Merge branch 'dev' into beta

20 files changed, 1429 insertions, 453 deletions

diff --git a/lib/Favicon/DataAccess.php b/lib/Favicon/DataAccess.php
new file mode 100644
index 000000000..2bfdf640e
--- /dev/null
+++ b/lib/Favicon/DataAccess.php
@@ -0,0 +1,40 @@
+<?php
+
+namespace Favicon;
+
+/**
+ * DataAccess is a wrapper used to read/write data locally or remotly
+ * Aside from SOLID principles, this wrapper is also useful to mock remote resources in unit tests
+ * Note: remote access warning are silenced because we don't care if a website is unreachable
+ **/
+class DataAccess {
+	public function retrieveUrl($url) {
+	    $this->set_context();
+	    return @file_get_contents($url);
+	}
+	
+	public function retrieveHeader($url) {
+	    $this->set_context();
+		return @get_headers($url, TRUE);
+	}
+	
+    public function saveCache($file, $data) {
+        file_put_contents($file, $data);
+    }
+    
+    public function readCache($file) {
+    	return file_get_contents($file);
+    }
+    
+    private function set_context() {
+        stream_context_set_default(
+            array(
+                'http' => array(
+                    'method' => 'GET',
+                    'timeout' => 10,
+                    'header' => "User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:20.0; Favicon; +https://github.com/ArthurHoaro/favicon) Gecko/20100101 Firefox/32.0\r\n",
+                )
+            )
+        );
+    }
+}
\ No newline at end of file
diff --git a/lib/Favicon/Favicon.php b/lib/Favicon/Favicon.php
new file mode 100644
index 000000000..7ea6ccf16
--- /dev/null
+++ b/lib/Favicon/Favicon.php
@@ -0,0 +1,293 @@
+<?php
+
+namespace Favicon;
+
+class Favicon
+{
+    protected $url = '';
+    protected $cacheDir;
+    protected $cacheTimeout;
+    protected $dataAccess;
+
+    public function __construct($args = array())
+    {
+        if (isset($args['url'])) {
+            $this->url = $args['url'];
+        }
+        
+        $this->cacheDir = __DIR__ . '/../../resources/cache';
+        $this->dataAccess = new DataAccess();
+    }
+
+    public function cache($args = array()) {
+        if (isset($args['dir'])) {
+            $this->cacheDir = $args['dir'];
+        }
+
+        if (!empty($args['timeout'])) {
+                $this->cacheTimeout = $args['timeout'];
+        } else {
+                $this->cacheTimeout = 0;
+        }
+    }
+
+    public static function baseUrl($url, $path = false)
+    {
+        $return = '';
+
+        if (!$url = parse_url($url)) {
+            return FALSE;
+        }
+
+        // Scheme
+        $scheme = isset($url['scheme']) ? strtolower($url['scheme']) : null;
+        if ($scheme != 'http' && $scheme != 'https') {
+
+            return FALSE;
+        }
+        $return .= "{$scheme}://";
+
+        // Username and password
+        if (isset($url['user'])) {
+            $return .= $url['user'];
+            if (isset($url['pass'])) {
+                $return .= ":{$url['pass']}";
+            }
+            $return .= '@';
+        }
+
+        // Hostname
+        if( !isset($url['host']) ) {
+            return FALSE;
+        }
+        
+        $return .= $url['host'];
+
+        // Port
+        if (isset($url['port'])) {
+            $return .= ":{$url['port']}";
+        }
+
+        // Path
+        if( $path && isset($url['path']) ) {
+            $return .= $url['path'];
+        }
+        $return .= '/';
+
+        return $return;    
+    }
+
+    public function info($url)
+    {
+        if(empty($url) || $url === false) {
+            return false;
+        }
+        
+        $max_loop = 5;
+        
+        // Discover real status by following redirects. 
+        $loop = TRUE;
+        while ($loop && $max_loop-- > 0) {
+            $headers = $this->dataAccess->retrieveHeader($url);
+            $exploded = explode(' ', $headers[0]);
+            
+            if( !isset($exploded[1]) ) { 
+                return false;
+            }
+            list(,$status) = $exploded;
+            
+            switch ($status) {
+                case '301':
+                case '302':
+                    $url = $headers['Location'];
+                    break;
+                default:
+                    $loop = FALSE;
+                    break;
+            }
+        }
+
+        return array('status' => $status, 'url' => $url);
+    }
+    
+    public function endRedirect($url) {
+        $out = $this->info($url);
+        return !empty($out['url']) ? $out['url'] : false;
+    }
+
+    /**
+     * Find remote (or cached) favicon
+     * @return favicon URL, false if nothing was found
+     **/
+    public function get($url = '')
+    {
+        // URLs passed to this method take precedence.
+        if (!empty($url)) {
+            $this->url = $url;
+        }
+
+        // Get the base URL without the path for clearer concatenations.
+        $original = rtrim($this->baseUrl($this->url, true), '/');
+        $url = rtrim($this->endRedirect($this->baseUrl($this->url, false)), '/');
+
+        if(($favicon = $this->checkCache($url)) || ($favicon = $this->getFavicon($url))) {
+            $base = true;
+        }
+        elseif(($favicon = $this->checkCache($original)) || ($favicon = $this->getFavicon($original, false))) {
+            $base = false;    
+        }
+        else
+            return false;
+            
+        // Save cache if necessary
+        $cache = $this->cacheDir . '/' . md5($base ? $url : $original);
+        if ($this->cacheTimeout && !file_exists($cache) || (is_writable($cache) && time() - filemtime($cache) > $this->cacheTimeout)) {
+            $this->dataAccess->saveCache($cache, $favicon);
+        }
+        
+        return $favicon;
+    }
+    
+    private function getFavicon($url, $checkDefault = true) {
+        $favicon = false;
+        
+        if(empty($url)) {
+            return false;
+        }
+        
+        // Try /favicon.ico first.
+        if( $checkDefault ) {
+            $info = $this->info("{$url}/favicon.ico");
+            if ($info['status'] == '200') {
+                $favicon = $info['url'];
+            }
+        }
+
+        // See if it's specified in a link tag in domain url.
+        if (!$favicon) {
+            $favicon = $this->getInPage($url);
+        }
+        
+        // Make sure the favicon is an absolute URL.
+        if( $favicon && filter_var($favicon, FILTER_VALIDATE_URL) === false ) {
+            $favicon = $url . '/' . $favicon;
+        }
+
+        // Sometimes people lie, so check the status.
+        // And sometimes, it's not even an image. Sneaky bastards!
+        // If cacheDir isn't writable, that's not our problem
+        if ($favicon && is_writable($this->cacheDir) && !$this->checkImageMType($favicon)) {
+            $favicon = false;
+        }
+
+        return $favicon;
+    }
+    
+    private function getInPage($url) {
+        $html = $this->dataAccess->retrieveUrl("{$url}/");
+        preg_match('!<head.*?>.*</head>!ims', $html, $match);
+        
+        if(empty($match) || count($match) == 0) {
+            return false;
+        }
+        
+        $head = $match[0];
+        
+        $dom = new \DOMDocument();
+        // Use error supression, because the HTML might be too malformed.
+        if (@$dom->loadHTML($head)) {
+            $links = $dom->getElementsByTagName('link');
+            foreach ($links as $link) {
+                if ($link->hasAttribute('rel') && strtolower($link->getAttribute('rel')) == 'shortcut icon') {
+                    return $link->getAttribute('href');
+                } elseif ($link->hasAttribute('rel') && strtolower($link->getAttribute('rel')) == 'icon') {
+                    return $link->getAttribute('href');
+                } elseif ($link->hasAttribute('href') && strpos($link->getAttribute('href'), 'favicon') !== FALSE) {
+                    return $link->getAttribute('href');
+                }
+            }
+        }
+        return false;
+    }
+    
+    private function checkCache($url) {
+        if ($this->cacheTimeout) {
+            $cache = $this->cacheDir . '/' . md5($url);
+            if (file_exists($cache) && is_readable($cache) && (time() - filemtime($cache) < $this->cacheTimeout)) {
+                return $this->dataAccess->readCache($cache);
+            }
+        } 
+        return false;
+    }
+    
+    private function checkImageMType($url) {
+        $tmpFile = $this->cacheDir . '/tmp.ico';
+        
+        $fileContent = $this->dataAccess->retrieveUrl($url);
+        $this->dataAccess->saveCache($tmpFile, $fileContent);
+        
+        $finfo = finfo_open(FILEINFO_MIME_TYPE);
+        $isImage = strpos(finfo_file($finfo, $tmpFile), 'image') !== false;
+        finfo_close($finfo);
+        
+        unlink($tmpFile);
+        
+        return $isImage;
+    }
+    
+    /**
+     * @return mixed
+     */
+    public function getCacheDir()
+    {
+        return $this->cacheDir;
+    }
+
+    /**
+     * @param mixed $cacheDir
+     */
+    public function setCacheDir($cacheDir)
+    {
+        $this->cacheDir = $cacheDir;
+    }
+
+    /**
+     * @return mixed
+     */
+    public function getCacheTimeout()
+    {
+        return $this->cacheTimeout;
+    }
+
+    /**
+     * @param mixed $cacheTimeout
+     */
+    public function setCacheTimeout($cacheTimeout)
+    {
+        $this->cacheTimeout = $cacheTimeout;
+    }
+
+    /**
+     * @return string
+     */
+    public function getUrl()
+    {
+        return $this->url;
+    }
+
+    /**
+     * @param string $url
+     */
+    public function setUrl($url)
+    {
+        $this->url = $url;
+    }
+
+    /**
+     * @param DataAccess $dataAccess
+     */
+    public function setDataAccess($dataAccess)
+    {
+        $this->dataAccess = $dataAccess;
+    }
+}
diff --git a/lib/Minz/BadConfigurationException.php b/lib/Minz/BadConfigurationException.php
deleted file mode 100644
index a7b77d687..000000000
--- a/lib/Minz/BadConfigurationException.php
+++ /dev/null
@@ -1,9 +0,0 @@
-<?php
-class Minz_BadConfigurationException extends Minz_Exception {
-	public function __construct ($part_missing, $code = self::ERROR) {
-		$message = '`' . $part_missing
-		         . '` in the configuration file is missing or is misconfigured';
-		
-		parent::__construct ($message, $code);
-	}
-}
diff --git a/lib/Minz/Configuration.php b/lib/Minz/Configuration.php
index 6cbc9fc0b..fe415e22b 100644
--- a/lib/Minz/Configuration.php
+++ b/lib/Minz/Configuration.php
@@ -1,419 +1,228 @@
 <?php
-/**
- * MINZ - Copyright 2011 Marien Fressinaud
- * Sous licence AGPL3 <http://www.gnu.org/licenses/>
-*/
 
 /**
- * La classe Configuration permet de gérer la configuration de l'application
+ * Manage configuration for the application.
  */
 class Minz_Configuration {
-	const CONF_PATH_NAME = '/config.php';
+	/**
+	 * The list of configurations.
+	 */
+	private static $config_list = array();
 
 	/**
-	 * VERSION est la version actuelle de MINZ
+	 * Add a new configuration to the list of configuration.
+	 *
+	 * @param $namespace the name of the current configuration
+	 * @param $config_filename the filename of the configuration
+	 * @param $default_filename a filename containing default values for the configuration
+	 * @param $configuration_setter an optional helper to set values in configuration
+	 * @throws Minz_ConfigurationNamespaceException if the namespace already exists.
 	 */
-	const VERSION = '1.3.1.freshrss';  // version spéciale FreshRSS
+	public static function register($namespace, $config_filename, $default_filename = null,
+	                                $configuration_setter = null) {
+		if (isset(self::$config_list[$namespace])) {
+			throw new Minz_ConfigurationNamespaceException(
+				$namespace . ' namespace already exists'
+			);
+		}
+
+		self::$config_list[$namespace] = new Minz_Configuration(
+			$namespace, $config_filename, $default_filename, $configuration_setter
+		);
+	}
 
 	/**
-	 * valeurs possibles pour l'"environment"
-	 * SILENT rend l'application muette (pas de log)
-	 * PRODUCTION est recommandée pour une appli en production
-	 *			(log les erreurs critiques)
-	 * DEVELOPMENT log toutes les erreurs
+	 * Parse a file and return its data.
+	 *
+	 * If the file does not contain a valid PHP code returning an array, an
+	 * empty array is returned anyway.
+	 *
+	 * @param $filename the name of the file to parse.
+	 * @return an array of values
+	 * @throws Minz_FileNotExistException if the file does not exist.
 	 */
-	const SILENT = 0;
-	const PRODUCTION = 1;
-	const DEVELOPMENT = 2;
+	public static function load($filename) {
+		if (!file_exists($filename)) {
+			throw new Minz_FileNotExistException($filename);
+		}
+
+		$data = @include($filename);
+		if (is_array($data)) {
+			return $data;
+		} else {
+			return array();
+		}
+	}
 
 	/**
-	 * définition des variables de configuration
-	 * $salt une chaîne de caractères aléatoires (obligatoire)
-	 * $environment gère le niveau d'affichage pour log et erreurs
-	 * $base_url le chemin de base pour accéder à l'application
-	 * $title le nom de l'application
-	 * $language la langue par défaut de l'application
-	 * $db paramètres pour la base de données (tableau)
-	 *     - host le serveur de la base
-	 *     - user nom d'utilisateur
-	 *     - password mot de passe de l'utilisateur
-	 *     - base le nom de la base de données
+	 * Return the configuration related to a given namespace.
+	 *
+	 * @param $namespace the name of the configuration to get.
+	 * @return a Minz_Configuration object
+	 * @throws Minz_ConfigurationNamespaceException if the namespace does not exist.
 	 */
-	private static $salt = '';
-	private static $environment = Minz_Configuration::PRODUCTION;
-	private static $base_url = '';
-	private static $title = '';
-	private static $language = 'en';
-	private static $default_user = '';
-	private static $allow_anonymous = false;
-	private static $allow_anonymous_refresh = false;
-	private static $auth_type = 'none';
-	private static $api_enabled = false;
-	private static $unsafe_autologin_enabled = false;
+	public static function get($namespace) {
+		if (!isset(self::$config_list[$namespace])) {
+			throw new Minz_ConfigurationNamespaceException(
+				$namespace . ' namespace does not exist'
+			);
+		}
 
-	private static $db = array (
-		'type' => 'mysql',
-		'host' => '',
-		'user' => '',
-		'password' => '',
-		'base' => '',
-		'prefix' => '',
-	);
+		return self::$config_list[$namespace];
+	}
 
-	const MAX_SMALL_INT = 16384;
-	private static $limits = array(
-		'cache_duration' => 800,	//SimplePie cache duration in seconds
-		'timeout' => 10,	//SimplePie timeout in seconds
-		'max_inactivity' => PHP_INT_MAX,	//Time in seconds after which a user who has not used the account is considered inactive (no auto-refresh of feeds).
-		'max_feeds' => Minz_Configuration::MAX_SMALL_INT,
-		'max_categories' => Minz_Configuration::MAX_SMALL_INT,
-	);
+	/**
+	 * The namespace of the current configuration.
+	 */
+	private $namespace = '';
 
-	/*
-	 * Getteurs
+	/**
+	 * The filename for the current configuration.
 	 */
-	public static function salt () {
-		return self::$salt;
-	}
-	public static function environment ($str = false) {
-		$env = self::$environment;
+	private $config_filename = '';
 
-		if ($str) {
-			switch (self::$environment) {
-			case self::SILENT:
-				$env = 'silent';
-				break;
-			case self::DEVELOPMENT:
-				$env = 'development';
-				break;
-			case self::PRODUCTION:
-			default:
-				$env = 'production';
-			}
-		}
+	/**
+	 * The filename for the current default values, null by default.
+	 */
+	private $default_filename = null;
 
-		return $env;
-	}
-	public static function baseUrl () {
-		return self::$base_url;
-	}
-	public static function title () {
-		return self::$title;
-	}
-	public static function language () {
-		return self::$language;
-	}
-	public static function dataBase () {
-		return self::$db;
-	}
-	public static function limits() {
-		return self::$limits;
-	}
-	public static function defaultUser () {
-		return self::$default_user;
-	}
-	public static function allowAnonymous() {
-		return self::$allow_anonymous;
-	}
-	public static function allowAnonymousRefresh() {
-		return self::$allow_anonymous_refresh;
-	}
-	public static function authType() {
-		return self::$auth_type;
-	}
-	public static function needsLogin() {
-		return self::$auth_type !== 'none';
-	}
-	public static function canLogIn() {
-		return self::$auth_type === 'form' || self::$auth_type === 'persona';
-	}
-	public static function apiEnabled() {
-		return self::$api_enabled;
-	}
-	public static function unsafeAutologinEnabled() {
-		return self::$unsafe_autologin_enabled;
-	}
+	/**
+	 * The configuration values, an empty array by default.
+	 */
+	private $data = array();
 
-	public static function _allowAnonymous($allow = false) {
-		self::$allow_anonymous = ((bool)$allow) && self::canLogIn();
-	}
-	public static function _allowAnonymousRefresh($allow = false) {
-		self::$allow_anonymous_refresh = ((bool)$allow) && self::allowAnonymous();
-	}
-	public static function _authType($value) {
-		$value = strtolower($value);
-		switch ($value) {
-			case 'form':
-			case 'http_auth':
-			case 'persona':
-			case 'none':
-				self::$auth_type = $value;
-				break;
-		}
-		self::_allowAnonymous(self::$allow_anonymous);
-	}
+	/**
+	 * The default values, an empty array by default.
+	 */
+	private $data_default = array();
 
-	public static function _enableApi($value = false) {
-		self::$api_enabled = (bool)$value;
+	/**
+	 * An object which help to set good values in configuration.
+	 */
+	private $configuration_setter = null;
+
+	public function removeExtension($ext_name) {
+		self::$extensions_enabled = array_diff(
+			self::$extensions_enabled,
+			array($ext_name)
+		);
 	}
-	public static function _enableAutologin($value = false) {
-		self::$unsafe_autologin_enabled = (bool)$value;
+	public function addExtension($ext_name) {
+		$found = array_search($ext_name, self::$extensions_enabled) !== false;
+		if (!$found) {
+			self::$extensions_enabled[] = $ext_name;
+		}
 	}
 
 	/**
-	 * Initialise les variables de configuration
-	 * @exception Minz_FileNotExistException si le CONF_PATH_NAME n'existe pas
-	 * @exception Minz_BadConfigurationException si CONF_PATH_NAME mal formaté
+	 * Create a new Minz_Configuration object.
+	 * 
+	 * @param $namespace the name of the current configuration.
+	 * @param $config_filename the file containing configuration values.
+	 * @param $default_filename the file containing default values, null by default.
+	 * @param $configuration_setter an optional helper to set values in configuration
 	 */
-	public static function init () {
+	private function __construct($namespace, $config_filename, $default_filename = null,
+	                             $configuration_setter = null) {
+		$this->namespace = $namespace;
+		$this->config_filename = $config_filename;
+
 		try {
-			self::parseFile ();
-			self::setReporting ();
+			$this->data = self::load($this->config_filename);
 		} catch (Minz_FileNotExistException $e) {
-			throw $e;
-		} catch (Minz_BadConfigurationException $e) {
-			throw $e;
+			if (is_null($default_filename)) {
+				throw $e;
+			}
 		}
-	}
 
-	public static function writeFile() {
-		$ini_array = array(
-			'general' => array(
-				'environment' => self::environment(true),
-				'salt' => self::$salt,
-				'base_url' => self::$base_url,
-				'title' => self::$title,
-				'default_user' => self::$default_user,
-				'allow_anonymous' => self::$allow_anonymous,
-				'allow_anonymous_refresh' => self::$allow_anonymous_refresh,
-				'auth_type' => self::$auth_type,
-				'api_enabled' => self::$api_enabled,
-				'unsafe_autologin_enabled' => self::$unsafe_autologin_enabled,
-			),
-			'limits' => self::$limits,
-			'db' => self::$db,
-		);
-		@rename(DATA_PATH . self::CONF_PATH_NAME, DATA_PATH . self::CONF_PATH_NAME . '.bak.php');
-		$result = file_put_contents(DATA_PATH . self::CONF_PATH_NAME, "<?php\n return " . var_export($ini_array, true) . ';');
-		if (function_exists('opcache_invalidate')) {
-			opcache_invalidate(DATA_PATH . self::CONF_PATH_NAME);	//Clear PHP 5.5+ cache for include
+		$this->default_filename = $default_filename;
+		if (!is_null($this->default_filename)) {
+			$this->data_default = self::load($this->default_filename);
 		}
-		return (bool)$result;
+
+		$this->_configurationSetter($configuration_setter);
 	}
 
 	/**
-	 * Parse un fichier de configuration
-	 * @exception Minz_PermissionDeniedException si le CONF_PATH_NAME n'est pas accessible
-	 * @exception Minz_BadConfigurationException si CONF_PATH_NAME mal formaté
+	 * Set a configuration setter for the current configuration.
+	 * @param $configuration_setter the setter to call when modifying data. It
+	 *        must implement an handle($key, $value) method.
 	 */
-	private static function parseFile () {
-		$ini_array = include(DATA_PATH . self::CONF_PATH_NAME);
-
-		if (!is_array($ini_array)) {
-			throw new Minz_PermissionDeniedException (
-				DATA_PATH . self::CONF_PATH_NAME,
-				Minz_Exception::ERROR
-			);
+	public function _configurationSetter($configuration_setter) {
+		if (is_callable(array($configuration_setter, 'handle'))) {
+			$this->configuration_setter = $configuration_setter;
 		}
+	}
 
-		// [general] est obligatoire
-		if (!isset ($ini_array['general'])) {
-			throw new Minz_BadConfigurationException (
-				'[general]',
-				Minz_Exception::ERROR
-			);
-		}
-		$general = $ini_array['general'];
-
-		// salt est obligatoire
-		if (!isset ($general['salt'])) {
-			if (isset($general['sel_application'])) {	//v0.6
-				$general['salt'] = $general['sel_application'];
-			} else {
-				throw new Minz_BadConfigurationException (
-					'salt',
-					Minz_Exception::ERROR
-				);
-			}
+	/**
+	 * Return the value of the given param.
+	 * 
+	 * @param $key the name of the param.
+	 * @param $default default value to return if key does not exist.
+	 * @return the value corresponding to the key.
+	 * @throws Minz_ConfigurationParamException if the param does not exist
+	 */
+	public function param($key, $default = null) {
+		if (isset($this->data[$key])) {
+			return $this->data[$key];
+		} elseif (!is_null($default)) {
+			return $default;
+		} elseif (isset($this->data_default[$key])) {
+			return $this->data_default[$key];
+		} else {
+			Minz_Log::warning($key . ' does not exist in configuration');
+			return null;
 		}
-		self::$salt = $general['salt'];
+	}
 
-		if (isset ($general['environment'])) {
-			switch ($general['environment']) {
-			case 'silent':
-				self::$environment = Minz_Configuration::SILENT;
-				break;
-			case 'development':
-				self::$environment = Minz_Configuration::DEVELOPMENT;
-				break;
-			case 'production':
-				self::$environment = Minz_Configuration::PRODUCTION;
-				break;
-			default:
-				if ($general['environment'] >= 0 &&
-					$general['environment'] <= 2) {
-					// fallback 0.7-beta
-					self::$environment = $general['environment'];
-				} else {
-					throw new Minz_BadConfigurationException (
-						'environment',
-						Minz_Exception::ERROR
-					);
-				}
-			}
+	/**
+	 * A wrapper for param().
+	 */
+	public function __get($key) {
+		return $this->param($key);
+	}
 
+	/**
+	 * Set or remove a param.
+	 *
+	 * @param $key the param name to set.
+	 * @param $value the value to set. If null, the key is removed from the configuration.
+	 */
+	public function _param($key, $value = null) {
+		if (!is_null($this->configuration_setter) && $this->configuration_setter->support($key)) {
+			$this->configuration_setter->handle($this->data, $key, $value);
+		} elseif (isset($this->data[$key]) && is_null($value)) {
+			unset($this->data[$key]);
+		} elseif (!is_null($value)) {
+			$this->data[$key] = $value;
 		}
-		if (isset ($general['base_url'])) {
-			self::$base_url = $general['base_url'];
-		}
+	}
 
-		if (isset ($general['title'])) {
-			self::$title = $general['title'];
-		}
-		if (isset ($general['language'])) {
-			self::$language = $general['language'];
-		}
-		if (isset ($general['default_user'])) {
-			self::$default_user = $general['default_user'];
-		}
-		if (isset ($general['auth_type'])) {
-			self::_authType($general['auth_type']);
-		}
-		if (isset ($general['allow_anonymous'])) {
-			self::$allow_anonymous = (
-				((bool)($general['allow_anonymous'])) &&
-				($general['allow_anonymous'] !== 'no')
-			);
-		}
-		if (isset ($general['allow_anonymous_refresh'])) {
-			self::$allow_anonymous_refresh = (
-				((bool)($general['allow_anonymous_refresh'])) &&
-				($general['allow_anonymous_refresh'] !== 'no')
-			);
-		}
-		if (isset ($general['api_enabled'])) {
-			self::$api_enabled = (
-				((bool)($general['api_enabled'])) &&
-				($general['api_enabled'] !== 'no')
-			);
-		}
-		if (isset ($general['unsafe_autologin_enabled'])) {
-			self::$unsafe_autologin_enabled = (
-				((bool)($general['unsafe_autologin_enabled'])) &&
-				($general['unsafe_autologin_enabled'] !== 'no')
-			);
-		}
+	/**
+	 * A wrapper for _param().
+	 */
+	public function __set($key, $value) {
+		$this->_param($key, $value);
+	}
 
-		if (isset($ini_array['limits'])) {
-			$limits = $ini_array['limits'];
-			if (isset($limits['cache_duration'])) {
-				$v = intval($limits['cache_duration']);
-				if ($v > 0) {
-					self::$limits['cache_duration'] = $v;
-				}
-			}
-			if (isset($limits['timeout'])) {
-				$v = intval($limits['timeout']);
-				if ($v > 0) {
-					self::$limits['timeout'] = $v;
-				}
-			}
-			if (isset($limits['max_inactivity'])) {
-				$v = intval($limits['max_inactivity']);
-				if ($v > 0) {
-					self::$limits['max_inactivity'] = $v;
-				}
-			}
-			if (isset($limits['max_feeds'])) {
-				$v = intval($limits['max_feeds']);
-				if ($v > 0 && $v < Minz_Configuration::MAX_SMALL_INT) {
-					self::$limits['max_feeds'] = $v;
-				}
-			}
-			if (isset($limits['max_categories'])) {
-				$v = intval($limits['max_categories']);
-				if ($v > 0 && $v < Minz_Configuration::MAX_SMALL_INT) {
-					self::$limits['max_categories'] = $v;
-				}
-			}
-		}
+	/**
+	 * Save the current configuration in the configuration file.
+	 */
+	public function save() {
+		$back_filename = $this->config_filename . '.bak.php';
+		@rename($this->config_filename, $back_filename);
 
-		// Base de données
-		if (isset ($ini_array['db'])) {
-			$db = $ini_array['db'];
-			if (empty($db['type'])) {
-				throw new Minz_BadConfigurationException (
-					'type',
-					Minz_Exception::ERROR
-				);
-			}
-			switch ($db['type']) {
-				case 'mysql':
-					if (empty($db['host'])) {
-						throw new Minz_BadConfigurationException (
-							'host',
-							Minz_Exception::ERROR
-						);
-					}
-					if (empty($db['user'])) {
-						throw new Minz_BadConfigurationException (
-							'user',
-							Minz_Exception::ERROR
-						);
-					}
-					if (!isset($db['password'])) {
-						throw new Minz_BadConfigurationException (
-							'password',
-							Minz_Exception::ERROR
-						);
-					}
-					if (empty($db['base'])) {
-						throw new Minz_BadConfigurationException (
-							'base',
-							Minz_Exception::ERROR
-						);
-					}
-					self::$db['host'] = $db['host'];
-					self::$db['user'] = $db['user'];
-					self::$db['password'] = $db['password'];
-					self::$db['base'] = $db['base'];
-					if (isset($db['prefix'])) {
-						self::$db['prefix'] = $db['prefix'];
-					}
-					break;
-				case 'sqlite':
-					self::$db['host'] = '';
-					self::$db['user'] = '';
-					self::$db['password'] = '';
-					self::$db['base'] = '';
-					self::$db['prefix'] = '';
-					break;
-				default:
-					throw new Minz_BadConfigurationException (
-						'type',
-						Minz_Exception::ERROR
-					);
-					break;
-			}
-			self::$db['type'] = $db['type'];
+		if (file_put_contents($this->config_filename,
+		                      "<?php\nreturn " . var_export($this->data, true) . ';',
+		                      LOCK_EX) === false) {
+			return false;
 		}
-	}
 
-	private static function setReporting() {
-		switch (self::$environment) {
-			case self::PRODUCTION:
-				error_reporting(E_ALL);
-				ini_set('display_errors','Off');
-				ini_set('log_errors', 'On');
-				break;
-			case self::DEVELOPMENT:
-				error_reporting(E_ALL);
-				ini_set('display_errors','On');
-				ini_set('log_errors', 'On');
-				break;
-			case self::SILENT:
-				error_reporting(0);
-				break;
+		// Clear PHP 5.5+ cache for include
+		if (function_exists('opcache_invalidate')) {
+			opcache_invalidate($this->config_filename);
 		}
+
+		return true;
 	}
 }
diff --git a/lib/Minz/ConfigurationException.php b/lib/Minz/ConfigurationException.php
new file mode 100644
index 000000000..f294c3341
--- /dev/null
+++ b/lib/Minz/ConfigurationException.php
@@ -0,0 +1,8 @@
+<?php
+
+class Minz_ConfigurationException extends Minz_Exception {
+	public function __construct($error, $code = self::ERROR) {
+		$message = 'Configuration error: ' . $error;
+		parent::__construct($message, $code);
+	}
+}
diff --git a/lib/Minz/ConfigurationNamespaceException.php b/lib/Minz/ConfigurationNamespaceException.php
new file mode 100644
index 000000000..f4278c5d6
--- /dev/null
+++ b/lib/Minz/ConfigurationNamespaceException.php
@@ -0,0 +1,4 @@
+<?php
+
+class Minz_ConfigurationNamespaceException extends Minz_ConfigurationException {
+}
diff --git a/lib/Minz/ConfigurationParamException.php b/lib/Minz/ConfigurationParamException.php
new file mode 100644
index 000000000..eac977935
--- /dev/null
+++ b/lib/Minz/ConfigurationParamException.php
@@ -0,0 +1,4 @@
+<?php
+
+class Minz_ConfigurationParamException extends Minz_ConfigurationException {
+}
diff --git a/lib/Minz/Dispatcher.php b/lib/Minz/Dispatcher.php
index f62a92911..125ce5757 100644
--- a/lib/Minz/Dispatcher.php
+++ b/lib/Minz/Dispatcher.php
@@ -15,6 +15,7 @@ class Minz_Dispatcher {
 	/* singleton */
 	private static $instance = null;
 	private static $needsReset;
+	private static $registrations = array();
 
 	private $controller;
 
@@ -38,7 +39,7 @@ class Minz_Dispatcher {
 			self::$needsReset = false;
 
 			try {
-				$this->createController ('FreshRSS_' . Minz_Request::controllerName () . '_Controller');
+				$this->createController (Minz_Request::controllerName ());
 				$this->controller->init ();
 				$this->controller->firstAction ();
 				if (!self::$needsReset) {
@@ -67,14 +68,18 @@ class Minz_Dispatcher {
 
 	/**
 	 * Instancie le Controller
-	 * @param $controller_name le nom du controller à instancier
+	 * @param $base_name le nom du controller à instancier
 	 * @exception ControllerNotExistException le controller n'existe pas
 	 * @exception ControllerNotActionControllerException controller n'est
 	 *          > pas une instance de ActionController
 	 */
-	private function createController ($controller_name) {
-		$filename = APP_PATH . self::CONTROLLERS_PATH_NAME . '/'
-		          . $controller_name . '.php';
+	private function createController ($base_name) {
+		if (self::isRegistered($base_name)) {
+			self::loadController($base_name);
+			$controller_name = 'FreshExtension_' . $base_name . '_Controller';
+		} else {
+			$controller_name = 'FreshRSS_' . $base_name . '_Controller';
+		}
 
 		if (!class_exists ($controller_name)) {
 			throw new Minz_ControllerNotExistException (
@@ -114,4 +119,42 @@ class Minz_Dispatcher {
 			$action_name
 		));
 	}
+
+	/**
+	 * Register a controller file.
+	 *
+	 * @param $base_name the base name of the controller (i.e. ./?c=<base_name>)
+	 * @param $base_path the base path where we should look into to find info.
+	 */
+	public static function registerController($base_name, $base_path) {
+		if (!self::isRegistered($base_name)) {
+			self::$registrations[$base_name] = $base_path;
+		}
+	}
+
+	/**
+	 * Return if a controller is registered.
+	 *
+	 * @param $base_name the base name of the controller.
+	 * @return true if the controller has been registered, false else.
+	 */
+	public static function isRegistered($base_name) {
+		return isset(self::$registrations[$base_name]);
+	}
+
+	/**
+	 * Load a controller file (include).
+	 *
+	 * @param $base_name the base name of the controller.
+	 */
+	private static function loadController($base_name) {
+		$base_path = self::$registrations[$base_name];
+		$controller_filename = $base_path . '/controllers/' . $base_name . 'Controller.php';
+		include_once $controller_filename;
+	}
+
+	private static function setViewPath($controller, $base_name) {
+		$base_path = self::$registrations[$base_name];
+		$controller->view()->setBasePathname($base_path);
+	}
 }
diff --git a/lib/Minz/Error.php b/lib/Minz/Error.php
index e5f3dff07..3eadc6d98 100644
--- a/lib/Minz/Error.php
+++ b/lib/Minz/Error.php
@@ -82,7 +82,8 @@ class Minz_Error {
 	 *       > en fonction de l'environment
 	 */
 	private static function processLogs ($logs) {
-		$env = Minz_Configuration::environment ();
+		$conf = Minz_Configuration::get('system');
+		$env = $conf->environment;
 		$logs_ok = array ();
 		$error = array ();
 		$warning = array ();
@@ -98,10 +99,10 @@ class Minz_Error {
 			$notice = $logs['notice'];
 		}
 
-		if ($env == Minz_Configuration::PRODUCTION) {
+		if ($env == 'production') {
 			$logs_ok = $error;
 		}
-		if ($env == Minz_Configuration::DEVELOPMENT) {
+		if ($env == 'development') {
 			$logs_ok = array_merge ($error, $warning, $notice);
 		}
 
diff --git a/lib/Minz/Extension.php b/lib/Minz/Extension.php
new file mode 100644
index 000000000..d7ee8fe81
--- /dev/null
+++ b/lib/Minz/Extension.php
@@ -0,0 +1,208 @@
+<?php
+
+/**
+ * The extension base class.
+ */
+class Minz_Extension {
+	private $name;
+	private $entrypoint;
+	private $path;
+	private $author;
+	private $description;
+	private $version;
+	private $type;
+
+	public static $authorized_types = array(
+		'system',
+		'user',
+	);
+
+	private $is_enabled;
+
+	/**
+	 * The constructor to assign specific information to the extension.
+	 *
+	 * Available fields are:
+	 * - name: the name of the extension (required).
+	 * - entrypoint: the extension class name (required).
+	 * - path: the pathname to the extension files (required).
+	 * - author: the name and / or email address of the extension author.
+	 * - description: a short description to describe the extension role.
+	 * - version: a version for the current extension.
+	 * - type: "system" or "user" (default).
+	 *
+	 * It must not be redefined by child classes.
+	 *
+	 * @param $meta_info contains information about the extension.
+	 */
+	public function __construct($meta_info) {
+		$this->name = $meta_info['name'];
+		$this->entrypoint = $meta_info['entrypoint'];
+		$this->path = $meta_info['path'];
+		$this->author = isset($meta_info['author']) ? $meta_info['author'] : '';
+		$this->description = isset($meta_info['description']) ? $meta_info['description'] : '';
+		$this->version = isset($meta_info['version']) ? $meta_info['version'] : '0.1';
+		$this->setType(isset($meta_info['type']) ? $meta_info['type'] : 'user');
+
+		$this->is_enabled = false;
+	}
+
+	/**
+	 * Used when installing an extension (e.g. update the database scheme).
+	 *
+	 * It must be redefined by child classes.
+	 *
+	 * @return true if the extension has been installed or a string explaining
+	 *         the problem.
+	 */
+	public function install() {
+		return true;
+	}
+
+	/**
+	 * Used when uninstalling an extension (e.g. revert the database scheme to
+	 * cancel changes from install).
+	 *
+	 * It must be redefined by child classes.
+	 *
+	 * @return true if the extension has been uninstalled or a string explaining
+	 *         the problem.
+	 */
+	public function uninstall() {
+		return true;
+	}
+
+	/**
+	 * Call at the initialization of the extension (i.e. when the extension is
+	 * enabled by the extension manager).
+	 *
+	 * It must be redefined by child classes.
+	 */
+	public function init() {}
+
+	/**
+	 * Set the current extension to enable.
+	 */
+	public function enable() {
+		$this->is_enabled = true;
+	}
+
+	/**
+	 * Return if the extension is currently enabled.
+	 *
+	 * @return true if extension is enabled, false else.
+	 */
+	public function isEnabled() {
+		return $this->is_enabled;
+	}
+
+	/**
+	 * Return the content of the configure view for the current extension.
+	 *
+	 * @return the html content from ext_dir/configure.phtml, false if it does
+	 *         not exist.
+	 */
+	public function getConfigureView() {
+		$filename = $this->path . '/configure.phtml';
+		if (!file_exists($filename)) {
+			return false;
+		}
+
+		ob_start();
+		include($filename);
+		return ob_get_clean();
+	}
+
+	/**
+	 * Handle the configure action.
+	 *
+	 * It must be redefined by child classes.
+	 */
+	public function handleConfigureAction() {}
+
+	/**
+	 * Getters and setters.
+	 */
+	public function getName() {
+		return $this->name;
+	}
+	public function getEntrypoint() {
+		return $this->entrypoint;
+	}
+	public function getPath() {
+		return $this->path;
+	}
+	public function getAuthor() {
+		return $this->author;
+	}
+	public function getDescription() {
+		return $this->description;
+	}
+	public function getVersion() {
+		return $this->version;
+	}
+	public function getType() {
+		return $this->type;
+	}
+	private function setType($type) {
+		if (!in_array($type, self::$authorized_types)) {
+			throw new Minz_ExtensionException('invalid `type` info', $this->name);
+		}
+		$this->type = $type;
+	}
+
+	/**
+	 * Return the url for a given file.
+	 *
+	 * @param $filename name of the file to serve.
+	 * @param $type the type (js or css) of the file to serve.
+	 * @return the url corresponding to the file.
+	 */
+	public function getFileUrl($filename, $type) {
+		$dir = substr(strrchr($this->path, '/'), 1);
+		$file_name_url = urlencode($dir . '/static/' . $filename);
+
+		$absolute_path = $this->path . '/static/' . $filename;
+		$mtime = @filemtime($absolute_path);
+
+		$url = '/ext.php?f=' . $file_name_url .
+		       '&amp;t=' . $type .
+		       '&amp;' . $mtime;
+		return Minz_Url::display($url);
+	}
+
+	/**
+	 * Register a controller in the Dispatcher.
+	 *
+	 * @param @base_name the base name of the controller. Final name will be:
+	 *                   FreshExtension_<base_name>_Controller.
+	 */
+	public function registerController($base_name) {
+		Minz_Dispatcher::registerController($base_name, $this->path);
+	}
+
+	/**
+	 * Register the views in order to be accessible by the application.
+	 */
+	public function registerViews() {
+		Minz_View::addBasePathname($this->path);
+	}
+
+	/**
+	 * Register i18n files from ext_dir/i18n/
+	 */
+	public function registerTranslates() {
+		$i18n_dir = $this->path . '/i18n';
+		Minz_Translate::registerPath($i18n_dir);
+	}
+
+	/**
+	 * Register a new hook.
+	 *
+	 * @param $hook_name the hook name (must exist).
+	 * @param $hook_function the function name to call (must be callable).
+	 */
+	public function registerHook($hook_name, $hook_function) {
+		Minz_ExtensionManager::addHook($hook_name, $hook_function, $this);
+	}
+}
diff --git a/lib/Minz/ExtensionException.php b/lib/Minz/ExtensionException.php
new file mode 100644
index 000000000..647f1a9b9
--- /dev/null
+++ b/lib/Minz/ExtensionException.php
@@ -0,0 +1,15 @@
+<?php
+
+class Minz_ExtensionException extends Minz_Exception {
+	public function __construct ($message, $extension_name = false, $code = self::ERROR) {
+		if ($extension_name) {
+			$message = 'An error occured in `' . $extension_name
+			         . '` extension with the message: ' . $message;
+		} else {
+			$message = 'An error occured in an unnamed '
+			         . 'extension with the message: ' . $message;
+		}
+
+		parent::__construct($message, $code);
+	}
+}
diff --git a/lib/Minz/ExtensionManager.php b/lib/Minz/ExtensionManager.php
new file mode 100644
index 000000000..7edc7afaa
--- /dev/null
+++ b/lib/Minz/ExtensionManager.php
@@ -0,0 +1,298 @@
+<?php
+
+/**
+ * An extension manager to load extensions present in EXTENSIONS_PATH.
+ *
+ * @todo see coding style for methods!!
+ */
+class Minz_ExtensionManager {
+	private static $ext_metaname = 'metadata.json';
+	private static $ext_entry_point = 'extension.php';
+	private static $ext_list = array();
+	private static $ext_list_enabled = array();
+
+	private static $ext_auto_enabled = array();
+
+	// List of available hooks. Please keep this list sorted.
+	private static $hook_list = array(
+		'entry_before_display' => array(  // function($entry) -> Entry | null
+			'list' => array(),
+			'signature' => 'OneToOne',
+		),
+		'entry_before_insert' => array(  // function($entry) -> Entry | null
+			'list' => array(),
+			'signature' => 'OneToOne',
+		),
+		'feed_before_insert' => array(  // function($feed) -> Feed | null
+			'list' => array(),
+			'signature' => 'OneToOne',
+		),
+		'post_update' => array(  // function(none) -> none
+			'list' => array(),
+			'signature' => 'NoneToNone',
+		),
+	);
+	private static $ext_to_hooks = array();
+
+	/**
+	 * Initialize the extension manager by loading extensions in EXTENSIONS_PATH.
+	 *
+	 * A valid extension is a directory containing metadata.json and
+	 * extension.php files.
+	 * metadata.json is a JSON structure where the only required fields are
+	 * `name` and `entry_point`.
+	 * extension.php should contain at least a class named <name>Extension where
+	 * <name> must match with the entry point in metadata.json. This class must
+	 * inherit from Minz_Extension class.
+	 */
+	public static function init() {
+		$list_potential_extensions = array_values(array_diff(
+			scandir(EXTENSIONS_PATH),
+			array('..', '.')
+		));
+
+		$system_conf = Minz_Configuration::get('system');
+		self::$ext_auto_enabled = $system_conf->extensions_enabled;
+
+		foreach ($list_potential_extensions as $ext_dir) {
+			$ext_pathname = EXTENSIONS_PATH . '/' . $ext_dir;
+			$metadata_filename = $ext_pathname . '/' . self::$ext_metaname;
+
+			// Try to load metadata file.
+			if (!file_exists($metadata_filename)) {
+				// No metadata file? Invalid!
+				continue;
+			}
+			$meta_raw_content = file_get_contents($metadata_filename);
+			$meta_json = json_decode($meta_raw_content, true);
+			if (!$meta_json || !self::isValidMetadata($meta_json)) {
+				// metadata.json is not a json file? Invalid!
+				// or metadata.json is invalid (no required information), invalid!
+				Minz_Log::warning('`' . $metadata_filename . '` is not a valid metadata file');
+				continue;
+			}
+
+			$meta_json['path'] = $ext_pathname;
+
+			// Try to load extension itself
+			$extension = self::load($meta_json);
+			if (!is_null($extension)) {
+				self::register($extension);
+			}
+		}
+	}
+
+	/**
+	 * Indicates if the given parameter is a valid metadata array.
+	 *
+	 * Required fields are:
+	 * - `name`: the name of the extension
+	 * - `entry_point`: a class name to load the extension source code
+	 * If the extension class name is `TestExtension`, entry point will be `Test`.
+	 * `entry_point` must be composed of alphanumeric characters.
+	 *
+	 * @param $meta is an array of values.
+	 * @return true if the array is valid, false else.
+	 */
+	public static function isValidMetadata($meta) {
+		$valid_chars = array('_');
+		return !(empty($meta['name']) ||
+		         empty($meta['entrypoint']) ||
+		         !ctype_alnum(str_replace($valid_chars, '', $meta['entrypoint'])));
+	}
+
+	/**
+	 * Load the extension source code based on info metadata.
+	 *
+	 * @param $info an array containing information about extension.
+	 * @return an extension inheriting from Minz_Extension.
+	 */
+	public static function load($info) {
+		$entry_point_filename = $info['path'] . '/' . self::$ext_entry_point;
+		$ext_class_name = $info['entrypoint'] . 'Extension';
+
+		include($entry_point_filename);
+
+		// Test if the given extension class exists.
+		if (!class_exists($ext_class_name)) {
+			Minz_Log::warning('`' . $ext_class_name .
+			                  '` cannot be found in `' . $entry_point_filename . '`');
+			return null;
+		}
+
+		// Try to load the class.
+		$extension = null;
+		try {
+			$extension = new $ext_class_name($info);
+		} catch (Minz_ExtensionException $e) {
+			// We cannot load the extension? Invalid!
+			Minz_Log::warning('In `' . $metadata_filename . '`: ' . $e->getMessage());
+			return null;
+		}
+
+		// Test if class is correct.
+		if (!($extension instanceof Minz_Extension)) {
+			Minz_Log::warning('`' . $ext_class_name .
+			                  '` is not an instance of `Minz_Extension`');
+			return null;
+		}
+
+		return $extension;
+	}
+
+	/**
+	 * Add the extension to the list of the known extensions ($ext_list).
+	 *
+	 * If the extension is present in $ext_auto_enabled and if its type is "system",
+	 * it will be enabled in the same time.
+	 *
+	 * @param $ext a valid extension.
+	 */
+	public static function register($ext) {
+		$name = $ext->getName();
+		self::$ext_list[$name] = $ext;
+
+		if ($ext->getType() === 'system' &&
+				in_array($name, self::$ext_auto_enabled)) {
+			self::enable($ext->getName());
+		}
+
+		self::$ext_to_hooks[$name] = array();
+	}
+
+	/**
+	 * Enable an extension so it will be called when necessary.
+	 *
+	 * The extension init() method will be called.
+	 *
+	 * @param $ext_name is the name of a valid extension present in $ext_list.
+	 */
+	public static function enable($ext_name) {
+		if (isset(self::$ext_list[$ext_name])) {
+			$ext = self::$ext_list[$ext_name];
+			self::$ext_list_enabled[$ext_name] = $ext;
+			$ext->enable();
+			$ext->init();
+		}
+	}
+
+	/**
+	 * Enable a list of extensions.
+	 *
+	 * @param $ext_list the names of extensions we want to load.
+	 */
+	public static function enableByList($ext_list) {
+		foreach ($ext_list as $ext_name) {
+			self::enable($ext_name);
+		}
+	}
+
+	/**
+	 * Return a list of extensions.
+	 *
+	 * @param $only_enabled if true returns only the enabled extensions (false by default).
+	 * @return an array of extensions.
+	 */
+	public static function listExtensions($only_enabled = false) {
+		if ($only_enabled) {
+			return self::$ext_list_enabled;
+		} else {
+			return self::$ext_list;
+		}
+	}
+
+	/**
+	 * Return an extension by its name.
+	 *
+	 * @param $ext_name the name of the extension.
+	 * @return the corresponding extension or null if it doesn't exist.
+	 */
+	public static function findExtension($ext_name) {
+		if (!isset(self::$ext_list[$ext_name])) {
+			return null;
+		}
+
+		return self::$ext_list[$ext_name];
+	}
+
+	/**
+	 * Add a hook function to a given hook.
+	 *
+	 * The hook name must be a valid one. For the valid list, see self::$hook_list
+	 * array keys.
+	 *
+	 * @param $hook_name the hook name (must exist).
+	 * @param $hook_function the function name to call (must be callable).
+	 * @param $ext the extension which register the hook.
+	 */
+	public static function addHook($hook_name, $hook_function, $ext) {
+		if (isset(self::$hook_list[$hook_name]) && is_callable($hook_function)) {
+			self::$hook_list[$hook_name]['list'][] = $hook_function;
+			self::$ext_to_hooks[$ext->getName()][] = $hook_name;
+		}
+	}
+
+	/**
+	 * Call functions related to a given hook.
+	 *
+	 * The hook name must be a valid one. For the valid list, see self::$hook_list
+	 * array keys.
+	 *
+	 * @param $hook_name the hook to call.
+	 * @param additionnal parameters (for signature, please see self::$hook_list).
+	 * @return the final result of the called hook.
+	 */
+	public static function callHook($hook_name) {
+		if (!isset(self::$hook_list[$hook_name])) {
+			return;
+		}
+
+		$signature = self::$hook_list[$hook_name]['signature'];
+		$signature = 'self::call' . $signature;
+		$args = func_get_args();
+
+		return call_user_func_array($signature, $args);
+	}
+
+	/**
+	 * Call a hook which takes one argument and return a result.
+	 *
+	 * The result is chained between the extension, for instance, first extension
+	 * hook will receive the initial argument and return a result which will be
+	 * passed as an argument to the next extension hook and so on.
+	 *
+	 * If a hook return a null value, the method is stopped and return null.
+	 *
+	 * @param $hook_name is the hook to call.
+	 * @param $arg is the argument to pass to the first extension hook.
+	 * @return the final chained result of the hooks. If nothing is changed,
+	 *         the initial argument is returned.
+	 */
+	private static function callOneToOne($hook_name, $arg) {
+		$result = $arg;
+		foreach (self::$hook_list[$hook_name]['list'] as $function) {
+			$result = call_user_func($function, $arg);
+
+			if (is_null($result)) {
+				break;
+			}
+
+			$arg = $result;
+		}
+		return $result;
+	}
+
+	/**
+	 * Call a hook which takes no argument and returns nothing.
+	 *
+	 * This case is simpler than callOneToOne because hooks are called one by
+	 * one, without any consideration of argument nor result.
+	 *
+	 * @param $hook_name is the hook to call.
+	 */
+	private static function callNoneToNone($hook_name) {
+		foreach (self::$hook_list[$hook_name]['list'] as $function) {
+			call_user_func($function);
+		}
+	}
+}
diff --git a/lib/Minz/FrontController.php b/lib/Minz/FrontController.php
index e95c56bf3..f9eff3db6 100644
--- a/lib/Minz/FrontController.php
+++ b/lib/Minz/FrontController.php
@@ -30,14 +30,13 @@ class Minz_FrontController {
 	 * Initialise le dispatcher, met à jour la Request
 	 */
 	public function __construct () {
-		if (LOG_PATH === false) {
-			$this->killApp ('Path not found: LOG_PATH');
-		}
-
 		try {
-			Minz_Configuration::init ();
+			Minz_Configuration::register('system',
+			                             DATA_PATH . '/config.php',
+			                             DATA_PATH . '/config.default.php');
+			$this->setReporting();
 
-			Minz_Request::init ();
+			Minz_Request::init();
 
 			$url = $this->buildUrl();
 			$url['params'] = array_merge (
@@ -114,4 +113,23 @@ class Minz_FrontController {
 		}
 		exit ('### Application problem ###<br />'."\n".$txt);
 	}
+
+	private function setReporting() {
+		$conf = Minz_Configuration::get('system');
+		switch($conf->environment) {
+		case 'production':
+			error_reporting(E_ALL);
+			ini_set('display_errors','Off');
+			ini_set('log_errors', 'On');
+			break;
+		case 'development':
+			error_reporting(E_ALL);
+			ini_set('display_errors','On');
+			ini_set('log_errors', 'On');
+			break;
+		case 'silent':
+			error_reporting(0);
+			break;
+		}
+	}
 }
diff --git a/lib/Minz/Log.php b/lib/Minz/Log.php
index d3eaec2ae..2a9e10993 100644
--- a/lib/Minz/Log.php
+++ b/lib/Minz/Log.php
@@ -28,16 +28,21 @@ class Minz_Log {
 	 * 	- level = NOTICE et environment = PRODUCTION
 	 * @param $information message d'erreur / information à enregistrer
 	 * @param $level niveau d'erreur
-	 * @param $file_name fichier de log, par défaut LOG_PATH/application.log
+	 * @param $file_name fichier de log
 	 */
 	public static function record ($information, $level, $file_name = null) {
-		$env = Minz_Configuration::environment ();
+		try {
+			$conf = Minz_Configuration::get('system');
+			$env = $conf->environment;
+		} catch (Minz_ConfigurationException $e) {
+			$env = 'production';
+		}
 
-		if (! ($env === Minz_Configuration::SILENT
-		       || ($env === Minz_Configuration::PRODUCTION
+		if (! ($env === 'silent'
+		       || ($env === 'production'
 		       && ($level >= Minz_Log::NOTICE)))) {
 			if ($file_name === null) {
-				$file_name = LOG_PATH . '/' . Minz_Session::param('currentUser', '_') . '.log';
+				$file_name = join_path(USERS_PATH, Minz_Session::param('currentUser', '_'), 'log.txt');
 			}
 
 			switch ($level) {
@@ -71,7 +76,7 @@ class Minz_Log {
 	 * Automatise le log des variables globales $_GET et $_POST
 	 * Fait appel à la fonction record(...)
 	 * Ne fonctionne qu'en environnement "development"
-	 * @param $file_name fichier de log, par défaut LOG_PATH/application.log
+	 * @param $file_name fichier de log
 	 */
 	public static function recordRequest($file_name = null) {
 		$msg_get = str_replace("\n", '', '$_GET content : ' . print_r($_GET, true));
diff --git a/lib/Minz/ModelPdo.php b/lib/Minz/ModelPdo.php
index 6198cd85c..ac7a1bed7 100644
--- a/lib/Minz/ModelPdo.php
+++ b/lib/Minz/ModelPdo.php
@@ -44,7 +44,8 @@ class Minz_ModelPdo {
 			return;
 		}
 
-		$db = Minz_Configuration::dataBase();
+		$conf = Minz_Configuration::get('system');
+		$db = $conf->db;
 
 		if ($currentUser === null) {
 			$currentUser = Minz_Session::param('currentUser', '_');
@@ -63,7 +64,7 @@ class Minz_ModelPdo {
 				);
 				$this->prefix = $db['prefix'] . $currentUser . '_';
 			} elseif ($type === 'sqlite') {
-				$string = 'sqlite:' . DATA_PATH . '/' . $currentUser . '.sqlite';
+				$string = 'sqlite:' . join_path(DATA_PATH, 'users', $currentUser, 'db.sqlite');
 				$driver_options = array(
 					//PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
 				);
diff --git a/lib/Minz/Request.php b/lib/Minz/Request.php
index 4b97a3caf..6db2e9c7a 100644
--- a/lib/Minz/Request.php
+++ b/lib/Minz/Request.php
@@ -96,7 +96,8 @@ class Minz_Request {
 	 * @return la base de l'url
 	 */
 	public static function getBaseUrl() {
-		$defaultBaseUrl = Minz_Configuration::baseUrl();
+		$conf = Minz_Configuration::get('system');
+		$defaultBaseUrl = $conf->base_url;
 		if (!empty($defaultBaseUrl)) {
 			return $defaultBaseUrl;
 		} elseif (isset($_SERVER['REQUEST_URI'])) {
diff --git a/lib/Minz/Session.php b/lib/Minz/Session.php
index af4de75bb..cfe8debe9 100644
--- a/lib/Minz/Session.php
+++ b/lib/Minz/Session.php
@@ -55,7 +55,7 @@ class Minz_Session {
 
 		if (!$force) {
 			self::_param('language', $language);
-			Minz_Translate::reset();
+			Minz_Translate::reset($language);
 		}
 	}
 
diff --git a/lib/Minz/Translate.php b/lib/Minz/Translate.php
index e7efb8665..baddcb424 100644
--- a/lib/Minz/Translate.php
+++ b/lib/Minz/Translate.php
@@ -10,14 +10,19 @@
  */
 class Minz_Translate {
 	/**
+	 * $path_list is the list of registered base path to search translations.
+	 */
+	private static $path_list = array();
+
+	/**
 	 * $lang_name is the name of the current language to use.
 	 */
 	private static $lang_name;
 
 	/**
-	 * $lang_path is the pathname of i18n files (e.g. ./app/i18n/en/).
+	 * $lang_files is a list of registered i18n files.
 	 */
-	private static $lang_path;
+	private static $lang_files = array();
 
 	/**
 	 * $translates is a cache for i18n translation.
@@ -25,19 +30,121 @@ class Minz_Translate {
 	private static $translates = array();
 
 	/**
-	 * Load $lang_name and $lang_path based on configuration and selected language.
+	 * Init the translation object.
+	 * @param $lang_name the lang to show.
+	 */
+	public static function init($lang_name = null) {
+		self::$lang_name = $lang_name;
+		self::$lang_files = array();
+		self::$translates = array();
+		self::registerPath(APP_PATH . '/i18n');
+		foreach (self::$path_list as $path) {
+			self::loadLang($path);
+		}
+	}
+
+	/**
+	 * Reset the translation object with a new language.
+	 * @param $lang_name the new language to use
+	 */
+	public static function reset($lang_name) {
+		self::$lang_name = $lang_name;
+		self::$lang_files = array();
+		self::$translates = array();
+		foreach (self::$path_list as $path) {
+			self::loadLang($path);
+		}
+	}
+
+	/**
+	 * Return the list of available languages.
+	 * @return an array containing langs found in different registered paths.
+	 */
+	public static function availableLanguages() {
+		$list_langs = array();
+
+		foreach (self::$path_list as $path) {
+			$path_langs = array_values(array_diff(
+				scandir($path),
+				array('..', '.')
+			));
+
+			$list_langs = array_merge($list_langs, $path_langs);
+		}
+
+		return array_unique($list_langs);
+	}
+
+	/**
+	 * Register a new path.
+	 * @param $path a path containing i18n directories (e.g. ./en/, ./fr/).
+	 */
+	public static function registerPath($path) {
+		if (in_array($path, self::$path_list)) {
+			return;
+		}
+
+		self::$path_list[] = $path;
+		self::loadLang($path);
+	}
+
+	/**
+	 * Load translations of the current language from the given path.
+	 * @param $path the path containing i18n directories.
 	 */
-	public static function init() {
-		$l = Minz_Configuration::language();
-		self::$lang_name = Minz_Session::param('language', $l);
-		self::$lang_path = APP_PATH . '/i18n/' . self::$lang_name . '/';
+	private static function loadLang($path) {
+		$lang_path = $path . '/' . self::$lang_name;
+		if (!file_exists($lang_path) || is_null(self::$lang_name)) {
+			// The lang path does not exist, nothing more to do.
+			return;
+		}
+
+		$list_i18n_files = array_values(array_diff(
+			scandir($lang_path),
+			array('..', '.')
+		));
+
+		// Each file basename correspond to a top-level i18n key. For each of
+		// these keys we store the file pathname and mark translations must be
+		// reloaded (by setting $translates[$i18n_key] to null).
+		foreach ($list_i18n_files as $i18n_filename) {
+			$i18n_key = basename($i18n_filename, '.php');
+			if (!isset(self::$lang_files[$i18n_key])) {
+				self::$lang_files[$i18n_key] = array();
+			}
+			self::$lang_files[$i18n_key][] = $lang_path . '/' . $i18n_filename;
+			self::$translates[$i18n_key] = null;
+		}
 	}
 
 	/**
-	 * Alias for init().
+	 * Load the files associated to $key into $translates.
+	 * @param $key the top level i18n key we want to load.
 	 */
-	public static function reset() {
-		self::init();
+	private static function loadKey($key) {
+		// The top level key is not in $lang_files, it means it does not exist!
+		if (!isset(self::$lang_files[$key])) {
+			Minz_Log::debug($key . ' is not a valid top level key');
+			return false;
+		}
+
+		self::$translates[$key] = array();
+
+		foreach (self::$lang_files[$key] as $lang_pathname) {
+			$i18n_array = include($lang_pathname);
+			if (!is_array($i18n_array)) {
+				Minz_Log::warning('`' . $lang_pathname . '` does not contain a PHP array');
+				continue;
+			}
+
+			// We must avoid to erase previous data so we just override them if
+			// needed.
+			self::$translates[$key] = array_replace_recursive(
+				self::$translates[$key], $i18n_array
+			);
+		}
+
+		return true;
 	}
 
 	/**
@@ -57,16 +164,14 @@ class Minz_Translate {
 			$top_level = array_shift($group);
 		}
 
-		$filename = self::$lang_path . $top_level . '.php';
-
-		// Try to load the i18n file if it's not done yet.
-		if (!isset(self::$translates[$top_level])) {
-			if (!file_exists($filename)) {
-				Minz_Log::debug($top_level . ' is not a valid top level key');
+		// If $translates[$top_level] is null it means we have to load the
+		// corresponding files.
+		if (!isset(self::$translates[$top_level]) ||
+				is_null(self::$translates[$top_level])) {
+			$res = self::loadKey($top_level);
+			if (!$res) {
 				return $key;
 			}
-
-			self::$translates[$top_level] = include($filename);
 		}
 
 		// Go through the i18n keys to get the correct translation value.
diff --git a/lib/Minz/View.php b/lib/Minz/View.php
index b40448491..ff5cce4a5 100644
--- a/lib/Minz/View.php
+++ b/lib/Minz/View.php
@@ -13,8 +13,9 @@ class Minz_View {
 	const LAYOUT_FILENAME = '/layout.phtml';
 
 	private $view_filename = '';
-	private $use_layout = null;
+	private $use_layout = true;
 
+	private static $base_pathnames = array(APP_PATH);
 	private static $title = '';
 	private static $styles = array ();
 	private static $scripts = array ();
@@ -28,26 +29,35 @@ class Minz_View {
 	public function __construct () {
 		$this->change_view(Minz_Request::controllerName(),
 		                   Minz_Request::actionName());
-		self::$title = Minz_Configuration::title ();
+
+		$conf = Minz_Configuration::get('system');
+		self::$title = $conf->title;
 	}
 
 	/**
 	 * Change le fichier de vue en fonction d'un controller / action
 	 */
 	public function change_view($controller_name, $action_name) {
-		$this->view_filename = APP_PATH
-		                     . self::VIEWS_PATH_NAME . '/'
+		$this->view_filename = self::VIEWS_PATH_NAME . '/'
 		                     . $controller_name . '/'
 		                     . $action_name . '.phtml';
 	}
 
 	/**
+	 * Add a base pathname to search views.
+	 *
+	 * New pathnames will be added at the beginning of the list.
+	 *
+	 * @param $base_pathname the new base pathname.
+	 */
+	public static function addBasePathname($base_pathname) {
+		array_unshift(self::$base_pathnames, $base_pathname);
+	}
+
+	/**
 	 * Construit la vue
 	 */
 	public function build () {
-		if ($this->use_layout === null) {	//TODO: avoid file_exists and require views to be explicit
-			$this->use_layout = file_exists (APP_PATH . self::LAYOUT_PATH_NAME . self::LAYOUT_FILENAME);
-		}
 		if ($this->use_layout) {
 			$this->buildLayout ();
 		} else {
@@ -56,21 +66,39 @@ class Minz_View {
 	}
 
 	/**
+	 * Include a view file.
+	 *
+	 * The file is searched inside list of $base_pathnames.
+	 *
+	 * @param $filename the name of the file to include.
+	 * @return true if the file has been included, false else.
+	 */
+	private function includeFile($filename) {
+		// We search the filename in the list of base pathnames. Only the first view
+		// found is considered.
+		foreach (self::$base_pathnames as $base) {
+			$absolute_filename = $base . $filename;
+			if (file_exists($absolute_filename)) {
+				include $absolute_filename;
+				return true;
+			}
+		}
+
+		return false;
+	}
+
+	/**
 	 * Construit le layout
 	 */
 	public function buildLayout () {
-		include (
-			APP_PATH
-			. self::LAYOUT_PATH_NAME
-			. self::LAYOUT_FILENAME
-		);
+		$this->includeFile(self::LAYOUT_PATH_NAME . self::LAYOUT_FILENAME);
 	}
 
 	/**
 	 * Affiche la Vue en elle-même
 	 */
 	public function render () {
-		if ((include($this->view_filename)) === false) {
+		if (!$this->includeFile($this->view_filename)) {
 			Minz_Log::notice('File not found: `' . $this->view_filename . '`');
 		}
 	}
@@ -80,11 +108,8 @@ class Minz_View {
 	 * @param $part l'élément partial à ajouter
 	 */
 	public function partial ($part) {
-		$fic_partial = APP_PATH
-		             . self::LAYOUT_PATH_NAME . '/'
-		             . $part . '.phtml';
-
-		if ((include($fic_partial)) === false) {
+		$fic_partial = self::LAYOUT_PATH_NAME . '/' . $part . '.phtml';
+		if (!$this->includeFile($fic_partial)) {
 			Minz_Log::warning('File not found: `' . $fic_partial . '`');
 		}
 	}
@@ -94,11 +119,8 @@ class Minz_View {
 	 * @param $helper l'élément à afficher
 	 */
 	public function renderHelper ($helper) {
-		$fic_helper = APP_PATH
-		            . '/views/helpers/'
-		            . $helper . '.phtml';
-
-		if ((include($fic_helper)) === false) {;
+		$fic_helper = '/views/helpers/' . $helper . '.phtml';
+		if (!$this->includeFile($fic_helper)) {
 			Minz_Log::warning('File not found: `' . $fic_helper . '`');
 		}
 	}
diff --git a/lib/lib_rss.php b/lib/lib_rss.php
index 264c69d58..083e87745 100644
--- a/lib/lib_rss.php
+++ b/lib/lib_rss.php
@@ -15,6 +15,17 @@ if (!function_exists('json_encode')) {
 	}
 }
 
+/**
+ * Build a directory path by concatenating a list of directory names.
+ *
+ * @param $path_parts a list of directory names
+ * @return a string corresponding to the final pathname
+ */
+function join_path() {
+	$path_parts = func_get_args();
+	return join(DIRECTORY_SEPARATOR, $path_parts);
+}
+
 //<Auto-loading>
 function classAutoloader($class) {
 	if (strpos($class, 'FreshRSS') === 0) {
@@ -108,7 +119,8 @@ function html_only_entity_decode($text) {
 }
 
 function customSimplePie() {
-	$limits = Minz_Configuration::limits();
+	$system_conf = Minz_Configuration::get('system');
+	$limits = $system_conf->limits;
 	$simplePie = new SimplePie();
 	$simplePie->set_useragent(_t('gen.freshrss') . '/' . FRESHRSS_VERSION . ' (' . PHP_OS . '; ' . FRESHRSS_WEBSITE . ') ' . SIMPLEPIE_NAME . '/' . SIMPLEPIE_VERSION);
 	$simplePie->set_cache_location(CACHE_PATH);
@@ -205,21 +217,53 @@ function uSecString() {
 
 function invalidateHttpCache() {
 	Minz_Session::_param('touch', uTimeString());
-	return touch(LOG_PATH . '/' . Minz_Session::param('currentUser', '_') . '.log');
+	return touch(join_path(DATA_PATH, 'users', Minz_Session::param('currentUser', '_'), 'log.txt'));
 }
 
-function usernameFromPath($userPath) {
-	if (preg_match('%/([A-Za-z0-9]{1,16})_user\.php$%', $userPath, $matches)) {
-		return $matches[1];
-	} else {
-		return '';
+function listUsers() {
+	$final_list = array();
+	$base_path = join_path(DATA_PATH, 'users');
+	$dir_list = array_values(array_diff(
+		scandir($base_path),
+		array('..', '.', '_')
+	));
+
+	foreach ($dir_list as $file) {
+		if (is_dir(join_path($base_path, $file))) {
+			$final_list[] = $file;
+		}
 	}
+
+	return $final_list;
 }
 
-function listUsers() {
-	return array_map('usernameFromPath', glob(DATA_PATH . '/*_user.php'));
+
+/**
+ * Register and return the configuration for a given user.
+ *
+ * Note this function has been created to generate temporary configuration
+ * objects. If you need a long-time configuration, please don't use this function.
+ *
+ * @param $username the name of the user of which we want the configuration.
+ * @return a Minz_Configuration object, null if the configuration cannot be loaded.
+ */
+function get_user_configuration($username) {
+	$namespace = time() . '_user_' . $username;
+	try {
+		Minz_Configuration::register($namespace,
+		                             join_path(USERS_PATH, $username, 'config.php'),
+		                             join_path(USERS_PATH, '_', 'config.default.php'));
+	} catch (Minz_ConfigurationNamespaceException $e) {
+		// namespace already exists, do nothing.
+	} catch (Minz_FileNotExistException $e) {
+		Minz_Log::warning($e->getMessage());
+		return null;
+	}
+
+	return Minz_Configuration::get($namespace);
 }
 
+
 function httpAuthUser() {
 	return isset($_SERVER['REMOTE_USER']) ? $_SERVER['REMOTE_USER'] : '';
 }
@@ -284,7 +328,7 @@ function check_install_files() {
 	return array(
 		'data' => DATA_PATH && is_writable(DATA_PATH),
 		'cache' => CACHE_PATH && is_writable(CACHE_PATH),
-		'logs' => LOG_PATH && is_writable(LOG_PATH),
+		'users' => USERS_PATH && is_writable(USERS_PATH),
 		'favicons' => is_writable(DATA_PATH . '/favicons'),
 		'persona' => is_writable(DATA_PATH . '/persona'),
 		'tokens' => is_writable(DATA_PATH . '/tokens'),
@@ -319,3 +363,69 @@ function check_install_database() {
 
 	return $status;
 }
+
+/**
+ * Remove a directory recursively.
+ *
+ * From http://php.net/rmdir#110489
+ *
+ * @param $dir the directory to remove
+ */
+function recursive_unlink($dir) {
+	if (!is_dir($dir)) {
+		return true;
+	}
+
+	$files = array_diff(scandir($dir), array('.', '..'));
+	foreach ($files as $filename) {
+		$filename = $dir . '/' . $filename;
+		if (is_dir($filename)) {
+			@chmod($filename, 0777);
+			recursive_unlink($filename);
+		} else {
+			unlink($filename);
+		}
+	}
+
+	return rmdir($dir);
+}
+
+
+/**
+ * Remove queries where $get is appearing.
+ * @param $get the get attribute which should be removed.
+ * @param $queries an array of queries.
+ * @return the same array whithout those where $get is appearing.
+ */
+function remove_query_by_get($get, $queries) {
+	$final_queries = array();
+	foreach ($queries as $key => $query) {
+		if (empty($query['get']) || $query['get'] !== $get) {
+			$final_queries[$key] = $query;
+		}
+	}
+	return $final_queries;
+}
+
+
+/**
+ * Add a value in an array and take care it is unique.
+ * @param $array the array in which we add the value.
+ * @param $value the value to add.
+ */
+function array_push_unique(&$array, $value) {
+	$found = array_search($value, $array) !== false;
+	if (!$found) {
+		$array[] = $value;
+	}
+}
+
+
+/**
+ * Remove a value from an array.
+ * @param $array the array from wich value is removed.
+ * @param $value the value to remove.
+ */
+function array_remove(&$array, $value) {
+	$array = array_diff($array, array($value));
+}