Added translation Twig function and filter

system/src/Grav/Common/Language.php

@@ -2,52 +2,110 @@
 namespace Grav\Common;
 
 /**
- * Contain some useful language functions
+ * Language and translation functionality for Grav
  */
 class Language
 {
+    protected $enabled = true;
     protected $languages = [];
     protected $page_extensions = [];
+    protected $fallback_languages = [];
     protected $default;
     protected $active;
-    protected $enabled = true;
+    protected $config;
 
+    /**
+     * Constructor
+     *
+     * @param \Grav\Common\Grav $grav
+     */
     public function __construct(Grav $grav)
     {
-        $this->languages = $grav['config']->get('system.languages.supported', []);
+        $this->config = $grav['config'];
+        $this->languages = $this->config->get('system.languages.supported', []);
+        $this->init();
+    }
+
+    /**
+     * Initialize the default and enabled languages
+     */
+    public function init()
+    {
         $this->default = reset($this->languages);
 
         if (empty($this->languages)) {
             $this->enabled = false;
         }
-
     }
 
+    /**
+     * Ensure that languages are enabled
+     *
+     * @return bool
+     */
     public function enabled()
     {
         return $this->enabled;
     }
 
+    /**
+     * Gets the array of supported languages
+     *
+     * @return array
+     */
     public function getLanguages()
     {
         return $this->languages;
     }
 
+    /**
+     * Sets the current supported languages manually
+     *
+     * @param $langs
+     */
     public function setLanguages($langs)
     {
         $this->languages = $langs;
+        $this->init();
     }
 
+    /**
+     * Gets a pipe-separated string of available languages
+     *
+     * @return string
+     */
     public function getAvailable()
     {
         return implode('|', $this->languages);
     }
 
+    /**
+     * Gets language, active if set, else default
+     *
+     * @return mixed
+     */
+    public function getLanguage()
+    {
+        return $this->active ? $this->active : $this->default;
+    }
+
+    /**
+     * Gets current default language
+     *
+     * @return mixed
+     */
     public function getDefault()
     {
         return $this->default;
     }
 
+    /**
+     * Sets default language manually
+     *
+     * @param $lang
+     *
+     * @return bool
+     */
     public function setDefault($lang)
     {
         if ($this->validate($lang)) {
@@ -57,11 +115,23 @@ class Language
         return false;
     }
 
+    /**
+     * Gets current active language
+     *
+     * @return mixed
+     */
     public function getActive()
     {
         return $this->active;
     }
 
+    /**
+     * Sets active language manually
+     *
+     * @param $lang
+     *
+     * @return bool
+     */
     public function setActive($lang)
     {
         if ($this->validate($lang)) {
@@ -71,6 +141,13 @@ class Language
         return false;
     }
 
+    /**
+     * Sets the active language based on the first part of the URL
+     *
+     * @param $uri
+     *
+     * @return mixed
+     */
     public function setActiveFromUri($uri)
     {
         $regex = '/(\/('.$this->getAvailable().')).*/';
@@ -87,30 +164,70 @@ class Language
         return $uri;
     }
 
-    public function getValidPageExtensions()
+
+    /**
+     * Gets an array of valid extensions with active first, then fallback extensions
+     *
+     * @return array
+     */
+    public function getFallbackPageExtensions($file_ext = null)
     {
         if (empty($this->page_extensions)) {
+            if (empty($file_ext)) {
+                $file_ext = CONTENT_EXT;
+            }
+
             if ($this->enabled()) {
                 $valid_lang_extensions = [];
                 foreach ($this->languages as $lang) {
-                    $valid_lang_extensions[] = '.'.$lang.CONTENT_EXT;
+                    $valid_lang_extensions[] = '.'.$lang.$file_ext;
                 }
 
                 if ($this->active) {
-                    $active_extension = '.'.$this->active.CONTENT_EXT;
+                    $active_extension = '.'.$this->active.$file_ext;
                     $key = array_search($active_extension, $valid_lang_extensions);
                     unset($valid_lang_extensions[$key]);
                     array_unshift($valid_lang_extensions, $active_extension);
                 }
 
-                $this->page_extensions = array_merge($valid_lang_extensions, (array) CONTENT_EXT);
+                $this->page_extensions = array_merge($valid_lang_extensions, (array) $file_ext);
             } else {
-                $this->page_extensions = (array) CONTENT_EXT;
+                $this->page_extensions = (array) $file_ext;
             }
         }
         return $this->page_extensions;
     }
 
+    /**
+     * Gets an array of languages with active first, then fallback languages
+     *
+     * @return array
+     */
+    public function getFallbackLanguages()
+    {
+        if (empty($this->fallback_languages)) {
+            if ($this->enabled()) {
+                $fallback_languages = $this->languages;
+
+                if ($this->active) {
+                    $active_extension = $this->active;
+                    $key = array_search($active_extension, $fallback_languages);
+                    unset($fallback_languages[$key]);
+                    array_unshift($fallback_languages, $active_extension);
+                }
+                $this->fallback_languages = $fallback_languages;
+            }
+        }
+        return $this->fallback_languages;
+    }
+
+    /**
+     * Ensures the language is valid and supported
+     *
+     * @param $lang
+     *
+     * @return bool
+     */
     public function validate($lang)
     {
         if (in_array($lang, $this->languages)) {
@@ -119,4 +236,42 @@ class Language
         return false;
     }
 
+    /**
+     * Translate a key and possibly arguments into a string using current lang and fallbacks
+     *
+     * @param Array $args     first argument is the lookup key value
+     *                  other arguments can be passed and replaced in the translation with sprintf syntax
+     * @return string
+     */
+    public function translate(Array $args)
+    {
+        $lookup = array_shift($args);
+
+        if ($this->enabled() && $lookup) {
+            foreach ($this->getFallbackLanguages() as $lang) {
+                $translation = $this->getTranslation($lang, $lookup);
+
+                if ($translation) {
+                    if (count($args) >= 1) {
+                        return vsprintf($translation, $args);
+                    } else {
+                        return $translation;
+                    }
+                }
+            }
+        }
+        return '<span class="untranslated">'.$lookup.'</span>';
+    }
+
+    /**
+     * Lookup the translation text for a given lang and key
+     *
+     * @param $lang lang code
+     * @param $key  key to lookup with
+     *
+     * @return string
+     */
+    public function getTranslation($lang, $key) {
+        return $this->config->get('languages.'.$lang.'.'.$key, null);
+    }
 }

system/src/Grav/Common/Page/Pages.php

@@ -603,10 +603,9 @@ class Pages
 
         $content_exists = false;
         $pages_found = glob($directory.'/*'.CONTENT_EXT);
-        $page_extensions = $language->getValidPageExtensions();
+        $page_extensions = $language->getFallbackPageExtensions();
 
         if ($pages_found) {
-
             foreach ($page_extensions as $extension) {
                 foreach ($pages_found as $found) {
                     if (preg_match('/^.*\/[0-9A-Za-z\-\_]+('.$extension.')$/', $found)) {

system/src/Grav/Common/TwigExtension.php

@@ -16,11 +16,13 @@ class TwigExtension extends \Twig_Extension
 {
     protected $grav;
     protected $debugger;
+    protected $config;
 
     public function __construct()
     {
         $this->grav = Grav::instance();
         $this->debugger = isset($this->grav['debugger']) ? $this->grav['debugger'] : null;
+        $this->config = $this->grav['config'];
     }
 
     /**
@@ -54,7 +56,8 @@ class TwigExtension extends \Twig_Extension
             new \Twig_SimpleFilter('absolute_url', [$this, 'absoluteUrlFilter']),
             new \Twig_SimpleFilter('markdown', [$this, 'markdownFilter']),
             new \Twig_SimpleFilter('starts_with', [$this, 'startsWithFilter']),
-            new \Twig_SimpleFilter('ends_with', [$this, 'endsWithFilter'])
+            new \Twig_SimpleFilter('ends_with', [$this, 'endsWithFilter']),
+            new \Twig_SimpleFilter('t', [$this, 'translateFilter'])
         ];
     }
 
@@ -72,6 +75,7 @@ class TwigExtension extends \Twig_Extension
             new \Twig_SimpleFunction('debug', [$this, 'dump'], ['needs_context' => true, 'needs_environment' => true]),
             new \Twig_SimpleFunction('gist', [$this, 'gistFunc']),
             new \Twig_simpleFunction('random_string', [$this, 'randomStringFunc']),
+            new \Twig_simpleFunction('t', [$this, 'translateFunc'])
         ];
     }
 
@@ -335,7 +339,7 @@ class TwigExtension extends \Twig_Extension
     public function markdownFilter($string)
     {
         $page = $this->grav['page'];
-        $defaults = $this->grav['config']->get('system.pages.markdown');
+        $defaults = $this->$config->get('system.pages.markdown');
 
         // Initialize the preferred variant of Parsedown
         if ($defaults['extra']) {
@@ -359,6 +363,11 @@ class TwigExtension extends \Twig_Extension
         return Utils::endsWith($haystack, $needle);
     }
 
+    public function translateFilter()
+    {
+         return $this->grav['language']->translate(func_get_args());
+    }
+
     /**
      * Repeat given string x times.
      *
@@ -459,4 +468,9 @@ class TwigExtension extends \Twig_Extension
     {
         return Utils::generateRandomString($count);
     }
+
+    public function translateFunc()
+    {
+        return $this->grav['language']->translate(func_get_args());
+    }
 }