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Diffstat (limited to 'lib/trails/Dispatcher.php')
| -rw-r--r-- | lib/trails/Dispatcher.php | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/lib/trails/Dispatcher.php b/lib/trails/Dispatcher.php new file mode 100644 index 0000000..efa90c7 --- /dev/null +++ b/lib/trails/Dispatcher.php @@ -0,0 +1,262 @@ +<?php +namespace Trails; + +use Trails\Exceptions\MissingFile; +use Trails\Exceptions\RoutingError; +use Trails\Exceptions\UnknownController; + +/** + * The Dispatcher is used to map an incoming HTTP request to a Controller + * producing a response which is then rendered. To initialize an instance of + * class Dispatcher you have to give three configuration settings: + * + * trails_root - the absolute file path to a directory containing the + * applications controllers, views etc. + * trails_uri - the URI to which routes to mapped Controller/Actions + * are appended + * default_controller - the route to a controller, that is used if no + * controller is given, that is the route is equal to '/' + * + * After instantiation of a dispatcher you have to call method #dispatch with + * the request uri to be mapped to a controller/action pair. + * + * @package trails + * + * @author mlunzena + * @copyright (c) Authors + * @version $Id: trails.php 7001 2008-04-04 11:20:27Z mlunzena $ + */ +class Dispatcher +{ + # TODO (mlunzena) Konfiguration muss anders geschehen + + /** + * This is the absolute file path to the trails application directory. + */ + public string $trails_root; + + /** + * This is the URI to which routes to controller/actions are appended. + */ + public string $trails_uri; + + /** + * This variable contains the route to the default controller. + */ + public string $default_controller; + + /** + * @param string $trails_root absolute file path to a directory containing the + * applications controllers, views etc. + * @param string $trails_uri the URI to which routes to mapped Controller/Actions + * are appended + * @param string $default_controller the route to a controller, that is used if no + * controller is given, that is the route is equal to '/' + */ + public function __construct( + string $trails_root, + string $trails_uri, + string $default_controller + ) { + $this->trails_root = $trails_root; + $this->trails_uri = $trails_uri; + $this->default_controller = $default_controller; + } + + /** + * Maps a string to a response which is then rendered. + * + * @param string $uri The requested URI. + */ + public function dispatch($uri) + { + # E_USER_ERROR|E_USER_WARNING|E_USER_NOTICE|E_RECOVERABLE_ERROR = 5888 + $old_handler = set_error_handler([$this, 'error_handler'], 5888); + + ob_start(); + $level = ob_get_level(); + + $this->map_uri_to_response($this->clean_request_uri((string) $uri))->output(); + + while (ob_get_level() >= $level) { + ob_end_flush(); + } + + if (isset($old_handler)) { + set_error_handler($old_handler); + } + } + + /** + * Maps an URI to a response by figuring out first what controller to + * instantiate, then delegating the unconsumed part of the URI to the + * controller who returns an appropriate response object or throws an + * Exception. + * + * @param string $uri the URI string + * @return Response a response object + */ + public function map_uri_to_response($uri) + { + try { + [$controller_path, $unconsumed] = '' === $uri ? $this->default_route() : $this->parse($uri); + + $controller = $this->load_controller($controller_path); + + $response = $controller->perform($unconsumed); + } catch (Exception $e) { + $response = isset($controller) ? $controller->rescue($e) : $this->trails_error($e); + } + + return $response; + } + + /** + * @return array an array containing the default controller and an + * empty unconsumed route + * @throws MissingFile + */ + public function default_route() + { + if (!$this->file_exists($this->default_controller . '.php')) { + throw new Exceptions\MissingFile( + "Default controller '{$this->default_controller}' not found'" + ); + } + return [$this->default_controller, '']; + } + + public function trails_error($exception) + { + ob_clean(); + + # show details for local requests + $detailed = @$_SERVER['REMOTE_ADDR'] === '127.0.0.1'; + + $body = sprintf('<html><head><title>Trails Error</title></head>' . + '<body><h1>%s</h1><pre>%s</pre></body></html>', + htmlentities($exception->__toString()), + $detailed + ? htmlentities($exception->getTraceAsString()) + : ''); + + if ($exception instanceof Exception) { + $response = new Response( + $body, + $exception->getHeaders(), + $exception->getCode(), + $exception->getMessage() + ); + } else { + $response = new Response( + $body, + [], + 500, + $exception->getMessage() + ); + } + + return $response; + } + + /** + * Clean up URI string by removing the query part and leading slashes. + * + * @param string $uri an URI string + * @return string the cleaned string + */ + public function clean_request_uri($uri) + { + $pos = strpos($uri, '?'); + if ($pos !== false) { + $uri = substr($uri, 0, $pos); + } + return ltrim($uri, '/'); + } + + /** + * @param string $unconsumed + * @param string $controller + * @return array + * @throws RoutingError + */ + public function parse($unconsumed, $controller = null) + { + [$head, $tail] = $this->split_on_first_slash($unconsumed); + + if (!preg_match('/^\w+$/', $head)) { + throw new RoutingError("No route matches '$head'"); + } + + $controller = (isset($controller) ? $controller . '/' : '') . $head; + + if ($this->file_exists($controller . '.php')) { + return [$controller, $tail]; + } + + if ($this->file_exists($controller)) { + return $this->parse($tail, $controller); + } + + throw new RoutingError("No route matches '$head'"); + } + + /** + * @param string $str + * @return array + */ + public function split_on_first_slash($str) + { + preg_match(":([^/]*)(/+)?(.*):", $str, $matches); + return [$matches[1], $matches[3]]; + } + + /** + * @param string $path + * @return bool + */ + public function file_exists($path) + { + return file_exists("{$this->trails_root}/controllers/$path"); + } + + /** + * Loads the controller file for a given controller path and return an + * instance of that controller. If an error occures, an exception will be + * thrown. + * + * @param string $controller the relative controller path + * @return Controller an instance of that controller + * @throws UnknownController + */ + public function load_controller($controller) + { + require_once "{$this->trails_root}/controllers/{$controller}.php"; + $class = Inflector::camelize($controller) . 'Controller'; + if (!class_exists($class)) { + throw new UnknownController("Controller missing: '$class'"); + } + return new $class($this); + } + + /** + * This method transforms E_USER_* and E_RECOVERABLE_ERROR to + * Exceptions. + * + * @param integer $errno the level of the error raised + * @param string $string the error message + * @param string $file the filename that the error was raised in + * @param integer $line the line number the error was raised at + * + * @return bool + * @throws Exception + * + */ + public function error_handler($errno, $string, $file, $line) + { + if (!(5888 & $errno)) { + return false; + } + throw new Exception(500, $string); + } +} |