Saving Data * * You can write a value to a users session from your PHP code using the static function {@link Session::set()}. You * can add this line in any function or file you wish to save the value. * * * Session::set('MyValue', 6); * * * Saves the value of "6" to the MyValue session data. You can also save arrays or serialized objects in session (but * note there may be size restrictions as to how much you can save) * * * // save a variable * $var = 1; * Session::set('MyVar', $var); * * // saves an array * Session::set('MyArrayOfValues', array('1', '2', '3')); * * // saves an object (you'll have to unserialize it back) * $object = new Object(); * * Session::set('MyObject', serialize($object)); * * * Accessing Data * * Once you have saved a value to the Session you can access it by using the {@link Session::get()} function. * Like the {@link Session::set()} function you can use this anywhere in your PHP files. * Note that session data isn't persisted in PHP's own session store (via $_SESSION) * until {@link Session::save()} is called, which happens automatically at the end of a standard request * through {@link SilverStripe\Control\Middleware\SessionMiddleware}. * * The values in the comments are the values stored from the previous example. * * * public function bar() { * $value = Session::get('MyValue'); // $value = 6 * $var = Session::get('MyVar'); // $var = 1 * $array = Session::get('MyArrayOfValues'); // $array = array(1,2,3) * $object = Session::get('MyObject', unserialize($object)); // $object = Object() * } * * * You can also get all the values in the session at once. This is useful for debugging. * * * Session::get_all(); // returns an array of all the session values. * * * Clearing Data * * Once you have accessed a value from the Session it doesn't automatically wipe the value from the Session, you have * to specifically remove it. To clear a value you can either delete 1 session value by the name that you saved it * * * Session::clear('MyValue'); // MyValue is no longer 6. * * * Or you can clear every single value in the session at once. Note SilverStripe stores some of its own session data * including form and page comment information. None of this is vital but clear_all will clear everything. * * * Session::clear_all(); * * * @see Cookie */ class Session { use Configurable; /** * Set session timeout in seconds. * * @var int * @config */ private static $timeout = 0; /** * @config * @var array */ private static $session_ips = array(); /** * @config * @var string */ private static $cookie_domain; /** * @config * @var string */ private static $cookie_path; /** * @config * @var string */ private static $session_store_path; /** * @config * @var boolean */ private static $cookie_secure = false; /** * @config * @var string */ private static $cookie_name_secure = 'SECSESSID'; /** * Name of session cache limiter to use. * Defaults to '' to disable cache limiter entirely. * * @see https://secure.php.net/manual/en/function.session-cache-limiter.php * @var string|null */ private static $sessionCacheLimiter = ''; /** * Session data. * Will be null if session has not been started * * @var array|null */ protected $data = null; /** * @var bool */ protected $started = false; /** * List of keys changed. This is a nested array which represents the * keys modified in $this->data. The value of each item is either "true" * or a nested array. * * If a value is in changedData but not in data, it must be removed * from the destination during save(). * * Only highest level changes are stored. E.g. changes to `Base.Sub` * and then `Base` only records `Base` as the change. * * E.g. * [ * 'Base' => true, * 'Key' => [ * 'Nested' => true, * ], * ] * * @var array */ protected $changedData = array(); /** * Get user agent for this request * * @param HTTPRequest $request * @return string */ protected function userAgent(HTTPRequest $request) { return $request->getHeader('User-Agent'); } /** * Start PHP session, then create a new Session object with the given start data. * * @param array|null|Session $data Can be an array of data (such as $_SESSION) or another Session object to clone. * If null, this session is treated as unstarted. */ public function __construct($data) { if ($data instanceof Session) { $data = $data->getAll(); } $this->data = $data; $this->started = isset($data); } /** * Init this session instance before usage, * if a session identifier is part of the passed in request. * Otherwise, a session might be started in {@link save()} * if session data needs to be written with a new session identifier. * * @param HTTPRequest $request */ public function init(HTTPRequest $request) { if (!$this->isStarted() && $this->requestContainsSessionId($request)) { $this->start($request); } // Funny business detected! if (isset($this->data['HTTP_USER_AGENT'])) { if ($this->data['HTTP_USER_AGENT'] !== $this->userAgent($request)) { $this->clearAll(); $this->destroy(); $this->started = false; $this->start($request); } } } /** * Destroy existing session and restart * * @param HTTPRequest $request */ public function restart(HTTPRequest $request) { $this->destroy(); $this->init($request); } /** * Determine if this session has started * * @return bool */ public function isStarted() { return $this->started; } /** * @param HTTPRequest $request * @return bool */ public function requestContainsSessionId(HTTPRequest $request) { $secure = Director::is_https($request) && $this->config()->get('cookie_secure'); $name = $secure ? $this->config()->get('cookie_name_secure') : session_name(); return (bool)Cookie::get($name); } /** * Begin session, regardless if a session identifier is present in the request, * or whether any session data needs to be written. * See {@link init()} if you want to "lazy start" a session. * * @param HTTPRequest $request The request for which to start a session */ public function start(HTTPRequest $request) { if ($this->isStarted()) { throw new BadMethodCallException("Session has already started"); } $path = $this->config()->get('cookie_path'); if (!$path) { $path = Director::baseURL(); } $domain = $this->config()->get('cookie_domain'); $secure = Director::is_https($request) && $this->config()->get('cookie_secure'); $session_path = $this->config()->get('session_store_path'); $timeout = $this->config()->get('timeout'); // Director::baseURL can return absolute domain names - this extracts the relevant parts // for the session otherwise we can get broken session cookies if (Director::is_absolute_url($path)) { $urlParts = parse_url($path); $path = $urlParts['path']; if (!$domain) { $domain = $urlParts['host']; } } // If the session cookie is already set, then the session can be read even if headers_sent() = true // This helps with edge-case such as debugging. $data = []; if (!session_id() && (!headers_sent() || $this->requestContainsSessionId($request))) { if (!headers_sent()) { session_set_cookie_params($timeout ?: 0, $path, $domain ?: null, $secure, true); $limiter = $this->config()->get('sessionCacheLimiter'); if (isset($limiter)) { session_cache_limiter($limiter); } // Allow storing the session in a non standard location if ($session_path) { session_save_path($session_path); } // If we want a secure cookie for HTTPS, use a separate session name. This lets us have a // separate (less secure) session for non-HTTPS requests // if headers_sent() is true then it's best to throw the resulting error rather than risk // a security hole. if ($secure) { session_name($this->config()->get('cookie_name_secure')); } session_start(); } else { // If headers are sent then we can't have a session_cache_limiter otherwise we'll get a warning session_cache_limiter(null); } if (isset($_SESSION)) { // Initialise data from session store if present $data = $_SESSION; // Merge in existing in-memory data, taking priority over session store data $this->recursivelyApply((array)$this->data, $data); } } // Save any modified session data back to the session store if present, otherwise initialise it to an array. $this->data = $data; $this->started = true; } /** * Destroy this session * * @param bool $removeCookie */ public function destroy($removeCookie = true) { if (session_id()) { if ($removeCookie) { $path = $this->config()->get('cookie_path') ?: Director::baseURL(); $domain = $this->config()->get('cookie_domain'); $secure = $this->config()->get('cookie_secure'); Cookie::force_expiry(session_name(), $path, $domain, $secure, true); } session_destroy(); } // Clean up the superglobal - session_destroy does not do it. // http://nz1.php.net/manual/en/function.session-destroy.php unset($_SESSION); $this->data = null; } /** * Set session value * * @param string $name * @param mixed $val * @return $this */ public function set($name, $val) { $var = &$this->nestedValueRef($name, $this->data); // Mark changed if ($var !== $val) { $var = $val; $this->markChanged($name); } return $this; } /** * Mark key as changed * * @internal * @param string $name */ protected function markChanged($name) { $diffVar = &$this->changedData; foreach (explode('.', $name) as $namePart) { if (!isset($diffVar[$namePart])) { $diffVar[$namePart] = []; } $diffVar = &$diffVar[$namePart]; // Already diffed if ($diffVar === true) { return; } } // Mark changed $diffVar = true; } /** * Merge value with array * * @param string $name * @param mixed $val */ public function addToArray($name, $val) { $names = explode('.', $name); // We still want to do this even if we have strict path checking for legacy code $var = &$this->data; $diffVar = &$this->changedData; foreach ($names as $n) { $var = &$var[$n]; $diffVar = &$diffVar[$n]; } $var[] = $val; $diffVar[sizeof($var) - 1] = $val; } /** * Get session value * * @param string $name * @return mixed */ public function get($name) { return $this->nestedValue($name, $this->data); } /** * Clear session value * * @param string $name * @return $this */ public function clear($name) { // Get var by path $var = $this->nestedValue($name, $this->data); // Unset var if ($var !== null) { // Unset parent key $parentParts = explode('.', $name); $basePart = array_pop($parentParts); if ($parentParts) { $parent = &$this->nestedValueRef(implode('.', $parentParts), $this->data); unset($parent[$basePart]); } else { unset($this->data[$name]); } $this->markChanged($name); } return $this; } /** * Clear all values */ public function clearAll() { if ($this->data && is_array($this->data)) { foreach (array_keys($this->data) as $key) { $this->clear($key); } } } /** * Get all values * * @return array|null */ public function getAll() { return $this->data; } /** * Set user agent key * * @param HTTPRequest $request */ public function finalize(HTTPRequest $request) { $this->set('HTTP_USER_AGENT', $this->userAgent($request)); } /** * Save data to session * Only save the changes, so that anyone manipulating $_SESSION directly doesn't get burned. * * @param HTTPRequest $request */ public function save(HTTPRequest $request) { if ($this->changedData) { $this->finalize($request); if (!$this->isStarted()) { $this->start($request); } // Apply all changes recursively, implicitly writing them to the actual PHP session store. $this->recursivelyApplyChanges($this->changedData, $this->data, $_SESSION); } } /** * Recursively apply the changes represented in $data to $dest. * Used to update $_SESSION * * @deprecated 4.1.0:5.0.0 Use recursivelyApplyChanges() instead * @param array $data * @param array $dest */ protected function recursivelyApply($data, &$dest) { Deprecation::notice('5.0', 'Use recursivelyApplyChanges() instead'); foreach ($data as $k => $v) { if (is_array($v)) { if (!isset($dest[$k]) || !is_array($dest[$k])) { $dest[$k] = array(); } $this->recursivelyApply($v, $dest[$k]); } else { $dest[$k] = $v; } } } /** * Returns the list of changed keys * * @return array */ public function changedData() { return $this->changedData; } /** * Navigate to nested value in source array by name, * creating a null placeholder if it doesn't exist. * * @internal * @param string $name * @param array $source * @return mixed Reference to value in $source */ protected function &nestedValueRef($name, &$source) { // Find var to change $var = &$source; foreach (explode('.', $name) as $namePart) { if (!isset($var)) { $var = []; } if (!isset($var[$namePart])) { $var[$namePart] = null; } $var = &$var[$namePart]; } return $var; } /** * Navigate to nested value in source array by name, * returning null if it doesn't exist. * * @internal * @param string $name * @param array $source * @return mixed Value in array in $source */ protected function nestedValue($name, $source) { // Find var to change $var = $source; foreach (explode('.', $name) as $namePart) { if (!isset($var[$namePart])) { return null; } $var = $var[$namePart]; } return $var; } /** * Apply all changes using separate keys and data sources and a destination * * @internal * @param array $changes * @param array $source * @param array $destination */ protected function recursivelyApplyChanges($changes, $source, &$destination) { $source = $source ?: []; foreach ($changes as $key => $changed) { if ($changed === true) { // Determine if replacement or removal if (array_key_exists($key, $source)) { $destination[$key] = $source[$key]; } else { unset($destination[$key]); } } else { // Recursively apply $destVal = &$this->nestedValueRef($key, $destination); $sourceVal = $this->nestedValue($key, $source); $this->recursivelyApplyChanges($changed, $sourceVal, $destVal); } } } }