feat: Upgrade Pico to PHP 8.2/8.3

Make Pico compatible with PHP 8.2 and 8.3.

- Upgrade symfony/yaml config reader
- Upgrade twig template engine,
- Raise supported PHP version,
- Remove pico/pico-deprecated
- Remove redundant index files
- Use pico-composer to set up a project

Required Changes for users running version 2.1:

- Replace composer.json from pico/pico-composer to load Pico Core via Composer
- Add all required folders to project root (config/, plugins/, themes/)
- Convert config file from PHP to YAML
  - Errors may happen due to wrong value types (eg. multiline text is not supported)
- Themes may need some tweaks:
  - Themes need a YAML config as well
  - HTML files in themes need to be renamed to TWIG files
  - Replace twig condition »is_front_page« with »current_page.id == "index"«
  - Replace twig variable »page.excerpt« with »page.meta.Summary«

Author: pixelbrackets

composer.json

@@ -31,16 +31,15 @@
         "source": "https://github.com/picocms/Pico"
     },
     "require": {
-        "php": ">=5.3.6",
+        "php": ">=8.2.20",
         "ext-mbstring": "*",
-        "twig/twig": "^1.36",
-        "symfony/yaml" : "^2.8",
+        "twig/twig": "^3.14",
+        "symfony/yaml" : "^7.1",
         "erusev/parsedown": "1.8.0-beta-7",
         "erusev/parsedown-extra": "0.8.0-beta-1"
     },
     "suggest": {
         "picocms/pico-theme": "Pico requires a theme to actually display the contents of your website. This is Pico's official default theme.",
-        "picocms/pico-deprecated": "PicoDeprecated's purpose is to maintain backward compatibility to older versions of Pico.",
         "picocms/composer-installer": "This Composer plugin is responsible for installing Pico plugins and themes using the Composer package manager."
     },
     "autoload": {
@@ -49,11 +48,5 @@
             "PicoPluginInterface": "lib/",
             "AbstractPicoPlugin": "lib/"
         }
-    },
-    "extra": {
-        "branch-alias": {
-            "dev-master": "2.1.x-dev",
-            "dev-pico-3.0": "3.0.x-dev"
-        }
     }
 }

lib/Pico.php

@@ -307,7 +307,7 @@ class Pico
      * Twig instance used for template parsing
      *
      * @see Pico::getTwig()
-     * @var Twig_Environment|null
+     * @var \TwigEnvironment|null
      */
     protected $twig;
 
@@ -2095,27 +2095,27 @@ public function getPageTree()
      * @see https://twig.symfony.com/ Twig website
      * @see https://github.com/twigphp/Twig Twig on GitHub
      *
-     * @return Twig_Environment|null Twig template engine
+     * @return \TwigEnvironment|null Twig template engine
      */
     public function getTwig()
     {
         if ($this->twig === null) {
             $twigConfig = $this->getConfig('twig_config');
 
-            $twigLoader = new Twig_Loader_Filesystem($this->getThemesDir() . $this->getTheme());
-            $this->twig = new Twig_Environment($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 Twig_Extension_Debug());
+                $this->twig->addExtension(new \Twig\Extension\DebugExtension());
             }
 
             // register content filter
             // we pass the $pages array by reference to prevent multiple parser runs for the same page
             // this is the reason why we can't register this filter as part of PicoTwigExtension
             $pico = $this;
             $pages = &$this->pages;
-            $this->twig->addFilter(new Twig_SimpleFilter(
+            $this->twig->addFilter(new \Twig\TwigFilter(
                 'content',
                 function ($page) use ($pico, &$pages) {
                     if (isset($pages[$page])) {
@@ -2156,7 +2156,7 @@ protected function getTwigVariables()
             'theme_url' => $this->getConfig('themes_url') . $this->getTheme(),
             'site_title' => $this->getConfig('site_title'),
             'meta' => $this->meta,
-            'content' => new Twig_Markup($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

@@ -18,7 +18,7 @@
  * @license http://opensource.org/licenses/MIT The MIT License
  * @version 2.1
  */
-class PicoTwigExtension extends Twig_Extension
+class PicoTwigExtension extends \Twig\Extension\AbstractExtension
 {
     /**
      * Current instance of Pico
@@ -53,7 +53,7 @@ public function getPico()
     /**
      * Returns the name of the extension
      *
-     * @see Twig_ExtensionInterface::getName()
+     * @see \Twig\Extension\AbstractExtension::getName()
      *
      * @return string the extension name
      */
@@ -65,38 +65,38 @@ public function getName()
     /**
      * Returns a list of Pico-specific Twig filters
      *
-     * @see Twig_ExtensionInterface::getFilters()
+     * @see \Twig\Extension\ExtensionInterface::getFilters()
      *
-     * @return Twig_SimpleFilter[] array of Pico's Twig filters
+     * @return \Twig\TwigFilter[] array of Pico's Twig filters
      */
     public function getFilters()
     {
         return array(
-            'markdown' => new Twig_SimpleFilter(
+            'markdown' => new \Twig\TwigFilter(
                 'markdown',
                 array($this, 'markdownFilter'),
                 array('is_safe' => array('html'))
             ),
-            'map' => new Twig_SimpleFilter('map', array($this, 'mapFilter')),
-            'sort_by' => new Twig_SimpleFilter('sort_by', array($this, 'sortByFilter')),
-            'link' => new Twig_SimpleFilter('link', array($this->pico, 'getPageUrl')),
-            'url' => new Twig_SimpleFilter('url', array($this->pico, 'substituteUrl'))
+            'map' => new \Twig\TwigFilter('map', array($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'))
         );
     }
 
     /**
      * Returns a list of Pico-specific Twig functions
      *
-     * @see Twig_ExtensionInterface::getFunctions()
+     * @see \Twig\Extension\ExtensionInterface::getFunctions()
      *
-     * @return Twig_SimpleFunction[] array of Pico's Twig functions
+     * @return \Twig\TwigFunction[] array of Pico's Twig functions
      */
     public function getFunctions()
     {
         return array(
-            'url_param' => new Twig_SimpleFunction('url_param', array($this, 'urlParamFunction')),
-            'form_param' => new Twig_SimpleFunction('form_param', array($this, 'formParamFunction')),
-            'pages' => new Twig_SimpleFunction('pages', array($this, 'pagesFunction'))
+            'url_param' => new \Twig\TwigFunction('url_param', array($this, 'urlParamFunction')),
+            'form_param' => new \Twig\TwigFunction('form_param', array($this, 'formParamFunction')),
+            'pages' => new \Twig\TwigFunction('pages', array($this, 'pagesFunction'))
         );
     }
 
@@ -136,12 +136,12 @@ public function markdownFilter($markdown, array $meta = array(), $singleLine = f
      *
      * @return array mapped values
      *
-     * @throws Twig_Error_Runtime
+     * @throws \Twig\Error\RuntimeError
      */
     public function mapFilter($var, $mapKeyPath)
     {
         if (!is_array($var) && (!is_object($var) || !($var instanceof Traversable))) {
-            throw new Twig_Error_Runtime(sprintf(
+            throw new \Twig\Error\RuntimeError(sprintf(
                 'The map filter only works with arrays or "Traversable", got "%s"',
                 is_object($var) ? get_class($var) : gettype($var)
             ));
@@ -178,20 +178,20 @@ public function mapFilter($var, $mapKeyPath)
      *
      * @return array sorted array
      *
-     * @throws Twig_Error_Runtime
+     * @throws \Twig\Error\RuntimeError
      */
     public function sortByFilter($var, $sortKeyPath, $fallback = 'bottom')
     {
         if (is_object($var) && ($var instanceof Traversable)) {
             $var = iterator_to_array($var, true);
         } elseif (!is_array($var)) {
-            throw new Twig_Error_Runtime(sprintf(
+            throw new \Twig\Error\RuntimeError(sprintf(
                 'The sort_by filter only works with arrays or "Traversable", got "%s"',
                 is_object($var) ? get_class($var) : gettype($var)
             ));
         }
         if (($fallback !== 'top') && ($fallback !== 'bottom') && ($fallback !== 'keep') && ($fallback !== "remove")) {
-            throw new Twig_Error_Runtime(
+            throw new \Twig\Error\RuntimeError(
                 'The sort_by filter only supports the "top", "bottom", "keep" and "remove" fallbacks'
             );
         }
@@ -399,7 +399,7 @@ public function formParamFunction($name, $filter = '', $options = null, $flags =
      * returns Pico's full pages array.
      *
      * If `$depth` is negative after taking `$offset` into consideration, the
-     * function will throw a {@see Twig_Error_Runtime} exception, since this
+     * function will throw a {@see \Twig\Error\RuntimeError} exception, since this
      * would simply make no sense and is likely an error. Passing a negative
      * `$depthOffset` is equivalent to passing `$depthOffset = 0`.
      *
@@ -421,7 +421,7 @@ public function formParamFunction($name, $filter = '', $options = null, $flags =
      *
      * @return array[] the data of the matched pages
      *
-     * @throws Twig_Error_Runtime
+     * @throws \Twig\Error\RuntimeError
      */
     public function pagesFunction($start = '', $depth = 0, $depthOffset = 0, $offset = 1)
     {
@@ -443,7 +443,7 @@ public function pagesFunction($start = '', $depth = 0, $depthOffset = 0, $offset
         $depthOffset = $depthOffset + $offset;
 
         if (($depth !== null) && ($depth < 0)) {
-            throw new Twig_Error_Runtime('The pages function doesn\'t support negative depths');
+            throw new \Twig\Error\RuntimeError('The pages function doesn\'t support negative depths');
         }
 
         $pageTree = $this->getPico()->getPageTree();