inc/classes/main/resolver/web/class_WebCommandResolver.php

   1 <?php
   2 /**
   3  * A command resolver for local (non-hubbed) commands
   4  *
   5  * @author              Roland Haeder <webmaster@ship-simu.org>
   6  * @version             0.0.0
   7  * @copyright   Copyright(c) 2007, 2008 Roland Haeder, this is free software
   8  * @license             GNU GPL 3.0 or any newer version
   9  * @link                http://www.ship-simu.org
  10  *
  11  * This program is free software: you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation, either version 3 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  23  */
  24 class WebCommandResolver extends BaseResolver implements CommandResolver {
  25         /**
  26          * Last successfull resolved command
  27          */
  28         private $lastCommandInstance = "";
  29
  30         /**
  31          * Protected constructor
  32          *
  33          * @return      void
  34          */
  35         protected function __construct () {
  36                 // Call parent constructor
  37                 parent::__construct(__CLASS__);
  38
  39                 // Set prefix to "Web"
  40                 $this->setCommandPrefix("Web");
  41         }
  42
  43         /**
  44          * Creates an instance of a Web command resolver with a given default command
  45          *
  46          * @param       $commandName                            The default command we shall execute
  47          * @param       $appInstance                            An instance of a manageable application helper class
  48          * @return      $resolverInstance                       The prepared command resolver instance
  49          * @throws      EmptyVariableException          Thrown if the default command is not set
  50          * @throws      InvalidCommandException         Thrown if the default command is invalid
  51          */
  52         public final static function createWebCommandResolver ($commandName, ManageableApplication $appInstance) {
  53                 // Create the new instance
  54                 $resolverInstance = new WebCommandResolver();
  55
  56                 // Is the variable $commandName set and the command is valid?
  57                 if (empty($commandName)) {
  58                         // Then thrown an exception here
  59                         throw new EmptyVariableException(array($resolverInstance, 'defaultCommand'), self::EXCEPTION_UNEXPECTED_EMPTY_STRING);
  60                 } elseif (!$resolverInstance->isCommandValid($commandName)) {
  61                         // Invalid command found
  62                         throw new InvalidCommandException(array($resolverInstance, $commandName), self::EXCEPTION_INVALID_COMMAND);
  63                 }
  64
  65                 // Set the application instance
  66                 $resolverInstance->setApplicationInstance($appInstance);
  67
  68                 // Return the prepared instance
  69                 return $resolverInstance;
  70         }
  71
  72         /**
  73          * Returns an command instance for a given request class or null if
  74          * MissingArrayElementsException was thrown
  75          *
  76          * @param       $requestInstance        An instance of a request class
  77          * @return      $commandInstance        An instance of the resolved command
  78          * @throws      InvalidCommandException                         Thrown if $commandName is
  79          *                                                                                              invalid
  80          * @throws      InvalidCommandInstanceException         Thrown if $commandInstance
  81          *                                                                                              is an invalid instance
  82          */
  83         public function resolvCommandByRequest (Requestable $requestInstance) {
  84                 // Init variables
  85                 $commandName = "";
  86                 $commandInstance = null;
  87
  88                 // Test if the required parameter is set
  89                 try {
  90                         // This goes fine so let's resolv the command
  91                         $commandName = $requestInstance->getRequestElement("page");
  92
  93                         // Is the command empty? Then fall back to default command
  94                         if (empty($commandName)) $commandName = $this->getConfigInstance()->readConfig('default_command');
  95
  96                         // Check if the command is valid
  97                         if (!$this->isCommandValid($commandName)) {
  98                                 // This command is invalid!
  99                                 throw new InvalidCommandException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
 100                         }
 101
 102                         // Get the command
 103                         $commandInstance = $this->loadCommand($commandName);
 104
 105                         // And validate it
 106                         if ((!is_object($commandInstance)) || (!$commandInstance instanceof Commandable)) {
 107                                 // This command has an invalid instance!
 108                                 throw new InvalidCommandInstanceException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
 109                         }
 110
 111                         // Set last command
 112                         $this->lastCommandInstance = $commandInstance;
 113                 } catch (MissingArrayElementsException $e) {
 114                         // Just catch it here...
 115                 }
 116
 117                 // Return the resolved command instance
 118                 return $commandInstance;
 119         }
 120
 121         /**
 122          * Resolves the command by its direct name and returns an instance of its class
 123          *
 124          * @param       $commandName            The direct command name we shall resolve
 125          * @return      $commandInstance        An instance of the command class
 126          * @throws      InvalidCommandException         Thrown if $commandName is invalid
 127          */
 128         public function resolveCommand ($commandName) {
 129                 // Initiate the instance variable
 130                 $commandInstance = null;
 131
 132                 // Is the command empty? Then fall back to default command
 133                 if (empty($commandName)) $commandName = $this->getConfigInstance()->readConfig('default_command');
 134
 135                 // Check if the command is valid
 136                 if (!$this->isCommandValid($commandName)) {
 137                         // This command is invalid!
 138                         throw new InvalidCommandException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
 139                 }
 140
 141                 // Get the command
 142                 $commandInstance = $this->loadCommand($commandName);
 143
 144                 // Return the instance
 145                 return $commandInstance;
 146         }
 147
 148         /**
 149          * "Loads" a given command and instances it if not yet cached
 150          *
 151          * @param       $commandName                            A command name we shall look for
 152          * @return      $commandInstance                        A loaded command instance
 153          * @throws      InvalidCommandException         Thrown if even the default
 154          *                                                                              command class is missing (bad!)
 155          */
 156         private function loadCommand ($commandName) {
 157                 // Cache default command
 158                 $defaultCommand = $this->getConfigInstance()->readConfig('default_command');
 159
 160                 // Init command instance
 161                 $commandInstance = null;
 162
 163                 // Create command class name
 164                 $className = sprintf("Web%sCommand",
 165                         $this->convertToClassName($commandName)
 166                 );
 167
 168                 // Is this class loaded?
 169                 if (!class_exists($className)) {
 170                         // Class not found, so try the default one or throw exception
 171                         if ($commandName != $defaultCommand) {
 172                                 // Try the default command
 173                                 return $this->loadCommand($defaultCommand);
 174                         } else {
 175                                 // Still not found?
 176                                 throw new InvalidCommandException(array($this, $defaultCommand), self::EXCEPTION_INVALID_COMMAND);
 177                         }
 178                 } // END - if
 179
 180                 // Initiate the command
 181                 $commandInstance = ObjectFactory::createObjectByName($className, array($this));
 182
 183                 // Return the result
 184                 return $commandInstance;
 185         }
 186 }
 187
 188 // [EOF]
 189 ?>