fix(php8): be compatible

add config to be sure to keep compatible php 7.2.5

composer.json

@@ -31,7 +31,7 @@
         "source": "https://github.com/picocms/Pico"
     },
     "require": {
-        "php": ">=7.2.5",
+        "php": ">=7.2.5||^8.0",
         "ext-mbstring": "*",
         "twig/twig": "^3.3.8",
         "symfony/yaml" : "^5.4.3",
@@ -56,5 +56,15 @@
             "dev-master": "2.1.x-dev",
             "dev-pico-3.0": "3.0.x-dev"
         }
+    },
+    "config": {
+        "platform": {
+            "php": "7.2.5"
+        },
+        "platform-check": true,
+        "sort-packages": true,
+        "allow-plugins": {
+            "picocms/composer-installer": true
+        }
     }
 }

lib/Pico.php

@@ -2147,12 +2147,12 @@ class Pico
         if ($this->twig === null) {
             $twigConfig = $this->getConfig('twig_config');
 
-            $twigLoader = new TwigFilesystemLoader($this->getThemesDir() . $this->getTheme());
-            $this->twig = new TwigEnvironment($twigLoader, $twigConfig);
+            $twigLoader = new \Twig\Loader\FilesystemLoader($this->getThemesDir() . $this->getTheme());
+            $this->twig = new \Twig\Environment($twigLoader, $twigConfig);
             $this->twig->addExtension(new PicoTwigExtension($this));
 
             if (!empty($twigConfig['debug'])) {
-                $this->twig->addExtension(new TwigDebugExtension());
+                $this->twig->addExtension(new Twig\Extension\DebugExtension());
             }
 
             // register content filter
@@ -2160,7 +2160,7 @@ class Pico
             // this is the reason why we can't register this filter as part of PicoTwigExtension
             $pico = $this;
             $pages = &$this->pages;
-            $this->twig->addFilter(new TwigFilter(
+            $this->twig->addFilter(new \Twig\TwigFilter(
                 'content',
                 function ($page) use ($pico, &$pages) {
                     if (isset($pages[$page])) {
@@ -2201,7 +2201,7 @@ class Pico
             'theme_url' => $this->getConfig('themes_url') . $this->getTheme(),
             'site_title' => $this->getConfig('site_title'),
             'meta' => $this->meta,
-            'content' => new TwigMarkup($this->content, 'UTF-8'),
+            'content' => new \Twig\Markup($this->content, 'UTF-8'),
             'pages' => $this->pages,
             'previous_page' => $this->previousPage,
             'current_page' => $this->currentPage,

lib/PicoTwigExtension.php

@@ -75,16 +75,21 @@ class PicoTwigExtension extends AbstractTwigExtension
      *
      * @see TwigExtensionInterface::getFilters()
      *
-     * @return TwigFilter[] array of Pico's Twig filters
+     * @return \Twig\TwigFilter[] array of Pico's Twig filters
      */
     public function getFilters(): array
     {
-        return [
-            'markdown' => new TwigFilter('markdown', [ $this, 'markdownFilter' ], [ 'is_safe' => [ 'html' ] ]),
-            'sort_by' => new TwigFilter('sort_by', [ $this, 'sortByFilter' ]),
-            'link' => new TwigFilter('link', [ $this->pico, 'getPageUrl' ]),
-            'url' => new TwigFilter('url', [ $this->pico, 'substituteUrl' ]),
-        ];
+        return array(
+            'markdown' => new \Twig\TwigFilter(
+                'markdown',
+                array($this, 'markdownFilter'),
+                array('is_safe' => array('html'))
+            ),
+            'map' => new \Twig\TwigFilter('map', array($this, 'mapFilter')),
+            'sort_by' => new \Twig\TwigFilter('sort_by', array($this, 'sortByFilter')),
+            'link' => new \Twig\TwigFilter('link', array($this->pico, 'getPageUrl')),
+            'url' => new \Twig\TwigFilter('url', array($this->pico, 'substituteUrl'))
+        );
     }
 
     /**