adding configuration option to set a default language and/or force it,

resolves #39

lib/configuration.php

@@ -43,6 +43,7 @@ class configuration
             'notice' => '',
             'base64version' => '2.1.9',
             'languageselection' => false,
+            'languagedefault' => '',
         ),
         'expire' => array(
             'default' => '1week',

lib/i18n.php

@@ -26,6 +26,15 @@ class i18n
      */
     protected static $_language = 'en';
 
+    /**
+     * language fallback
+     *
+     * @access protected
+     * @static
+     * @var    string
+     */
+    protected static $_languageFallback = 'en';
+
     /**
      * language labels
      *
@@ -248,6 +257,20 @@ class i18n
         return array_intersect_key(self::$_languageLabels, array_flip($languages));
     }
 
+    /**
+     * set the default language
+     *
+     * @access public
+     * @static
+     * @param  string $lang
+     * @return void
+     */
+    public static function setLanguageFallback($lang)
+    {
+        if (in_array($lang, self::getAvailableLanguages()))
+            self::$_languageFallback = $lang;
+    }
+
     /**
      * get language file path
      *
@@ -339,7 +362,7 @@ class i18n
         }
         if (count($matches) === 0)
         {
-            return 'en';
+            return self::$_languageFallback;
         }
         krsort($matches);
         $topmatches = current($matches);

lib/zerobin.php

@@ -185,6 +185,16 @@ class zerobin
         $this->_model = new model($this->_conf);
         $this->_request = new request;
         $this->_urlbase = array_key_exists('REQUEST_URI', $_SERVER) ? $_SERVER['REQUEST_URI'] : '/';
+
+        // set default language
+        $lang = $this->_conf->getKey('languagedefault');
+        i18n::setLanguageFallback($lang);
+        // force default language, if language selection is disabled and a default is set
+        if (!$this->_conf->getKey('languageselection') && strlen($lang) == 2)
+        {
+            $_COOKIE['lang'] = $lang;
+            setcookie('lang', $lang);
+        }
     }
 
     /**
@@ -448,6 +458,13 @@ class zerobin
         $page->draw($this->_conf->getKey('template'));
     }
 
+    /**
+     * outputs requested JSON-LD context
+     *
+     * @access private
+     * @param string $type
+     * @return void
+     */
     private function _jsonld($type)
     {
         if (
@@ -475,7 +492,7 @@ class zerobin
     }
 
     /**
-     * return JSON encoded message and exit
+     * prepares JSON encoded status message
      *
      * @access private
      * @param  bool $status