Add auto language detection

application/config/autoload.php

@@ -52,7 +52,7 @@ $autoload['packages'] = array(APPPATH.'third_party');
 |	$autoload['libraries'] = array('database', 'session', 'xmlrpc');
 */
 
-$autoload['libraries'] = array('database','session');
+$autoload['libraries'] = array('lang_detect', 'database', 'session');
 
 
 /*

application/config/lang_detect.php

@@ -0,0 +1,31 @@
+<?php defined('BASEPATH') || exit("No direct script access allowed");
+
+/**
+ * Mapping browser's primary language ID to supported language directory.
+ */
+$config['lang_available'] = array(
+    'en' => 'english',
+    'en-uk' => 'english',
+    'de' => 'german',
+    'de-at' => 'german'
+);
+
+/**
+ * Default language code. This language MUST be supported!
+ */
+$config['lang_default'] = 'en';
+
+/**
+ * Selected language code (is set by the language detection).
+ */
+$config['lang_selected'] = 'en';
+
+/**
+ * The name you want for the cookie.
+ */
+$config['lang_cookie_name'] = 'lang_select_language';
+
+/**
+ * The number of seconds you want the language to be remembered.
+ */
+$config['lang_expiration']  = 63072000;

application/libraries/Access.php

@@ -321,5 +321,5 @@ class Access {
 
 }
 
-/* End of file access.php */
+/* End of file Access.php */
-/* Location: ./application/libraries/access.php */
+/* Location: ./application/libraries/Access.php */

application/libraries/Lang_detect.php

@@ -0,0 +1,165 @@
+<?php defined('BASEPATH') || exit("No direct script access allowed");
+
+class Lang_detect {
+
+    protected $CI;
+
+    // make config item available locally
+    public $languages = array();
+
+    // the user's language (directory name)
+    public $lang_dir = '';
+
+    /**
+     * Constructor.
+     */
+    public function __construct() {
+        $this->CI =& get_instance();
+        $this->CI->load->config('lang_detect');
+        $this->CI->load->helper('cookie');
+
+        // get list of supported languages
+        $this->languages = $this->CI->config->item('lang_available');
+        if (empty($this->lang_dir)) {
+            // language directory not yet set: detect the user's language
+            $this->lang_dir = $this->detectLanguage();
+        }
+
+        log_message('debug', "Lang_detect Class Initialized");
+    }
+
+    /**
+     * Determine a user's language.
+     *
+     * Use either the URI segment's or the cookie's language code or determine
+     * the best match of the browser's languages with the available languages.
+     * If no match s found, the configured default language is taken.
+     *
+     * @return string Language directory name, e.g. 'english'
+     */
+    public function detectLanguage() {
+        $language = false;
+
+        // obtain language code from URI segment if available
+        $langURI = $this->uriLanguageDetect();
+        if ($langURI !== false) {
+            // check the URI's language code
+            $language = $this->checkLanguage($langURI);
+            if ($language !== false) {
+                $lang = $langURI;
+            }
+        }
+
+        // if a language cookie available get its sanitized info
+        $langCookie = get_cookie($this->CI->config->item('lang_cookie_name'));
+        if ($langCookie !== false) {
+            if (($language !== false) && ($langURI !== $langCookie)) {
+                // URI has valid language but cookie has wrong language: update cookie
+                $this->setLanguageCookie($langURI);
+            }
+            if ($language === false) {
+                // invalid or no URI language code: check the cookie's language
+                $language = $this->checkLanguage($langCookie);
+                if ($language !== false) {
+                    $lang = $langCookie;
+                }
+            }
+        }
+
+        if ($language === false) {
+            // no cookie/URI language code: check browser's languages
+            $accept_langs = $this->CI->input->server('HTTP_ACCEPT_LANGUAGE');
+            if ($accept_langs !== false) {
+                // explode languages into array
+                $accept_langs = strtolower($accept_langs);
+                $accept_langs = explode(",", $accept_langs);
+
+                // check all of them
+                foreach ($accept_langs as $lang) {
+                    // remove all after ';'
+                    $pos = strpos($lang, ';');
+                    if ($pos !== false) {
+                        $lang = substr($lang, 0, $pos);
+                    }
+                    // get CI language directory
+                    $language = $this->checkLanguage($lang);
+                    // finish search if we support that language
+                    if ($language !== false) {
+                        // set cookie
+                        $this->setLanguageCookie($lang);
+                        break;
+                    }
+                }
+            }
+        }
+
+        if ($language === false) {
+            // no base language available or no browser language match: use default
+            $lang = $this->CI->config->item('lang_default');
+            $language = $this->languages[$lang];
+            // set cookie
+            $this->setLanguageCookie($lang);
+        }
+
+        // set the configuration for the CI_Language class
+        $this->CI->config->set_item('language', $language);
+        // store the language code too
+        $this->CI->config->set_item('lang_selected', $lang);
+        return $language;
+    }
+
+    /**
+     * Sets the language cookie.
+     *
+     * @param string $lang The language code, e.g. en
+     */
+    private function setLanguageCookie($lang) {
+        set_cookie($this->CI->config->item('lang_cookie_name'), $lang,
+                $this->CI->config->item('lang_expiration'));
+    }
+
+    /**
+     * Fetches the language code from URI segment if available.
+     *
+     * @return mixed The language code, or FALSE if not found.
+     */
+    private function uriLanguageDetect() {
+        // search the language code in the uri segments
+        for ($i = $this->CI->uri->total_segments(); $i > 0; $i--) {
+            $segment = $this->CI->uri->segment($i);
+            // the uri segment with the language code has the prefix 'l_'
+            if (!empty($segment) && (strpos($segment, 'l_') === 0)) {
+                // extract the language code
+                return substr($segment, 2);
+            }
+        }
+        return false;
+    }
+
+    /**
+     * Determines the language directory.
+     *
+     * @param string $lang The language code, e.g. en_uk
+     * @return string The language directory, or FALSE if not found.
+     */
+    private function checkLanguage(&$lang) {
+        if (!array_key_exists($lang, $this->languages)) {
+            if (strlen($lang) == 2) {
+                // we had already the base language: not found so give up
+                return false;
+            } else {
+                // try base language
+                $lang = substr($lang, 0, 2);
+                if (!array_key_exists($lang, $this->languages)) {
+                    // calculated base language also not found: give up
+                    return false;
+                }
+            }
+        }
+        // return CI language directory
+        return $this->languages[$lang];
+    }
+}
+
+/* End of file Lang_detect.php */
+/* Location: ./application/libraries/Lang_detect.php */