web.php

Aller à la documentation de ce fichier.

<?php
/**
 * @package     Joomla.Platform
 * @subpackage  Application
 *
 * @copyright   Copyright (C) 2005 - 2013 Open Source Matters, Inc. All rights reserved.
 * @license     GNU General Public License version 2 or later; see LICENSE
 */

defined('JPATH_PLATFORM') or die;

/**
 * Base class for a Joomla! Web application.
 *
 * @package     Joomla.Platform
 * @subpackage  Application
 * @since       11.4
 */
class JApplicationWeb extends JApplicationBase
{
        /**
         * @var    string  Character encoding string.
         * @since  11.3
         */
        public $charSet = 'utf-8';

        /**
         * @var    string  Response mime type.
         * @since  11.3
         */
        public $mimeType = 'text/html';

        /**
         * @var    JDate  The body modified date for response headers.
         * @since  11.3
         */
        public $modifiedDate;

        /**
         * @var    JApplicationWebClient  The application client object.
         * @since  11.3
         */
        public $client;

        /**
         * @var    JRegistry  The application configuration object.
         * @since  11.3
         */
        protected $config;

        /**
         * @var    JDocument  The application document object.
         * @since  11.3
         */
        protected $document;

        /**
         * @var    JLanguage  The application language object.
         * @since  11.3
         */
        protected $language;

        /**
         * @var    JSession  The application session object.
         * @since  11.3
         */
        protected $session;

        /**
         * @var    object  The application response object.
         * @since  11.3
         */
        protected $response;

        /**
         * @var    JApplicationWeb  The application instance.
         * @since  11.3
         */
        protected static $instance;

        /**
         * Class constructor.
         *
         * @param   mixed  $input   An optional argument to provide dependency injection for the application's
         *                          input object.  If the argument is a JInput object that object will become
         *                          the application's input object, otherwise a default input object is created.
         * @param   mixed  $config  An optional argument to provide dependency injection for the application's
         *                          config object.  If the argument is a JRegistry object that object will become
         *                          the application's config object, otherwise a default config object is created.
         * @param   mixed  $client  An optional argument to provide dependency injection for the application's
         *                          client object.  If the argument is a JApplicationWebClient object that object will become
         *                          the application's client object, otherwise a default client object is created.
         *
         * @since   11.3
         */
        public function __construct(JInput $input = null, JRegistry $config = null, JApplicationWebClient $client = null)
        {
                // If a input object is given use it.
                if ($input instanceof JInput)
                {
                        $this->input = $input;
                }
                // Create the input based on the application logic.
                else
                {
                        $this->input = new JInput;
                }

                // If a config object is given use it.
                if ($config instanceof JRegistry)
                {
                        $this->config = $config;
                }
                // Instantiate a new configuration object.
                else
                {
                        $this->config = new JRegistry;
                }

                // If a client object is given use it.
                if ($client instanceof JApplicationWebClient)
                {
                        $this->client = $client;
                }
                // Instantiate a new web client object.
                else
                {
                        $this->client = new JApplicationWebClient;
                }

                // Load the configuration object.
                $this->loadConfiguration($this->fetchConfigurationData());

                // Set the execution datetime and timestamp;
                $this->set('execution.datetime', gmdate('Y-m-d H:i:s'));
                $this->set('execution.timestamp', time());

                // Setup the response object.
                $this->response = new stdClass;
                $this->response->cachable = false;
                $this->response->headers = array();
                $this->response->body = array();

                // Set the system URIs.
                $this->loadSystemUris();
        }

        /**
         * Returns a reference to the global JApplicationWeb object, only creating it if it doesn't already exist.
         *
         * This method must be invoked as: $web = JApplicationWeb::getInstance();
         *
         * @param   string  $name  The name (optional) of the JApplicationWeb class to instantiate.
         *
         * @return  JApplicationWeb
         *
         * @since   11.3
         */
        public static function getInstance($name = null)
        {
                // Only create the object if it doesn't exist.
                if (empty(self::$instance))
                {
                        if (class_exists($name) && (is_subclass_of($name, 'JApplicationWeb')))
                        {
                                self::$instance = new $name;
                        }
                        else
                        {
                                self::$instance = new JApplicationWeb;
                        }
                }

                return self::$instance;
        }

        /**
         * Initialise the application.
         *
         * @param   mixed  $session     An optional argument to provide dependency injection for the application's
         *                              session object.  If the argument is a JSession object that object will become
         *                              the application's session object, if it is false then there will be no session
         *                              object, and if it is null then the default session object will be created based
         *                              on the application's loadSession() method.
         * @param   mixed  $document    An optional argument to provide dependency injection for the application's
         *                              document object.  If the argument is a JDocument object that object will become
         *                              the application's document object, if it is false then there will be no document
         *                              object, and if it is null then the default document object will be created based
         *                              on the application's loadDocument() method.
         * @param   mixed  $language    An optional argument to provide dependency injection for the application's
         *                              language object.  If the argument is a JLanguage object that object will become
         *                              the application's language object, if it is false then there will be no language
         *                              object, and if it is null then the default language object will be created based
         *                              on the application's loadLanguage() method.
         * @param   mixed  $dispatcher  An optional argument to provide dependency injection for the application's
         *                              event dispatcher.  If the argument is a JEventDispatcher object that object will become
         *                              the application's event dispatcher, if it is null then the default event dispatcher
         *                              will be created based on the application's loadDispatcher() method.
         *
         * @return  JApplicationWeb  Instance of $this to allow chaining.
         *
         * @deprecated  13.1 (Platform) & 4.0 (CMS)
         * @see     JApplicationWeb::loadSession()
         * @see     JApplicationWeb::loadDocument()
         * @see     JApplicationWeb::loadLanguage()
         * @see     JApplicationBase::loadDispatcher()
         * @since   11.3
         */
        public function initialise($session = null, $document = null, $language = null, $dispatcher = null)
        {
                // Create the session based on the application logic.
                if ($session !== false)
                {
                        $this->loadSession($session);
                }

                // Create the document based on the application logic.
                if ($document !== false)
                {
                        $this->loadDocument($document);
                }

                // Create the language based on the application logic.
                if ($language !== false)
                {
                        $this->loadLanguage($language);
                }

                $this->loadDispatcher($dispatcher);

                return $this;
        }

        /**
         * Execute the application.
         *
         * @return  void
         *
         * @since   11.3
         */
        public function execute()
        {
                // Trigger the onBeforeExecute event.
                $this->triggerEvent('onBeforeExecute');

                // Perform application routines.
                $this->doExecute();

                // Trigger the onAfterExecute event.
                $this->triggerEvent('onAfterExecute');

                // If we have an application document object, render it.
                if ($this->document instanceof JDocument)
                {
                        // Trigger the onBeforeRender event.
                        $this->triggerEvent('onBeforeRender');

                        // Render the application output.
                        $this->render();

                        // Trigger the onAfterRender event.
                        $this->triggerEvent('onAfterRender');
                }

                // If gzip compression is enabled in configuration and the server is compliant, compress the output.
                if ($this->get('gzip') && !ini_get('zlib.output_compression') && (ini_get('output_handler') != 'ob_gzhandler'))
                {
                        $this->compress();
                }

                // Trigger the onBeforeRespond event.
                $this->triggerEvent('onBeforeRespond');

                // Send the application response.
                $this->respond();

                // Trigger the onAfterRespond event.
                $this->triggerEvent('onAfterRespond');
        }

        /**
         * Method to run the Web application routines.  Most likely you will want to instantiate a controller
         * and execute it, or perform some sort of action that populates a JDocument object so that output
         * can be rendered to the client.
         *
         * @return  void
         *
         * @codeCoverageIgnore
         * @since   11.3
         */
        protected function doExecute()
        {
                // Your application routines go here.
        }

        /**
         * Rendering is the process of pushing the document buffers into the template
         * placeholders, retrieving data from the document and pushing it into
         * the application response buffer.
         *
         * @return  void
         *
         * @since   11.3
         */
        protected function render()
        {
                // Setup the document options.
                $options = array(
                        'template' => $this->get('theme'),
                        'file' => $this->get('themeFile', 'index.php'),
                        'params' => $this->get('themeParams')
                );

                if ($this->get('themes.base'))
                {
                        $options['directory'] = $this->get('themes.base');
                }
                // Fall back to constants.
                else
                {
                        $options['directory'] = defined('JPATH_THEMES') ? JPATH_THEMES : (defined('JPATH_BASE') ? JPATH_BASE : __DIR__) . '/themes';
                }

                // Parse the document.
                $this->document->parse($options);

                // Render the document.
                $data = $this->document->render($this->get('cache_enabled'), $options);

                // Set the application output data.
                $this->setBody($data);
        }

        /**
         * Checks the accept encoding of the browser and compresses the data before
         * sending it to the client if possible.
         *
         * @return  void
         *
         * @since   11.3
         */
        protected function compress()
        {
                // Supported compression encodings.
                $supported = array(
                        'x-gzip' => 'gz',
                        'gzip' => 'gz',
                        'deflate' => 'deflate'
                );

                // Get the supported encoding.
                $encodings = array_intersect($this->client->encodings, array_keys($supported));

                // If no supported encoding is detected do nothing and return.
                if (empty($encodings))
                {
                        return;
                }

                // Verify that headers have not yet been sent, and that our connection is still alive.
                if ($this->checkHeadersSent() || !$this->checkConnectionAlive())
                {
                        return;
                }

                // Iterate through the encodings and attempt to compress the data using any found supported encodings.
                foreach ($encodings as $encoding)
                {
                        if (($supported[$encoding] == 'gz') || ($supported[$encoding] == 'deflate'))
                        {
                                // Verify that the server supports gzip compression before we attempt to gzip encode the data.
                                // @codeCoverageIgnoreStart
                                if (!extension_loaded('zlib') || ini_get('zlib.output_compression'))
                                {
                                        continue;
                                }
                                // @codeCoverageIgnoreEnd

                                // Attempt to gzip encode the data with an optimal level 4.
                                $data = $this->getBody();
                                $gzdata = gzencode($data, 4, ($supported[$encoding] == 'gz') ? FORCE_GZIP : FORCE_DEFLATE);

                                // If there was a problem encoding the data just try the next encoding scheme.
                                // @codeCoverageIgnoreStart
                                if ($gzdata === false)
                                {
                                        continue;
                                }
                                // @codeCoverageIgnoreEnd

                                // Set the encoding headers.
                                $this->setHeader('Content-Encoding', $encoding);

                                // Header will be removed at 4.0
                                if ($this->get('MetaVersion'))
                                {
                                        $this->setHeader('X-Content-Encoded-By', 'Joomla');
                                }

                                // Replace the output with the encoded data.
                                $this->setBody($gzdata);

                                // Compression complete, let's break out of the loop.
                                break;
                        }
                }
        }

        /**
         * Method to send the application response to the client.  All headers will be sent prior to the main
         * application output data.
         *
         * @return  void
         *
         * @since   11.3
         */
        protected function respond()
        {
                // Send the content-type header.
                $this->setHeader('Content-Type', $this->mimeType . '; charset=' . $this->charSet);

                // If the response is set to uncachable, we need to set some appropriate headers so browsers don't cache the response.
                if (!$this->response->cachable)
                {
                        // Expires in the past.
                        $this->setHeader('Expires', 'Mon, 1 Jan 2001 00:00:00 GMT', true);

                        // Always modified.
                        $this->setHeader('Last-Modified', gmdate('D, d M Y H:i:s') . ' GMT', true);
                        $this->setHeader('Cache-Control', 'no-store, no-cache, must-revalidate, post-check=0, pre-check=0', false);

                        // HTTP 1.0
                        $this->setHeader('Pragma', 'no-cache');
                }
                else
                {
                        // Expires.
                        $this->setHeader('Expires', gmdate('D, d M Y H:i:s', time() + 900) . ' GMT');

                        // Last modified.
                        if ($this->modifiedDate instanceof JDate)
                        {
                                $this->setHeader('Last-Modified', $this->modifiedDate->format('D, d M Y H:i:s'));
                        }
                }

                $this->sendHeaders();

                echo $this->getBody();
        }

        /**
         * Redirect to another URL.
         *
         * If the headers have not been sent the redirect will be accomplished using a "301 Moved Permanently"
         * or "303 See Other" code in the header pointing to the new location. If the headers have already been
         * sent this will be accomplished using a JavaScript statement.
         *
         * @param   string   $url    The URL to redirect to. Can only be http/https URL
         * @param   boolean  $moved  True if the page is 301 Permanently Moved, otherwise 303 See Other is assumed.
         *
         * @return  void
         *
         * @since   11.3
         */
        public function redirect($url, $moved = false)
        {
                // Import library dependencies.
                jimport('phputf8.utils.ascii');

                // Check for relative internal links.
                if (preg_match('#^index\.php#', $url))
                {
                        // We changed this from "$this->get('uri.base.full') . $url" due to the inability to run the system tests with the original code
                        $url = JUri::base() . $url;
                }

                // Perform a basic sanity check to make sure we don't have any CRLF garbage.
                $url = preg_split("/[\r\n]/", $url);
                $url = $url[0];

                /*
                 * Here we need to check and see if the URL is relative or absolute.  Essentially, do we need to
                 * prepend the URL with our base URL for a proper redirect.  The rudimentary way we are looking
                 * at this is to simply check whether or not the URL string has a valid scheme or not.
                 */
                if (!preg_match('#^[a-z]+\://#i', $url))
                {
                        // Get a JUri instance for the requested URI.
                        $uri = JUri::getInstance($this->get('uri.request'));

                        // Get a base URL to prepend from the requested URI.
                        $prefix = $uri->toString(array('scheme', 'user', 'pass', 'host', 'port'));

                        // We just need the prefix since we have a path relative to the root.
                        if ($url[0] == '/')
                        {
                                $url = $prefix . $url;
                        }
                        // It's relative to where we are now, so lets add that.
                        else
                        {
                                $parts = explode('/', $uri->toString(array('path')));
                                array_pop($parts);
                                $path = implode('/', $parts) . '/';
                                $url = $prefix . $path . $url;
                        }
                }

                // If the headers have already been sent we need to send the redirect statement via JavaScript.
                if ($this->checkHeadersSent())
                {
                        echo "<script>document.location.href='" . str_replace("'", "&apos;", $url) . "';</script>\n";
                }
                else
                {
                        // We have to use a JavaScript redirect here because MSIE doesn't play nice with utf-8 URLs.
                        if (($this->client->engine == JApplicationWebClient::TRIDENT) && !utf8_is_ascii($url))
                        {
                                $html = '<html><head>';
                                $html .= '<meta http-equiv="content-type" content="text/html; charset=' . $this->charSet . '" />';
                                $html .= '<script>document.location.href=\'' . str_replace("'", "&apos;", $url) . '\';</script>';
                                $html .= '</head><body></body></html>';

                                echo $html;
                        }
                        else
                        {
                                // All other cases use the more efficient HTTP header for redirection.
                                $this->header($moved ? 'HTTP/1.1 301 Moved Permanently' : 'HTTP/1.1 303 See other');
                                $this->header('Location: ' . $url);
                                $this->header('Content-Type: text/html; charset=' . $this->charSet);
                        }
                }

                // Close the application after the redirect.
                $this->close();
        }

        /**
         * Load an object or array into the application configuration object.
         *
         * @param   mixed  $data  Either an array or object to be loaded into the configuration object.
         *
         * @return  JApplicationWeb  Instance of $this to allow chaining.
         *
         * @since   11.3
         */
        public function loadConfiguration($data)
        {
                // Load the data into the configuration object.
                if (is_array($data))
                {
                        $this->config->loadArray($data);
                }
                elseif (is_object($data))
                {
                        $this->config->loadObject($data);
                }

                return $this;
        }

        /**
         * Returns a property of the object or the default value if the property is not set.
         *
         * @param   string  $key      The name of the property.
         * @param   mixed   $default  The default value (optional) if none is set.
         *
         * @return  mixed   The value of the configuration.
         *
         * @since   11.3
         */
        public function get($key, $default = null)
        {
                return $this->config->get($key, $default);
        }

        /**
         * Modifies a property of the object, creating it if it does not already exist.
         *
         * @param   string  $key    The name of the property.
         * @param   mixed   $value  The value of the property to set (optional).
         *
         * @return  mixed   Previous value of the property
         *
         * @since   11.3
         */
        public function set($key, $value = null)
        {
                $previous = $this->config->get($key);
                $this->config->set($key, $value);

                return $previous;
        }

        /**
         * Set/get cachable state for the response.  If $allow is set, sets the cachable state of the
         * response.  Always returns the current state.
         *
         * @param   boolean  $allow  True to allow browser caching.
         *
         * @return  boolean
         *
         * @since   11.3
         */
        public function allowCache($allow = null)
        {
                if ($allow !== null)
                {
                        $this->response->cachable = (bool) $allow;
                }

                return $this->response->cachable;
        }

        /**
         * Method to set a response header.  If the replace flag is set then all headers
         * with the given name will be replaced by the new one.  The headers are stored
         * in an internal array to be sent when the site is sent to the browser.
         *
         * @param   string   $name     The name of the header to set.
         * @param   string   $value    The value of the header to set.
         * @param   boolean  $replace  True to replace any headers with the same name.
         *
         * @return  JApplicationWeb  Instance of $this to allow chaining.
         *
         * @since   11.3
         */
        public function setHeader($name, $value, $replace = false)
        {
                // Sanitize the input values.
                $name = (string) $name;
                $value = (string) $value;

                // If the replace flag is set, unset all known headers with the given name.
                if ($replace)
                {
                        foreach ($this->response->headers as $key => $header)
                        {
                                if ($name == $header['name'])
                                {
                                        unset($this->response->headers[$key]);
                                }
                        }

                        // Clean up the array as unsetting nested arrays leaves some junk.
                        $this->response->headers = array_values($this->response->headers);
                }

                // Add the header to the internal array.
                $this->response->headers[] = array('name' => $name, 'value' => $value);

                return $this;
        }

        /**
         * Method to get the array of response headers to be sent when the response is sent
         * to the client.
         *
         * @return  array
         *
         * @since   11.3
         */
        public function getHeaders()
        {
                return $this->response->headers;
        }

        /**
         * Method to clear any set response headers.
         *
         * @return  JApplicationWeb  Instance of $this to allow chaining.
         *
         * @since   11.3
         */
        public function clearHeaders()
        {
                $this->response->headers = array();

                return $this;
        }

        /**
         * Send the response headers.
         *
         * @return  JApplicationWeb  Instance of $this to allow chaining.
         *
         * @since   11.3
         */
        public function sendHeaders()
        {
                if (!$this->checkHeadersSent())
                {
                        foreach ($this->response->headers as $header)
                        {
                                if ('status' == strtolower($header['name']))
                                {
                                        // 'status' headers indicate an HTTP status, and need to be handled slightly differently
                                        $this->header(ucfirst(strtolower($header['name'])) . ': ' . $header['value'], null, (int) $header['value']);
                                }
                                else
                                {
                                        $this->header($header['name'] . ': ' . $header['value']);
                                }
                        }
                }

                return $this;
        }

        /**
         * Set body content.  If body content already defined, this will replace it.
         *
         * @param   string  $content  The content to set as the response body.
         *
         * @return  JApplicationWeb  Instance of $this to allow chaining.
         *
         * @since   11.3
         */
        public function setBody($content)
        {
                $this->response->body = array((string) $content);

                return $this;
        }

        /**
         * Prepend content to the body content
         *
         * @param   string  $content  The content to prepend to the response body.
         *
         * @return  JApplicationWeb  Instance of $this to allow chaining.
         *
         * @since   11.3
         */
        public function prependBody($content)
        {
                array_unshift($this->response->body, (string) $content);

                return $this;
        }

        /**
         * Append content to the body content
         *
         * @param   string  $content  The content to append to the response body.
         *
         * @return  JApplicationWeb  Instance of $this to allow chaining.
         *
         * @since   11.3
         */
        public function appendBody($content)
        {
                array_push($this->response->body, (string) $content);

                return $this;
        }

        /**
         * Return the body content
         *
         * @param   boolean  $asArray  True to return the body as an array of strings.
         *
         * @return  mixed  The response body either as an array or concatenated string.
         *
         * @since   11.3
         */
        public function getBody($asArray = false)
        {
                return $asArray ? $this->response->body : implode((array) $this->response->body);
        }

        /**
         * Method to get the application document object.
         *
         * @return  JDocument  The document object
         *
         * @since   11.3
         */
        public function getDocument()
        {
                return $this->document;
        }

        /**
         * Method to get the application language object.
         *
         * @return  JLanguage  The language object
         *
         * @since   11.3
         */
        public function getLanguage()
        {
                return $this->language;
        }

        /**
         * Method to get the application session object.
         *
         * @return  JSession  The session object
         *
         * @since   11.3
         */
        public function getSession()
        {
                return $this->session;
        }

        /**
         * Method to check the current client connnection status to ensure that it is alive.  We are
         * wrapping this to isolate the connection_status() function from our code base for testing reasons.
         *
         * @return  boolean  True if the connection is valid and normal.
         *
         * @codeCoverageIgnore
         * @see     connection_status()
         * @since   11.3
         */
        protected function checkConnectionAlive()
        {
                return (connection_status() === CONNECTION_NORMAL);
        }

        /**
         * Method to check to see if headers have already been sent.  We are wrapping this to isolate the
         * headers_sent() function from our code base for testing reasons.
         *
         * @return  boolean  True if the headers have already been sent.
         *
         * @codeCoverageIgnore
         * @see     headers_sent()
         * @since   11.3
         */
        protected function checkHeadersSent()
        {
                return headers_sent();
        }

        /**
         * Method to detect the requested URI from server environment variables.
         *
         * @return  string  The requested URI
         *
         * @since   11.3
         */
        protected function detectRequestUri()
        {
                // First we need to detect the URI scheme.
                if (isset($_SERVER['HTTPS']) && !empty($_SERVER['HTTPS']) && (strtolower($_SERVER['HTTPS']) != 'off'))
                {
                        $scheme = 'https://';
                }
                else
                {
                        $scheme = 'http://';
                }

                /*
                 * There are some differences in the way that Apache and IIS populate server environment variables.  To
                 * properly detect the requested URI we need to adjust our algorithm based on whether or not we are getting
                 * information from Apache or IIS.
                 */

                // If PHP_SELF and REQUEST_URI are both populated then we will assume "Apache Mode".
                if (!empty($_SERVER['PHP_SELF']) && !empty($_SERVER['REQUEST_URI']))
                {
                        // The URI is built from the HTTP_HOST and REQUEST_URI environment variables in an Apache environment.
                        $uri = $scheme . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];
                }
                // If not in "Apache Mode" we will assume that we are in an IIS environment and proceed.
                else
                {
                        // IIS uses the SCRIPT_NAME variable instead of a REQUEST_URI variable... thanks, MS
                        $uri = $scheme . $_SERVER['HTTP_HOST'] . $_SERVER['SCRIPT_NAME'];

                        // If the QUERY_STRING variable exists append it to the URI string.
                        if (isset($_SERVER['QUERY_STRING']) && !empty($_SERVER['QUERY_STRING']))
                        {
                                $uri .= '?' . $_SERVER['QUERY_STRING'];
                        }
                }

                return trim($uri);
        }

        /**
         * Method to load a PHP configuration class file based on convention and return the instantiated data object.  You
         * will extend this method in child classes to provide configuration data from whatever data source is relevant
         * for your specific application.
         *
         * @param   string  $file   The path and filename of the configuration file. If not provided, configuration.php
         *                          in JPATH_BASE will be used.
         * @param   string  $class  The class name to instantiate.
         *
         * @return  mixed   Either an array or object to be loaded into the configuration object.
         *
         * @since   11.3
         * @throws  RuntimeException
         */
        protected function fetchConfigurationData($file = '', $class = 'JConfig')
        {
                // Instantiate variables.
                $config = array();

                if (empty($file) && defined('JPATH_ROOT'))
                {
                        $file = JPATH_ROOT . '/configuration.php';

                        // Applications can choose not to have any configuration data
                        // by not implementing this method and not having a config file.
                        if (!file_exists($file))
                        {
                                $file = '';
                        }
                }

                if (!empty($file))
                {
                        JLoader::register($class, $file);

                        if (class_exists($class))
                        {
                                $config = new $class;
                        }
                        else
                        {
                                throw new RuntimeException('Configuration class does not exist.');
                        }
                }

                return $config;
        }

        /**
         * Flush the media version to refresh versionable assets
         *
         * @return  void
         *
         * @since   3.2
         */
        public function flushAssets()
        {
                $version = new JVersion;
                $version->refreshMediaVersion();
        }

        /**
         * Method to send a header to the client.  We are wrapping this to isolate the header() function
         * from our code base for testing reasons.
         *
         * @param   string   $string   The header string.
         * @param   boolean  $replace  The optional replace parameter indicates whether the header should
         *                             replace a previous similar header, or add a second header of the same type.
         * @param   integer  $code     Forces the HTTP response code to the specified value. Note that
         *                             this parameter only has an effect if the string is not empty.
         *
         * @return  void
         *
         * @codeCoverageIgnore
         * @see     header()
         * @since   11.3
         */
        protected function header($string, $replace = true, $code = null)
        {
                header($string, $replace, $code);
        }

        /**
         * Determine if we are using a secure (SSL) connection.
         *
         * @return  boolean  True if using SSL, false if not.
         *
         * @since   12.2
         */
        public function isSSLConnection()
        {
                return ((isset($_SERVER['HTTPS']) && ($_SERVER['HTTPS'] == 'on')) || getenv('SSL_PROTOCOL_VERSION'));
        }

        /**
         * Allows the application to load a custom or default document.
         *
         * The logic and options for creating this object are adequately generic for default cases
         * but for many applications it will make sense to override this method and create a document,
         * if required, based on more specific needs.
         *
         * @param   JDocument  $document  An optional document object. If omitted, the factory document is created.
         *
         * @return  JApplicationWeb This method is chainable.
         *
         * @since   11.3
         */
        public function loadDocument(JDocument $document = null)
        {
                $this->document = ($document === null) ? JFactory::getDocument() : $document;

                return $this;
        }

        /**
         * Allows the application to load a custom or default language.
         *
         * The logic and options for creating this object are adequately generic for default cases
         * but for many applications it will make sense to override this method and create a language,
         * if required, based on more specific needs.
         *
         * @param   JLanguage  $language  An optional language object. If omitted, the factory language is created.
         *
         * @return  JApplicationWeb This method is chainable.
         *
         * @since   11.3
         */
        public function loadLanguage(JLanguage $language = null)
        {
                $this->language = ($language === null) ? JFactory::getLanguage() : $language;

                return $this;
        }

        /**
         * Allows the application to load a custom or default session.
         *
         * The logic and options for creating this object are adequately generic for default cases
         * but for many applications it will make sense to override this method and create a session,
         * if required, based on more specific needs.
         *
         * @param   JSession  $session  An optional session object. If omitted, the session is created.
         *
         * @return  JApplicationWeb This method is chainable.
         *
         * @since   11.3
         */
        public function loadSession(JSession $session = null)
        {
                if ($session !== null)
                {
                        $this->session = $session;

                        return $this;
                }

                // Generate a session name.
                $name = md5($this->get('secret') . $this->get('session_name', get_class($this)));

                // Calculate the session lifetime.
                $lifetime = (($this->get('sess_lifetime')) ? $this->get('sess_lifetime') * 60 : 900);

                // Get the session handler from the configuration.
                $handler = $this->get('sess_handler', 'none');

                // Initialize the options for JSession.
                $options = array(
                        'name' => $name,
                        'expire' => $lifetime,
                        'force_ssl' => $this->get('force_ssl')
                );

                $this->registerEvent('onAfterSessionStart', array($this, 'afterSessionStart'));

                // Instantiate the session object.
                $session = JSession::getInstance($handler, $options);
                $session->initialise($this->input, $this->dispatcher);

                if ($session->getState() == 'expired')
                {
                        $session->restart();
                }
                else
                {
                        $session->start();
                }

                // Set the session object.
                $this->session = $session;

                return $this;
        }

        /**
         * After the session has been started we need to populate it with some default values.
         *
         * @return  void
         *
         * @since   12.2
         */
        public function afterSessionStart()
        {
                $session = JFactory::getSession();

                if ($session->isNew())
                {
                        $session->set('registry', new JRegistry('session'));
                        $session->set('user', new JUser);
                }
        }

        /**
         * Method to load the system URI strings for the application.
         *
         * @param   string  $requestUri  An optional request URI to use instead of detecting one from the
         *                               server environment variables.
         *
         * @return  void
         *
         * @since   11.3
         */
        protected function loadSystemUris($requestUri = null)
        {
                // Set the request URI.
                // @codeCoverageIgnoreStart
                if (!empty($requestUri))
                {
                        $this->set('uri.request', $requestUri);
                }
                else
                {
                        $this->set('uri.request', $this->detectRequestUri());
                }
                // @codeCoverageIgnoreEnd

                // Check to see if an explicit base URI has been set.
                $siteUri = trim($this->get('site_uri'));

                if ($siteUri != '')
                {
                        $uri = JUri::getInstance($siteUri);
                }
                // No explicit base URI was set so we need to detect it.
                else
                {
                        // Start with the requested URI.
                        $uri = JUri::getInstance($this->get('uri.request'));

                        // If we are working from a CGI SAPI with the 'cgi.fix_pathinfo' directive disabled we use PHP_SELF.
                        if (strpos(php_sapi_name(), 'cgi') !== false && !ini_get('cgi.fix_pathinfo') && !empty($_SERVER['REQUEST_URI']))
                        {
                                // We aren't expecting PATH_INFO within PHP_SELF so this should work.
                                $uri->setPath(rtrim(dirname($_SERVER['PHP_SELF']), '/\\'));
                        }
                        // Pretty much everything else should be handled with SCRIPT_NAME.
                        else
                        {
                                $uri->setPath(rtrim(dirname($_SERVER['SCRIPT_NAME']), '/\\'));
                        }

                        // Clear the unused parts of the requested URI.
                        $uri->setQuery(null);
                        $uri->setFragment(null);
                }

                // Get the host and path from the URI.
                $host = $uri->toString(array('scheme', 'user', 'pass', 'host', 'port'));
                $path = rtrim($uri->toString(array('path')), '/\\');

                // Check if the path includes "index.php".
                if (strpos($path, 'index.php') !== false)
                {
                        // Remove the index.php portion of the path.
                        $path = substr_replace($path, '', strpos($path, 'index.php'), 9);
                        $path = rtrim($path, '/\\');
                }

                // Set the base URI both as just a path and as the full URI.
                $this->set('uri.base.full', $host . $path . '/');
                $this->set('uri.base.host', $host);
                $this->set('uri.base.path', $path . '/');

                // Set the extended (non-base) part of the request URI as the route.
                $this->set('uri.route', substr_replace($this->get('uri.request'), '', 0, strlen($this->get('uri.base.full'))));

                // Get an explicitly set media URI is present.
                $mediaURI = trim($this->get('media_uri'));

                if ($mediaURI)
                {
                        if (strpos($mediaURI, '://') !== false)
                        {
                                $this->set('uri.media.full', $mediaURI);
                                $this->set('uri.media.path', $mediaURI);
                        }
                        else
                        {
                                // Normalise slashes.
                                $mediaURI = trim($mediaURI, '/\\');
                                $mediaURI = !empty($mediaURI) ? '/' . $mediaURI . '/' : '/';
                                $this->set('uri.media.full', $this->get('uri.base.host') . $mediaURI);
                                $this->set('uri.media.path', $mediaURI);
                        }
                }
                // No explicit media URI was set, build it dynamically from the base uri.
                else
                {
                        $this->set('uri.media.full', $this->get('uri.base.full') . 'media/');
                        $this->set('uri.media.path', $this->get('uri.base.path') . 'media/');
                }
        }
}