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       $url = '/';
  98     if ($url[0] == '/')
  99       $url = substr($url, 1);
 100
 101     // Set the final pieces of the request.
 102     $this->request->url = $url;
 103     $this->request->http_method = $this->request->data['_SERVER']['REQUEST_METHOD'];
 104
 105     // Extract any PUT data as POST params.
 106     if ($this->request->http_method == 'PUT')
 107       parse_str(file_get_contents('php://input'), $this->request->data['_POST']);
 108
 109     // Register self as the active instance.
 110     $GLOBALS[__CLASS__] = $this;
 111
 112     // Dispatch the request to an Action.
 113     $this->RouteRequest($this->request);
 114
 115     // When control returns here, all actions have been invoked and it's time
 116     // to start the output filter and exit.
 117     $this->SendResponse();
 118   }
 119
 120   /*!
 121     Prevents any other Actions from executing. This starts the OutputFilter and
 122     then exits.
 123   */
 124   public function SendResponse()
 125   {
 126     $this->output_filter->FilterOutput($this->request, $this->response);
 127     $this->_Exit();
 128   }
 129
 130   /*!
 131     Sets the response code and stops the controller. Returns void.
 132   */
 133   public function SendResponseCode($code)
 134   {
 135     $this->response->response_code = $code;
 136     $this->SendResponse();
 137   }
 138
 139   /*!
 140     Sets the response code to HTTP 302 FOUND and redirects the page to a new
 141     location.
 142     @param string The destination location of the redirect.
 143   */
 144   public function SendResponseRedirect($location)
 145   {
 146     $this->response->headers['Location'] = $location;
 147     $this->SendResponseCode(ResponseCode::FOUND);
 148   }
 149
 150   /*!
 151     Wrapper around PHP exit().
 152   */
 153   protected function _Exit()
 154   {
 155     exit;
 156   }
 157
 158   /*!
 159     Given an Request object, this executes the action for the corresponding URL.
 160     The action is located by performing a lookup in the UrlMap. Interceptors
 161     are run before invoking the action.
 162     @param Request The Request whose URL will be routed
 163   */
 164   public function RouteRequest(Request $request)
 165   {
 166     $url_map_value = $this->url_map->Evaluate($request);
 167
 168     $action = NULL;
 169     if ($url_map_value)
 170       $action = $this->url_map->LookupAction($url_map_value);
 171
 172     foreach ($this->interceptors as $interceptor)
 173       $interceptor->DoIntercept($this, $action, $request, $this->response);
 174
 175     if ($action)
 176       $action->Invoke($request, $this->response);
 177   }
 178
 179   /*!
 180     Performs a reverse-lookup in the UrlMap for the pattern/fragment for the
 181     name of a given Action class.
 182     @param string Class name.
 183   */
 184   public function LookupAction($class)
 185   {
 186     $map = $this->url_map->map();
 187     foreach ($map as $pattern => $action) {
 188       if ($action == $class)
 189         return $pattern;
 190     }
 191   }
 192
 193   /*!
 194     Given a relative path, return an absolute path from the root controller.
 195     @param string The relative path for which a URL will be created
 196     @param bool Include the HTTP scheme and host to create an RFC URL if true;
 197                 if false an absolute path will be returned.
 198   */
 199   public function MakeURL($new_path, $url = FALSE)
 200   {
 201     // Detect the common paths between the REQUEST_URI and the PATH_INFO. That
 202     // common piece will be the path to the root controller.
 203     $request_uri = $this->request()->data['_SERVER']['REQUEST_URI'];
 204     $path_info = $this->request()->data['_SERVER']['PATH_INFO'];
 205     if ($path_info === NULL)
 206       $common_uri = substr($request_uri, 0, -1);
 207     else
 208       $common_uri = strstr($request_uri, $path_info, TRUE);
 209
 210     // If just constructing an absolute path, return that now.
 211     if (!$url)
 212       return $common_uri . $new_path;
 213
 214     // Otherwise, build the host part.
 215     $url = 'http';
 216     if (isset($this->request()->data['_SERVER']['HTTPS']) &&
 217         $this->request()->data['_SERVER']['HTTPS'] == 'on') {
 218       $url .= 's';
 219     }
 220     $url .= '://' . $this->request()->data['_SERVER']['HTTP_HOST'];
 221
 222     $port = $this->request()->data['_SERVER']['SERVER_PORT'];
 223     if ($port != 80 && $port != 443)
 224       $url .= ':' . $port;
 225
 226     $url .= $common_uri;
 227     return $url . $new_path;
 228   }
 229 }