class.symphony.php

<?php

/**
 * @package core
 */
/**
 * The Symphony class is an abstract class that implements the
 * Singleton interface. It provides the glue that forms the Symphony
 * CMS and initialises the toolkit classes. Symphony is extended by
 * the Frontend and Administration classes
 */
require_once CORE . '/class.errorhandler.php';
require_once CORE . '/class.configuration.php';
require_once CORE . '/class.log.php';
require_once CORE . '/class.cookie.php';
require_once FACE . '/interface.singleton.php';
require_once TOOLKIT . '/class.page.php';
require_once TOOLKIT . '/class.ajaxpage.php';
require_once TOOLKIT . '/class.xmlelement.php';
require_once TOOLKIT . '/class.widget.php';
require_once TOOLKIT . '/class.general.php';
require_once TOOLKIT . '/class.cryptography.php';
require_once TOOLKIT . '/class.xsrf.php';
require_once TOOLKIT . '/class.profiler.php';
require_once TOOLKIT . '/class.author.php';
require_once TOOLKIT . '/class.email.php';
require_once TOOLKIT . '/class.mysql.php';
require_once TOOLKIT . '/class.extensionmanager.php';
require_once TOOLKIT . '/class.pagemanager.php';
require_once TOOLKIT . '/class.authormanager.php';
require_once TOOLKIT . '/class.emailgatewaymanager.php';
require_once TOOLKIT . '/class.entrymanager.php';
require_once TOOLKIT . '/class.fieldmanager.php';
require_once TOOLKIT . '/class.sectionmanager.php';
require_once TOOLKIT . '/class.textformattermanager.php';
require_once TOOLKIT . '/class.datasourcemanager.php';
require_once TOOLKIT . '/class.eventmanager.php';

abstract class Symphony implements Singleton
{
    /**
     * An instance of the Symphony class, either `Administration` or `Frontend`.
     * @var Symphony
     */
    protected static $_instance = null;

    /**
     * An instance of the Profiler class
     * @var Profiler
     */
    protected static $Profiler = null;

    /**
     * An instance of the `Configuration` class
     * @var Configuration
     */
    private static $Configuration = null;

    /**
     * An instance of the `Database` class
     * @var MySQL
     */
    private static $Database = null;

    /**
     * An instance of the `ExtensionManager` class
     * @var ExtensionManager
     */
    private static $ExtensionManager = null;

    /**
     * An instance of the `Log` class
     * @var Log
     */
    private static $Log = null;

    /**
     * The current page namespace, used for translations
     * @since Symphony 2.3
     * @var string
     */
    private static $namespace = false;

    /**
     * An instance of the Cookie class
     * @var Cookie
     */
    public static $Cookie = null;

    /**
     * An instance of the currently logged in Author
     * @var Author
     */
    public static $Author = null;

    /**
     * A previous exception that has been fired. Defaults to null.
     * @since Symphony 2.3.2
     * @var Exception
     */
    private static $exception = null;

    /**
     * The Symphony constructor initialises the class variables of Symphony.
     * It will set the DateTime settings, define new date constants and initialise
     * the correct Language for the currently logged in Author. If magic quotes
     * are enabled, Symphony will sanitize the `$_SERVER`, `$_COOKIE`,
     * `$_GET` and `$_POST` arrays. The constructor loads in
     * the initial Configuration values from the `CONFIG` file
     */
    protected function __construct()
    {
        self::$Profiler = Profiler::instance();

        if (get_magic_quotes_gpc()) {
            General::cleanArray($_SERVER);
            General::cleanArray($_COOKIE);
            General::cleanArray($_GET);
            General::cleanArray($_POST);
        }

        // Set date format throughout the system
        define_safe('__SYM_DATE_FORMAT__', self::Configuration()->get('date_format', 'region'));
        define_safe('__SYM_TIME_FORMAT__', self::Configuration()->get('time_format', 'region'));
        define_safe('__SYM_DATETIME_FORMAT__', __SYM_DATE_FORMAT__ . self::Configuration()->get('datetime_separator', 'region') . __SYM_TIME_FORMAT__);
        DateTimeObj::setSettings(self::Configuration()->get('region'));

        // Initialise logging
        self::initialiseLog();
        GenericExceptionHandler::initialise(self::Log());
        GenericErrorHandler::initialise(self::Log());

        // Initialize language management
        Lang::initialize();
        Lang::set(self::$Configuration->get('lang', 'symphony'));

        self::initialiseCookie();

        // If the user is not a logged in Author, turn off the verbose error messages.
        if (!self::isLoggedIn() && is_null(self::$Author)) {
            GenericExceptionHandler::$enabled = false;
        }

        // Engine is ready.
        self::$Profiler->sample('Engine Initialisation');
    }

    /**
     * Accessor for the Symphony instance, whether it be Frontend
     * or Administration
     *
     * @since Symphony 2.2
     * @throws Exception
     * @return Symphony
     */
    public static function Engine()
    {
        if (class_exists('Administration')) {
            return Administration::instance();
        } elseif (class_exists('Frontend')) {
            return Frontend::instance();
        } else {
            throw new Exception(__('No suitable engine object found'));
        }
    }

    /**
     * Setter for `$Configuration`. This function initialise the configuration
     * object and populate its properties based on the given $array.
     *
     * @since Symphony 2.3
     * @param array $data
     *  An array of settings to be stored into the Configuration object
     */
    public static function initialiseConfiguration(array $data = array())
    {
        if (empty($data)) {
            // Includes the existing CONFIG file and initialises the Configuration
            // by setting the values with the setArray function.
            include CONFIG;

            $data = $settings;
        }

        self::$Configuration = new Configuration(true);
        self::$Configuration->setArray($data);
    }

    /**
     * Accessor for the current `Configuration` instance. This contains
     * representation of the the Symphony config file.
     *
     * @return Configuration
     */
    public static function Configuration()
    {
        return self::$Configuration;
    }

    /**
     * Is XSRF enabled for this Symphony install?
     *
     * @since Symphony 2.4
     * @return boolean
     */
    public static function isXSRFEnabled()
    {
        return self::Configuration()->get('enable_xsrf', 'symphony') === 'yes';
    }

    /**
     * Accessor for the current `Profiler` instance.
     *
     * @since Symphony 2.3
     * @return Profiler
     */
    public static function Profiler()
    {
        return self::$Profiler;
    }

    /**
     * Setter for `$Log`. This function uses the configuration
     * settings in the 'log' group in the Configuration to create an instance. Date
     * formatting options are also retrieved from the configuration.
     *
     * @param string $filename (optional)
     *  The file to write the log to, if omitted this will default to `ACTIVITY_LOG`
     * @throws Exception
     * @return bool|void
     */
    public static function initialiseLog($filename = null)
    {
        if (self::$Log instanceof Log && self::$Log->getLogPath() == $filename) {
            return true;
        }

        if (is_null($filename)) {
            $filename = ACTIVITY_LOG;
        }

        self::$Log = new Log($filename);
        self::$Log->setArchive((self::Configuration()->get('archive', 'log') == '1' ? true : false));
        self::$Log->setMaxSize(intval(self::Configuration()->get('maxsize', 'log')));
        self::$Log->setDateTimeFormat(self::Configuration()->get('date_format', 'region') . ' ' . self::Configuration()->get('time_format', 'region'));

        if (self::$Log->open(Log::APPEND, self::Configuration()->get('write_mode', 'file')) == '1') {
            self::$Log->initialise('Symphony Log');
        }
    }

    /**
     * Accessor for the current `Log` instance
     *
     * @since Symphony 2.3
     * @return Log
     */
    public static function Log()
    {
        return self::$Log;
    }

    /**
     * Setter for `$Cookie`. This will use PHP's parse_url
     * function on the current URL to set a cookie using the cookie_prefix
     * defined in the Symphony configuration. The cookie will last two
     * weeks.
     *
     * This function also defines two constants, `__SYM_COOKIE_PATH__`
     * and `__SYM_COOKIE_PREFIX__`.
     *
     * @deprecated Prior to Symphony 2.3.2, the constant `__SYM_COOKIE_PREFIX_`
     *  had a typo where it was missing the second underscore. Symphony will
     *  support both constants, `__SYM_COOKIE_PREFIX_` and `__SYM_COOKIE_PREFIX__`
     *  until Symphony 2.6.0.
     */
    public static function initialiseCookie()
    {
        $cookie_path = @parse_url(URL, PHP_URL_PATH);
        $cookie_path = '/' . trim($cookie_path, '/');

        define_safe('__SYM_COOKIE_PATH__', $cookie_path);
        define_safe('__SYM_COOKIE_PREFIX_', self::Configuration()->get('cookie_prefix', 'symphony'));
        define_safe('__SYM_COOKIE_PREFIX__', self::Configuration()->get('cookie_prefix', 'symphony'));

        self::$Cookie = new Cookie(__SYM_COOKIE_PREFIX__, TWO_WEEKS, __SYM_COOKIE_PATH__);
    }

    /**
     * Accessor for the current `$Cookie` instance.
     *
     * @since Symphony 2.5.0
     * @return Cookie
     */
    public static function Cookie() {
        return self::$Cookie;
    }

    /**
     * Setter for `$ExtensionManager` using the current
     * Symphony instance as the parent. If for some reason this fails,
     * a Symphony Error page will be thrown
     * @param Boolean $force (optional)
     *  When set to true, this function will always create a new
     *  instance of ExtensionManager, replacing self::$ExtensionManager.
     */
    public static function initialiseExtensionManager($force=false)
    {
        if (!$force && self::$ExtensionManager instanceof ExtensionManager) {
            return true;
        }

        self::$ExtensionManager = new ExtensionManager;

        if (!(self::$ExtensionManager instanceof ExtensionManager)) {
            self::throwCustomError(__('Error creating Symphony extension manager.'));
        }
    }

    /**
     * Accessor for the current `$ExtensionManager` instance.
     *
     * @since Symphony 2.2
     * @return ExtensionManager
     */
    public static function ExtensionManager()
    {
        return self::$ExtensionManager;
    }

    /**
     * Setter for `$Database`, accepts a Database object. If `$database`
     * is omitted, this function will set `$Database` to be of the `MySQL`
     * class.
     *
     * @since Symphony 2.3
     * @param StdClass $database (optional)
     *  The class to handle all Database operations, if omitted this function
     *  will set `self::$Database` to be an instance of the `MySQL` class.
     * @return boolean
     *  This function will always return true
     */
    public static function setDatabase(StdClass $database = null)
    {
        if (self::Database()) {
            return true;
        }

        self::$Database = !is_null($database) ? $database : new MySQL;

        return true;
    }

    /**
     * Accessor for the current `$Database` instance.
     *
     * @return MySQL
     */
    public static function Database()
    {
        return self::$Database;
    }

    /**
     * This will initialise the Database class and attempt to create a connection
     * using the connection details provided in the Symphony configuration. If any
     * errors occur whilst doing so, a Symphony Error Page is displayed.
     *
     * @throws SymphonyErrorPage
     * @return boolean
     *  This function will return true if the `$Database` was
     *  initialised successfully.
     */
    public static function initialiseDatabase()
    {
        self::setDatabase();

        $details = self::Configuration()->get('database');

        try {
            if (!self::Database()->connect($details['host'], $details['user'], $details['password'], $details['port'], $details['db'])) {
                return false;
            }

            if (!self::Database()->isConnected()) {
                return false;
            }

            self::Database()->setPrefix($details['tbl_prefix']);
            self::Database()->setCharacterEncoding();
            self::Database()->setCharacterSet();

            // Set Timezone, need to convert human readable, ie. Australia/Brisbane to be +10:00
            // @see https://github.com/symphonycms/symphony-2/issues/1726
            $timezone = self::Configuration()->get('timezone', 'region');
            $symphony_date = new DateTime('now', new DateTimeZone($timezone));

            // MySQL wants the offset to be in the format +/-H:I, getOffset returns offset in seconds
            $utc = new DateTime('now ' . $symphony_date->getOffset() . ' seconds', new DateTimeZone("UTC"));

            // On PHP5.3+ we can use DateInterval to format the difference
            // in way that MySQL will be happy
            $offset = $symphony_date->diff($utc)->format('%R%H:%I');

            self::Database()->setTimeZone($offset);

            if (self::Configuration()->get('query_caching', 'database') == 'off') {
                self::Database()->disableCaching();
            } elseif (self::Configuration()->get('query_caching', 'database') == 'on') {
                self::Database()->enableCaching();
            }
        } catch (DatabaseException $e) {
            self::throwCustomError(
                $e->getDatabaseErrorCode() . ': ' . $e->getDatabaseErrorMessage(),
                __('Symphony Database Error'),
                Page::HTTP_STATUS_ERROR,
                'database',
                array(
                    'error' => $e,
                    'message' => __('There was a problem whilst attempting to establish a database connection. Please check all connection information is correct.') . ' ' . __('The following error was returned:')
                )
            );
        }

        return true;
    }

    /**
     * Accessor for the current `$Author` instance.
     *
     * @since Symphony 2.5.0
     * @return Author
     */
    public static function Author() {
        return self::$Author;
    }

    /**
     * Attempts to log an Author in given a username and password.
     * If the password is not hashed, it will be hashed using the sha1
     * algorithm. The username and password will be sanitized before
     * being used to query the Database. If an Author is found, they
     * will be logged in and the sanitized username and password (also hashed)
     * will be saved as values in the `$Cookie`.
     *
     * @see toolkit.General#hash()
     * @param string $username
     *  The Author's username. This will be sanitized before use.
     * @param string $password
     *  The Author's password. This will be sanitized and then hashed before use
     * @param boolean $isHash
     *  If the password provided is already hashed, setting this parameter to
     *  true will stop it becoming rehashed. By default it is false.
     * @throws DatabaseException
     * @return boolean
     *  True if the Author was logged in, false otherwise
     */
    public static function login($username, $password, $isHash = false)
    {
        $username = self::Database()->cleanValue($username);
        $password = self::Database()->cleanValue($password);

        if (strlen(trim($username)) > 0 && strlen(trim($password)) > 0) {
            $author = AuthorManager::fetch('id', 'ASC', 1, null, sprintf(
                "`username` = '%s'",
                $username
            ));

            if (!empty($author) && Cryptography::compare($password, current($author)->get('password'), $isHash)) {
                self::$Author = current($author);

                // Only migrate hashes if there is no update available as the update might change the tbl_authors table.
                if (self::isUpgradeAvailable() === false && Cryptography::requiresMigration(self::$Author->get('password'))) {
                    self::$Author->set('password', Cryptography::hash($password));

                    self::Database()->update(array('password' => self::$Author->get('password')), 'tbl_authors', sprintf(
                        " `id` = %d", self::$Author->get('id')
                    ));
                }

                self::$Cookie->set('username', $username);
                self::$Cookie->set('pass', self::$Author->get('password'));

                self::Database()->update(array(
                    'last_seen' => DateTimeObj::get('Y-m-d H:i:s')),
                    'tbl_authors',
                    sprintf(" `id` = %d", self::$Author->get('id'))
                );

                return true;
            }
        }

        return false;
    }

    /**
     * Symphony allows Authors to login via the use of tokens instead of
     * a username and password. A token is derived from concatenating the
     * Author's username and password and applying the sha1 hash to
     * it, from this, a portion of the hash is used as the token. This is a useful
     * feature often used when setting up other Authors accounts or if an
     * Author forgets their password.
     *
     * @param string $token
     *  The Author token, which is a portion of the hashed string concatenation
     *  of the Author's username and password
     * @throws DatabaseException
     * @return boolean
     *  True if the Author is logged in, false otherwise
     */
    public static function loginFromToken($token)
    {
        $token = self::Database()->cleanValue($token);

        if (strlen(trim($token)) == 0) {
            return false;
        }

        if (strlen($token) == 6 || strlen($token) == 16) {
            $row = self::Database()->fetchRow(0, sprintf(
                "SELECT `a`.`id`, `a`.`username`, `a`.`password`
                FROM `tbl_authors` AS `a`, `tbl_forgotpass` AS `f`
                WHERE `a`.`id` = `f`.`author_id`
                AND `f`.`expiry` > '%s'
                AND `f`.`token` = '%s'
                LIMIT 1",
                DateTimeObj::getGMT('c'),
                $token
            ));

            self::Database()->delete('tbl_forgotpass', sprintf(" `token` = '%s' ", $token));
        } else {
            $row = self::Database()->fetchRow(0, sprintf(
                "SELECT `id`, `username`, `password`
                FROM `tbl_authors`
                WHERE SUBSTR(%s(CONCAT(`username`, `password`)), 1, 8) = '%s'
                AND `auth_token_active` = 'yes'
                LIMIT 1",
                'SHA1',
                $token
            ));
        }

        if ($row) {
            self::$Author = AuthorManager::fetchByID($row['id']);
            self::$Cookie->set('username', $row['username']);
            self::$Cookie->set('pass', $row['password']);
            self::Database()->update(array('last_seen' => DateTimeObj::getGMT('Y-m-d H:i:s')), 'tbl_authors', sprintf("
                `id` = %d", $row['id']
            ));

            return true;
        }

        return false;
    }

    /**
     * This function will destroy the currently logged in `$Author`
     * session, essentially logging them out.
     *
     * @see core.Cookie#expire()
     */
    public static function logout()
    {
        self::$Cookie->expire();
    }

    /**
     * This function determines whether an there is a currently logged in
     * Author for Symphony by using the `$Cookie`'s username
     * and password. If an Author is found, they will be logged in, otherwise
     * the `$Cookie` will be destroyed.
     *
     * @see core.Cookie#expire()
     */
    public static function isLoggedIn()
    {
        // Ensures that we're in the real world.. Also reduces three queries from database
        // We must return true otherwise exceptions are not shown
        if (is_null(self::$_instance)) {
            return true;
        }

        if (self::$Author) {
            return true;
        } else {
            $username = self::Database()->cleanValue(self::$Cookie->get('username'));
            $password = self::Database()->cleanValue(self::$Cookie->get('pass'));

            if (strlen(trim($username)) > 0 && strlen(trim($password)) > 0) {

                $author = AuthorManager::fetch('id', 'ASC', 1, null, sprintf(
                    "`username` = '%s'",
                    $username
                ));

                if (!empty($author) && Cryptography::compare($password, current($author)->get('password'), true)) {
                    self::$Author = current($author);

                    self::Database()->update(array(
                        'last_seen' => DateTimeObj::get('Y-m-d H:i:s')),
                        'tbl_authors',
                        sprintf(" `id` = %d", self::$Author->get('id'))
                    );

                    // Only set custom author language in the backend
                    if (class_exists('Administration')) {
                        Lang::set(self::$Author->get('language'));
                    }

                    return true;
                }
            }

            return false;
        }
    }

    /**
     * Returns the most recent version found in the `/install/migrations` folder.
     * Returns a version string to be used in `version_compare()` if an updater
     * has been found. Returns `FALSE` otherwise.
     *
     * @since Symphony 2.3.1
     * @return mixed
     */
    public static function getMigrationVersion()
    {
        if (self::isInstallerAvailable()) {
            $migrations = scandir(DOCROOT . '/install/migrations');
            $migration_file = end($migrations);

            include_once DOCROOT . '/install/lib/class.migration.php';
            include_once DOCROOT . '/install/migrations/' . $migration_file;

            $migration_class = 'migration_' . str_replace('.', '', substr($migration_file, 0, -4));
            return call_user_func(array($migration_class, 'getVersion'));
        }

        return false;
    }

    /**
     * Checks if an update is available and applicable for the current installation.
     *
     * @since Symphony 2.3.1
     * @return boolean
     */
    public static function isUpgradeAvailable()
    {
        if (self::isInstallerAvailable()) {
            $migration_version = self::getMigrationVersion();
            $current_version = Symphony::Configuration()->get('version', 'symphony');

            return version_compare($current_version, $migration_version, '<');
        }

        return false;
    }

    /**
     * Checks if the installer/upgrader is available.
     *
     * @since Symphony 2.3.1
     * @return boolean
     */
    public static function isInstallerAvailable()
    {
        return file_exists(DOCROOT . '/install/index.php');
    }

    /**
     * A wrapper for throwing a new Symphony Error page.
     *
     * This methods sets the `GenericExceptionHandler::$enabled` value to `true`.
     *
     * @see core.SymphonyErrorPage
     * @param string|XMLElement $message
     *  A description for this error, which can be provided as a string
     *  or as an XMLElement.
     * @param string $heading
     *  A heading for the error page
     * @param integer $status
     *  Properly sets the HTTP status code for the response. Defaults to
     *  `Page::HTTP_STATUS_ERROR`. Use `Page::HTTP_STATUS_XXX` to set this value.
     * @param string $template
     *  A string for the error page template to use, defaults to 'generic'. This
     *  can be the name of any template file in the `TEMPLATES` directory.
     *  A template using the naming convention of `tpl.*.php`.
     * @param array $additional
     *  Allows custom information to be passed to the Symphony Error Page
     *  that the template may want to expose, such as custom Headers etc.
     * @throws SymphonyErrorPage
     */
    public static function throwCustomError($message, $heading = 'Symphony Fatal Error', $status = Page::HTTP_STATUS_ERROR, $template = 'generic', array $additional = array())
    {
        GenericExceptionHandler::$enabled = true;
        throw new SymphonyErrorPage($message, $heading, $template, $additional, $status);
    }

    /**
     * Setter accepts a previous Exception. Useful for determining the context
     * of a current exception (ie. detecting recursion).
     *
     * @since Symphony 2.3.2
     * @param Exception $ex
     */
    public static function setException(Exception $ex)
    {
        self::$exception = $ex;
    }

    /**
     * Accessor for `self::$exception`.
     *
     * @since Symphony 2.3.2
     * @return Exception|null
     */
    public static function getException()
    {
        return self::$exception;
    }

    /**
     * Returns the page namespace based on the current URL.
     * A few examples:
     *
     * /login
     * /publish
     * /blueprints/datasources
     * [...]
     * /extension/$extension_name/$page_name
     *
     * This method is especially useful in couple with the translation function.
     *
     * @see toolkit#__()
     * @return string
     *  The page namespace, without any action string (e.g. "new", "saved") or
     *  any value that depends upon the single setup (e.g. the section handle in
     *  /publish/$handle)
     */
    public static function getPageNamespace()
    {
        if (self::$namespace !== false) {
            return self::$namespace;
        }

        $page = getCurrentPage();

        if (!is_null($page)) {
            $page = trim($page, '/');
        }

        if (substr($page, 0, 7) == 'publish') {
            self::$namespace = '/publish';
        } elseif (empty($page) && isset($_REQUEST['mode'])) {
            self::$namespace = '/login';
        } elseif (empty($page)) {
            self::$namespace = null;
        } else {
            $bits = explode('/', $page);

            if ($bits[0] == 'extension') {
                self::$namespace = sprintf('/%s/%s/%s', $bits[0], $bits[1], $bits[2]);
            } else {
                self::$namespace =  sprintf('/%s/%s', $bits[0], isset($bits[1]) ? $bits[1] : '');
            }
        }

        return self::$namespace;
    }
}

/**
 * The `SymphonyErrorPageHandler` extends the `GenericExceptionHandler`
 * to allow the template for the exception to be provided from the `TEMPLATES`
 * directory
 */
Class SymphonyErrorPageHandler extends GenericExceptionHandler
{
    /**
     * The render function will take a `SymphonyErrorPage` exception and
     * output a HTML page. This function first checks to see if their is a custom
     * template for this exception otherwise it reverts to using the default
     * `usererror.generic.php`
     *
     * @param Exception $e
     *  The Exception object
     * @return string
     *  An HTML string
     */
    public static function render(Exception $e)
    {
        if ($e->getTemplate() === false) {
            Page::renderStatusCode($e->getHttpStatusCode());

            if (isset($e->getAdditional()->header)) {
                header($e->getAdditional()->header);
            }

            echo '<h1>Symphony Fatal Error</h1><p>'.$e->getMessage().'</p>';
            exit;
        }

        include $e->getTemplate();
    }
}

/**
 * `SymphonyErrorPage` extends the default `Exception` class. All
 * of these exceptions will halt execution immediately and return the
 * exception as a HTML page. By default the HTML template is `usererror.generic.php`
 * from the `TEMPLATES` directory.
 */

Class SymphonyErrorPage extends Exception
{

    /**
     * A heading for the error page, this will be prepended to
     * "Symphony Fatal Error".
     * @return string
     */
    private $_heading;

    /**
     * A string for the error page template to use, defaults to 'generic'. This
     * can be the name of any template file in the `TEMPLATES` directory.
     * A template using the naming convention of `usererror.*.php`.
     * @var string
     */
    private $_template = 'generic';

    /**
     * If the message as provided as an `XMLElement`, it will be saved to
     * this parameter
     * @var XMLElement
     */
    private $_messageObject = null;

    /**
     * An object of an additional information for this error page. Note that
     * this is provided as an array and then typecast to an object
     * @var StdClass
     */
    private $_additional = null;

    /**
     * A simple container for the response status code.
     * Full value is setted usign `$Page->setHttpStatus()`
     * in the template.
     */
    private $_status = Page::HTTP_STATUS_ERROR;

    /**
     * Constructor for SymphonyErrorPage sets it's class variables
     *
     * @param string|XMLElement $message
     *  A description for this error, which can be provided as a string
     *  or as an XMLElement.
     * @param string $heading
     *  A heading for the error page, by default this is "Symphony Fatal Error"
     * @param string $template
     *  A string for the error page template to use, defaults to 'generic'. This
     *  can be the name of any template file in the `TEMPLATES` directory.
     *  A template using the naming convention of `tpl.*.php`.
     * @param array $additional
     *  Allows custom information to be passed to the Symphony Error Page
     *  that the template may want to expose, such as custom Headers etc.
     * @param integer $status
     *  Properly sets the HTTP status code for the response. Defaults to
     *  `Page::HTTP_STATUS_ERROR`
     */
    public function __construct($message, $heading = 'Symphony Fatal Error', $template = 'generic', array $additional = array(), $status = Page::HTTP_STATUS_ERROR)
    {

        if ($message instanceof XMLElement) {
            $this->_messageObject = $message;
            $message = $this->_messageObject->generate();
        }

        parent::__construct($message);

        $this->_heading = $heading;
        $this->_template = $template;
        $this->_additional = (object)$additional;
        $this->_status = $status;
    }

    /**
     * Accessor for the `$_heading` of the error page
     *
     * @return string
     */
    public function getHeading()
    {
        return $this->_heading;
    }

    /**
     * Accessor for `$_messageObject`
     *
     * @return XMLElement
     */
    public function getMessageObject()
    {
        return $this->_messageObject;
    }

    /**
     * Accessor for `$_additional`
     *
     * @return StdClass
     */
    public function getAdditional()
    {
        return $this->_additional;
    }

    /**
     * Accessor for `$_status`
     *
     * @since Symphony 2.3.2
     * @return integer
     */
    public function getHttpStatusCode()
    {
        return $this->_status;
    }

    /**
     * Returns the path to the current template by looking at the
     * `WORKSPACE/template/` directory, then at the `TEMPLATES`
     * directory for the convention `usererror.*.php`. If the template
     * is not found, `false` is returned
     *
     * @since Symphony 2.3
     * @return mixed
     *  String, which is the path to the template if the template is found,
     *  false otherwise
     */
    public function getTemplate()
    {
        $format = '%s/usererror.%s.php';

        if (file_exists($template = sprintf($format, WORKSPACE . '/template', $this->_template))) {
            return $template;
        } elseif (file_exists($template = sprintf($format, TEMPLATE, $this->_template))) {
            return $template;
        } else {
            return false;
        }
    }

    /**
     * A simple getter to the template name in order to be able
     * to identify which type of exception this is.
     *
     * @since Symphony 2.3.2
     * @return string
     */
    public function getTemplateName()
    {
        return $this->_template;
    }
}

/**
 * The `DatabaseExceptionHandler` provides a render function to provide
 * customised output for database exceptions. It displays the exception
 * message as provided by the Database.
 */
Class DatabaseExceptionHandler extends GenericExceptionHandler
{
    /**
     * The render function will take a `DatabaseException` and output a
     * HTML page.
     *
     * @param Exception $e
     *  The Exception object
     * @return string
     *  An HTML string
     */
    public static function render(Exception $e)
    {
        $trace = $queries = null;

        foreach ($e->getTrace() as $t) {
            $trace .= sprintf(
                '<li><code><em>[%s:%d]</em></code></li><li><code>&#160;&#160;&#160;&#160;%s%s%s();</code></li>',
                $t['file'],
                $t['line'],
                (isset($t['class']) ? $t['class'] : null),
                (isset($t['type']) ? $t['type'] : null),
                $t['function']
            );
        }

        if (is_object(Symphony::Database())) {
            $debug = Symphony::Database()->debug();

            if (!empty($debug)) {
                foreach ($debug as $query) {
                    $queries .= sprintf(
                        '<li><em>[%01.4f]</em><code> %s;</code> </li>',
                        (isset($query['execution_time']) ? $query['execution_time'] : null),
                        htmlspecialchars($query['query'])
                    );
                }
            }
        }

        $html = sprintf(
            file_get_contents(self::getTemplate('fatalerror.database')),
            $e->getDatabaseErrorMessage(),
            $e->getQuery(),
            $trace,
            $queries
        );

        $html = str_replace('{APPLICATION_URL}', APPLICATION_URL, $html);
        $html = str_replace('{SYMPHONY_URL}', SYMPHONY_URL, $html);
        $html = str_replace('{URL}', URL, $html);

        return $html;
    }
}