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, 2009 - 2012 Core Developer Team
   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 prefix to "Image"
  40                 $this->setClassPrefix('Image');
  41         }
  42
  43         /**
  44          * Creates an instance of a Image command resolver with a given default command
  45          *
  46          * @param       $commandName                            The default command we shall execute
  47          * @param       $applicationInstance            An instance of a manageable application helper class
  48          * @return      $resolverInstance                       The prepared command resolver instance
  49          * @throws      EmptyVariableException          Thrown if default command is not set
  50          * @throws      InvalidCommandException         Thrown if default command is invalid
  51          */
  52         public static final function createImageCommandResolver ($commandName, ManageableApplication $applicationInstance) {
  53                 // Create the new instance
  54                 $resolverInstance = new ImageCommandResolver();
  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($resolverInstance, 'commandName'), self::EXCEPTION_UNEXPECTED_EMPTY_STRING);
  60                 } elseif ($resolverInstance->isCommandValid($commandName) === false) {
  61                         // Invalid command found
  62                         throw new InvalidCommandException(array($resolverInstance, $commandName), self::EXCEPTION_INVALID_COMMAND);
  63                 }
  64
  65                 // Set the application instance
  66                 $resolverInstance->setApplicationInstance($applicationInstance);
  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          * it was not found
  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 resolveCommandByRequest (Requestable $requestInstance) {
  84                 // Init variables
  85                 $commandName = '';
  86                 $commandInstance = NULL;
  87
  88                 // This goes fine so let's resolve the command
  89                 $commandName = $requestInstance->getRequestElement('page');
  90
  91                 // Is the command empty? Then fall back to default command
  92                 if (empty($commandName)) {
  93                         $commandName = $this->getConfigInstance()->getConfigEntry('default_image_command');
  94                 } // END - if
  95
  96                 // Check if command is valid
  97                 if ($this->isCommandValid($commandName) === false) {
  98                         // This command is invalid!
  99                         throw new InvalidCommandException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
 100                 } // END - if
 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                 } // END - if
 110
 111                 // Set last command
 112                 $this->setResolvedInstance($commandInstance);
 113
 114                 // Return the resolved command instance
 115                 return $commandInstance;
 116         }
 117
 118         /**
 119          * Resolves the command by its direct name and returns an instance of its class
 120          *
 121          * @param       $commandName            The direct command name we shall resolve
 122          * @return      $commandInstance        An instance of the command class
 123          * @throws      InvalidCommandException         Thrown if $commandName is invalid
 124          */
 125         public function resolveCommand ($commandName) {
 126                 // Initiate the instance variable
 127                 $commandInstance = NULL;
 128
 129                 // Is the command empty? Then fall back to default command
 130                 if (empty($commandName)) {
 131                         $commandName = $this->getConfigInstance()->getConfigEntry('default_image_command');
 132                 } // END - if
 133
 134                 // Check if command is valid
 135                 if ($this->isCommandValid($commandName) === false) {
 136                         // This command is invalid!
 137                         throw new InvalidCommandException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
 138                 } // END - if
 139
 140                 // Get the command
 141                 $commandInstance = $this->loadCommand($commandName);
 142
 143                 // Return the instance
 144                 return $commandInstance;
 145         }
 146
 147         /**
 148          * "Loads" a given command and instances it if not yet cached
 149          *
 150          * @param       $commandName                            A command name we shall look for
 151          * @return      $commandInstance                        A loaded command instance
 152          * @throws      InvalidCommandException         Thrown if even the default
 153          *                                                                              command class is missing (bad!)
 154          */
 155         private function loadCommand ($commandName) {
 156                 // Init command instance
 157                 $commandInstance = NULL;
 158
 159                 // Create class name
 160                 $className = $this->getClassPrefix() . $this->convertToClassName($commandName) . 'Command';
 161
 162                 // Is this class loaded?
 163                 if (!class_exists($this->getClassName())) {
 164                         // Class not found, so throw an exception
 165                         throw new InvalidCommandException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
 166                 } // END - if
 167
 168                 // Initiate the command
 169                 $commandInstance = ObjectFactory::createObjectByName($this->getClassName(), array($this));
 170
 171                 // Return the result
 172                 return $commandInstance;
 173         }
 174 }
 175
 176 // [EOF]
 177 ?>