http/front_controller.php

   1 <?php
   2 // Hoplite
   3 // Copyright (c) 2015 Blue Static
   4 //
   5 // This program is free software: you can redistribute it and/or modify it
   6 // under the terms of the GNU General Public License as published by the Free
   7 // Software Foundation, either version 3 of the License, or any later version.
   8 //
   9 // This program is distributed in the hope that it will be useful, but WITHOUT
  10 // ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11 // FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12 // more details.
  13 //
  14 // You should have received a copy of the GNU General Public License along with
  15 // this program.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 namespace hoplite\http;
  18
  19 require_once HOPLITE_ROOT . '/http/interceptor.php';
  20 require_once HOPLITE_ROOT . '/http/request.php';
  21 require_once HOPLITE_ROOT . '/http/response.php';
  22 require_once HOPLITE_ROOT . '/http/response_code.php';
  23
  24 /*!
  25   The FrontController is meant to be invoked from the index.php of the
  26   application.
  27 */
  28 class FrontController
  29 {
  30   /*! @var Request */
  31   private $request = NULL;
  32
  33   /*! @var Response */
  34   private $response = NULL;
  35
  36   /*! @var UrlMap */
  37   private $url_map = NULL;
  38
  39   /*! @var OutputFilter */
  40   private $output_filter = NULL;
  41
  42   /*! @var Array<Interceptor> */
  43   private $interceptors = [];
  44
  45   /*!
  46     Creates the controller with the request context information, typicallhy
  47     from the global scope ($GLOBALS), but can be injected for testing.
  48     @param array PHP globals array
  49   */
  50   public function __construct(array $globals)
  51   {
  52     $this->response = new Response();
  53     $this->request = new Request();
  54     $this->request->data = array(
  55       '_GET'    => &$globals['_GET'],
  56       '_POST'   => &$globals['_POST'],
  57       '_COOKIE' => &$globals['_COOKIE'],
  58       '_SERVER' => &$globals['_SERVER']
  59     );
  60   }
  61
  62   /*! Accessors */
  63   public function request() { return $this->request; }
  64   public function response() { return $this->response; }
  65
  66   /*! Sets the UrlMap. */
  67   public function set_url_map(UrlMap $url_map) { $this->url_map = $url_map; }
  68
  69   /*! Sest the Output Filter. */
  70   public function set_output_filter(OutputFilter $output_filter)
  71   {
  72     $this->output_filter = $output_filter;
  73   }
  74
  75   /*! Registers an Interceptor that will be run before executing an Action. */
  76   public function AddInterceptor(Interceptor $interceptor)
  77   {
  78     $this->interceptors[] = $interceptor;
  79   }
  80
  81   /*!
  82     Called in index.php to process the current HTTP request. This initializes the
  83     Request object from its data and then routes the request to generate the
  84     response.
  85    */
  86   public function ProcessRequest()
  87   {
  88     // The query rewriter module of the webserver rewrites a request from:
  89     //    http://example.com/webapp/user/view/42
  90     // to:
  91     //    http://example.com/webapp/index.php/user/view/42
  92     // ... which then becomes accessible from PATH_INFO.
  93     $data = $this->request->data['_SERVER'];
  94     if (isset($data['PATH_INFO']))
  95       $url = $data['PATH_INFO'];
  96     else
  97       $url = str_replace($_SERVER['SCRIPT_NAME'], '', $_SERVER['DOCUMENT_URI']);
  98
  99     $this->request->data['HOPLITE_PATH_INFO'] = $url;
 100
 101     if ($url[0] == '/')
 102       $url = substr($url, 1);
 103
 104     // Set the final pieces of the request.
 105     $this->request->url = $url;
 106     $this->request->http_method = $this->request->data['_SERVER']['REQUEST_METHOD'];
 107
 108     // Extract any PUT data as POST params.
 109     if ($this->request->http_method == 'PUT')
 110       parse_str(file_get_contents('php://input'), $this->request->data['_POST']);
 111
 112     // Register self as the active instance.
 113     $GLOBALS[__CLASS__] = $this;
 114
 115     // Dispatch the request to an Action.
 116     $this->RouteRequest($this->request);
 117
 118     // When control returns here, all actions have been invoked and it's time
 119     // to start the output filter and exit.
 120     $this->SendResponse();
 121   }
 122
 123   /*!
 124     Prevents any other Actions from executing. This starts the OutputFilter and
 125     then exits.
 126   */
 127   public function SendResponse()
 128   {
 129     $this->output_filter->FilterOutput($this->request, $this->response);
 130     $this->_Exit();
 131   }
 132
 133   /*!
 134     Sets the response code and stops the controller. Returns void.
 135   */
 136   public function SendResponseCode($code)
 137   {
 138     $this->response->response_code = $code;
 139     $this->SendResponse();
 140   }
 141
 142   /*!
 143     Sets the response code to HTTP 302 FOUND and redirects the page to a new
 144     location.
 145     @param string The destination location of the redirect.
 146   */
 147   public function SendResponseRedirect($location)
 148   {
 149     $this->response->headers['Location'] = $location;
 150     $this->SendResponseCode(ResponseCode::FOUND);
 151   }
 152
 153   /*!
 154     Wrapper around PHP exit().
 155   */
 156   protected function _Exit()
 157   {
 158     exit;
 159   }
 160
 161   /*!
 162     Given an Request object, this executes the action for the corresponding URL.
 163     The action is located by performing a lookup in the UrlMap. Interceptors
 164     are run before invoking the action.
 165     @param Request The Request whose URL will be routed
 166   */
 167   public function RouteRequest(Request $request)
 168   {
 169     $url_map_value = $this->url_map->Evaluate($request);
 170
 171     $action = NULL;
 172     if ($url_map_value)
 173       $action = $this->url_map->LookupAction($url_map_value);
 174
 175     foreach ($this->interceptors as $interceptor)
 176       $interceptor->DoIntercept($this, $action, $request, $this->response);
 177
 178     if ($action)
 179       $this->InvokeAction($action);
 180   }
 181
 182   /*!
 183     Invokes the action with the Controller's request and response objects.
 184    */
 185   public function InvokeAction(Action $action)
 186   {
 187     $action->Invoke($this->request, $this->response);
 188   }
 189
 190   /*!
 191     Performs a reverse-lookup in the UrlMap for the pattern/fragment for the
 192     name of a given Action class.
 193     @param string Class name.
 194   */
 195   public function LookupAction($class)
 196   {
 197     $map = $this->url_map->map();
 198     foreach ($map as $pattern => $action) {
 199       if ($action == $class)
 200         return $pattern;
 201     }
 202   }
 203
 204   /*!
 205     Given a relative path, return an absolute path from the root controller.
 206     @param string The relative path for which a URL will be created
 207     @param bool Include the HTTP scheme and host to create an RFC URL if true;
 208                 if false an absolute path will be returned.
 209   */
 210   public function MakeURL($new_path, $url = FALSE)
 211   {
 212     // Detect the common paths between the REQUEST_URI and the PATH_INFO. That
 213     // common piece will be the path to the root controller.
 214     $request_uri = $this->request()->data['_SERVER']['REQUEST_URI'];
 215     $path_info = $this->request()->data['HOPLITE_PATH_INFO'];
 216     if (!$path_info)
 217       $common_uri = substr($request_uri, 0, -1);
 218     else
 219       $common_uri = strstr($request_uri, $path_info, TRUE);
 220
 221     // If just constructing an absolute path, return that now.
 222     if (!$url)
 223       return $common_uri . $new_path;
 224
 225     // Otherwise, build the host part.
 226     $url = 'http';
 227     if (isset($this->request()->data['_SERVER']['HTTPS']) &&
 228         $this->request()->data['_SERVER']['HTTPS'] == 'on') {
 229       $url .= 's';
 230     }
 231     $url .= '://' . $this->request()->data['_SERVER']['HTTP_HOST'];
 232
 233     $port = $this->request()->data['_SERVER']['SERVER_PORT'];
 234     if ($port != 80 && $port != 443)
 235       $url .= ':' . $port;
 236
 237     $url .= $common_uri;
 238     return $url . $new_path;
 239   }
 240 }