $route) {
+                if (static::validateRouteRegistration($route)) {
+                    $this->registeredRoutes[$pluginName][] = $route;
+                } else {
+                    throw new PluginInvalidRouteException($pluginName);
+                }
+            }
+        }
+
         $this->loadedPlugins[] = $pluginName;
     }
 
@@ -238,6 +266,14 @@ class PluginManager
     }
 
     /**
+     * @return array List of registered custom routes by plugins.
+     */
+    public function getRegisteredRoutes(): array
+    {
+        return $this->registeredRoutes;
+    }
+
+    /**
      * Return the list of encountered errors.
      *
      * @return array List of errors (empty array if none exists).
@@ -246,4 +282,32 @@ class PluginManager
     {
         return $this->errors;
     }
+
+    /**
+     * Checks whether provided input is valid to register a new route.
+     * It must contain keys `method`, `route`, `callable` (all strings).
+     *
+     * @param string[] $input
+     *
+     * @return bool
+     */
+    protected static function validateRouteRegistration(array $input): bool
+    {
+        if (
+            !array_key_exists('method', $input)
+            || !in_array(strtoupper($input['method']), ['GET', 'PUT', 'PATCH', 'POST', 'DELETE'])
+        ) {
+            return false;
+        }
+
+        if (!array_key_exists('route', $input) || !preg_match('#^[a-z\d/\.\-_]+$#', $input['route'])) {
+            return false;
+        }
+
+        if (!array_key_exists('callable', $input)) {
+            return false;
+        }
+
+        return true;
+    }
 }
diff --git a/application/plugin/exception/PluginInvalidRouteException.php b/application/plugin/exception/PluginInvalidRouteException.php
new file mode 100644
index 00000000..6ba9bc43
--- /dev/null
+++ b/application/plugin/exception/PluginInvalidRouteException.php
@@ -0,0 +1,26 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Shaarli\Plugin\Exception;
+
+use Exception;
+
+/**
+ * Class PluginFileNotFoundException
+ *
+ * Raise when plugin files can't be found.
+ */
+class PluginInvalidRouteException extends Exception
+{
+    /**
+     * Construct exception with plugin name.
+     * Generate message.
+     *
+     * @param string $pluginName name of the plugin not found
+     */
+    public function __construct()
+    {
+        $this->message = 'trying to register invalid route.';
+    }
+}
diff --git a/application/render/PageCacheManager.php b/application/render/PageCacheManager.php
index 97805c35..fe74bf27 100644
--- a/application/render/PageCacheManager.php
+++ b/application/render/PageCacheManager.php
@@ -2,6 +2,7 @@
 
 namespace Shaarli\Render;
 
+use DatePeriod;
 use Shaarli\Feed\CachedPage;
 
 /**
@@ -49,12 +50,21 @@ class PageCacheManager
         $this->purgeCachedPages();
     }
 
-    public function getCachePage(string $pageUrl): CachedPage
+    /**
+     * Get CachedPage instance for provided URL.
+     *
+     * @param string      $pageUrl
+     * @param ?DatePeriod $validityPeriod Optionally specify a time limit on requested cache
+     *
+     * @return CachedPage
+     */
+    public function getCachePage(string $pageUrl, DatePeriod $validityPeriod = null): CachedPage
     {
         return new CachedPage(
             $this->pageCacheDir,
             $pageUrl,
-            false === $this->isLoggedIn
+            false === $this->isLoggedIn,
+            $validityPeriod
         );
     }
 }