inc/classes/main/resolver/command/image/class_ImageCommandResolver.php

   1 <?php
   2 /**
   3  * A command resolver for local (non-hubbed) image 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 ImageCommandResolver extends BaseCommandResolver implements CommandResolver {
  25         /**
  26          * Last successfull resolved command
  27          */
  28         private $lastCommandInstance = null;
  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 part description
  40                 $this->setObjectDescription("Resolver for local image commands");
  41
  42                 // Create unique ID number
  43                 $this->generateUniqueId();
  44
  45                 // Set prefix to "Image"
  46                 $this->setCommandPrefix("Image");
  47         }
  48
  49         /**
  50          * Creates an instance of a Image command resolver with a given default command
  51          *
  52          * @param       $commandName                            The default command we shall execute
  53          * @param       $appInstance                            An instance of a manageable application helper class
  54          * @return      $resolverInstance                       The prepared command resolver instance
  55          * @throws      EmptyVariableException          Thrown if the default command is not set
  56          * @throws      InvalidCommandException         Thrown if the default command is invalid
  57          */
  58         public final static function createImageCommandResolver ($commandName, ManageableApplication $appInstance) {
  59                 // Create the new instance
  60                 $resolverInstance = new ImageCommandResolver();
  61
  62                 // Is the variable $commandName set and the command is valid?
  63                 if (empty($commandName)) {
  64                         // Then thrown an exception here
  65                         throw new EmptyVariableException(array($resolverInstance, 'commandName'), self::EXCEPTION_UNEXPECTED_EMPTY_STRING);
  66                 } elseif (!$resolverInstance->isCommandValid($commandName)) {
  67                         // Invalid command found
  68                         throw new InvalidCommandException(array($resolverInstance, $commandName), self::EXCEPTION_INVALID_COMMAND);
  69                 }
  70
  71                 // Set the application instance
  72                 $resolverInstance->setApplicationInstance($appInstance);
  73
  74                 // Return the prepared instance
  75                 return $resolverInstance;
  76         }
  77
  78         /**
  79          * Returns an command instance for a given request class or null if
  80          * it was not found
  81          *
  82          * @param       $requestInstance        An instance of a request class
  83          * @return      $commandInstance        An instance of the resolved command
  84          * @throws      InvalidCommandException                         Thrown if $commandName is
  85          *                                                                                              invalid
  86          * @throws      InvalidCommandInstanceException         Thrown if $commandInstance
  87          *                                                                                              is an invalid instance
  88          */
  89         public function resolveCommandByRequest (Requestable $requestInstance) {
  90                 // Init variables
  91                 $commandName = "";
  92                 $commandInstance = null;
  93
  94                 // This goes fine so let's resolv the command
  95                 $commandName = $requestInstance->getRequestElement('page');
  96
  97                 // Is the command empty? Then fall back to default command
  98                 if (empty($commandName)) $commandName = $this->getConfigInstance()->readConfig('default_image_command');
  99
 100                 // Check if the command is valid
 101                 if (!$this->isCommandValid($commandName)) {
 102                         // This command is invalid!
 103                         throw new InvalidCommandException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
 104                 } // END - if
 105
 106                 // Get the command
 107                 $commandInstance = $this->loadCommand($commandName);
 108
 109                 // And validate it
 110                 if ((!is_object($commandInstance)) || (!$commandInstance instanceof Commandable)) {
 111                         // This command has an invalid instance!
 112                         throw new InvalidCommandInstanceException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
 113                 } // END - if
 114
 115                 // Set last command
 116                 $this->lastCommandInstance = $commandInstance;
 117
 118                 // Return the resolved command instance
 119                 return $commandInstance;
 120         }
 121
 122         /**
 123          * Resolves the command by its direct name and returns an instance of its class
 124          *
 125          * @param       $commandName            The direct command name we shall resolve
 126          * @return      $commandInstance        An instance of the command class
 127          * @throws      InvalidCommandException         Thrown if $commandName is invalid
 128          */
 129         public function resolveCommand ($commandName) {
 130                 // Initiate the instance variable
 131                 $commandInstance = null;
 132
 133                 // Is the command empty? Then fall back to default command
 134                 if (empty($commandName)) $commandName = $this->getConfigInstance()->readConfig('default_image_command');
 135
 136                 // Check if the command is valid
 137                 if (!$this->isCommandValid($commandName)) {
 138                         // This command is invalid!
 139                         throw new InvalidCommandException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
 140                 }
 141
 142                 // Get the command
 143                 $commandInstance = $this->loadCommand($commandName);
 144
 145                 // Return the instance
 146                 return $commandInstance;
 147         }
 148
 149         /**
 150          * "Loads" a given command and instances it if not yet cached
 151          *
 152          * @param       $commandName                            A command name we shall look for
 153          * @return      $commandInstance                        A loaded command instance
 154          * @throws      InvalidCommandException         Thrown if even the default
 155          *                                                                              command class is missing (bad!)
 156          */
 157         private function loadCommand ($commandName) {
 158                 // Cache default command
 159                 $defaultCommand = $this->getConfigInstance()->readConfig('default_image_command');
 160
 161                 // Init command instance
 162                 $commandInstance = null;
 163
 164                 // Create command class name
 165                 $this->setClassName(sprintf("Image%sCommand",
 166                         $this->convertToClassName($commandName)
 167                 ));
 168
 169                 // Is this class loaded?
 170                 if (!class_exists($this->getClassName())) {
 171                         // Class not found, so throw an exception
 172                         throw new InvalidCommandException(array($this, $defaultCommand), self::EXCEPTION_INVALID_COMMAND);
 173                 } // END - if
 174
 175                 // Initiate the command
 176                 $commandInstance = ObjectFactory::createObjectByName($this->getClassName(), array($this));
 177
 178                 // Return the result
 179                 return $commandInstance;
 180         }
 181 }
 182
 183 // [EOF]
 184 ?>