inc/main/classes/resolver/command/class_BaseCommandResolver.php

   1 <?php
   2 /**
   3  * A generic command resolver class
   4  *
   5  * @author              Roland Haeder <webmaster@shipsimu.org>
   6  * @version             0.0.0
   7  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2015 Core Developer Team
   8  * @license             GNU GPL 3.0 or any newer version
   9  * @link                http://www.shipsimu.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 BaseCommandResolver extends BaseResolver {
  25         /**
  26          * Protected constructor
  27          *
  28          * @param       $className      Name of the class
  29          * @return      void
  30          */
  31         protected function __construct ($className) {
  32                 // Call parent constructor
  33                 parent::__construct($className);
  34         }
  35
  36         /**
  37          * "Loads" a given command and instances it if not yet cached
  38          *
  39          * @param       $commandName                            A command name we shall look for
  40          * @return      $commandInstance                        A loaded command instance
  41          * @throws      InvalidCommandException         Thrown if even the default
  42          *                                                                              command class is missing (bad!)
  43          */
  44         protected function loadCommand ($commandName) {
  45                 // Init command instance
  46                 $commandInstance = NULL;
  47
  48                 // Create class name
  49                 $className = $this->getCapitalizedClassPrefix() . self::convertToClassName($commandName) . 'Command';
  50
  51                 // Create command class name
  52                 $this->setClassName($className);
  53
  54                 // Is this class loaded?
  55                 if (!class_exists($this->getClassName())) {
  56                         // Class not found, so throw an exception
  57                         throw new InvalidCommandException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
  58                 } // END - if
  59
  60                 // Initiate the command
  61                 $commandInstance = ObjectFactory::createObjectByName($this->getClassName(), array($this));
  62
  63                 // Return the result
  64                 return $commandInstance;
  65         }
  66
  67         /**
  68          * Returns an command instance for a given request class or null if
  69          * it was not found
  70          *
  71          * @param       $requestInstance        An instance of a request class
  72          * @return      $commandInstance        An instance of the resolved command
  73          * @throws      InvalidCommandException                         Thrown if $commandName is
  74          *                                                                                              invalid
  75          * @throws      InvalidCommandInstanceException         Thrown if $commandInstance
  76          *                                                                                              is an invalid instance
  77          */
  78         public function resolveCommandByRequest (Requestable $requestInstance) {
  79                 // Init variables
  80                 $commandName = '';
  81                 $commandInstance = NULL;
  82
  83                 // This goes fine so let's resolve the command
  84                 $commandName = $requestInstance->getRequestElement('command');
  85
  86                 // Is the command empty? Then fall back to default command
  87                 if (empty($commandName)) {
  88                         $commandName = $this->getConfigInstance()->getConfigEntry('default_' . self::getResponseTypeFromSystem() . '_command');
  89                 } // END - if
  90
  91                 // Check if command is valid
  92                 if ($this->isCommandValid($commandName) === FALSE) {
  93                         // This command is invalid!
  94                         throw new InvalidCommandException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
  95                 } // END - if
  96
  97                 // Get the command
  98                 $commandInstance = $this->loadCommand($commandName);
  99
 100                 // And validate it
 101                 if ((!is_object($commandInstance)) || (!$commandInstance instanceof Commandable)) {
 102                         // This command has an invalid instance!
 103                         throw new InvalidCommandInstanceException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
 104                 } // END - if
 105
 106                 // Set last command
 107                 $this->setResolvedInstance($commandInstance);
 108
 109                 // Return the resolved command instance
 110                 return $commandInstance;
 111         }
 112
 113         /**
 114          * Resolves the command by its direct name and returns an instance of its class
 115          *
 116          * @param       $commandName            The direct command name we shall resolve
 117          * @return      $commandInstance        An instance of the command class
 118          * @throws      InvalidCommandException         Thrown if $commandName is invalid
 119          */
 120         public function resolveCommand ($commandName) {
 121                 // Initiate the instance variable
 122                 $commandInstance = NULL;
 123
 124                 // Is the command empty? Then fall back to default command
 125                 if (empty($commandName)) {
 126                         $commandName = $this->getConfigInstance()->getConfigEntry('default_' . self::getResponseTypeFromSystem() . '_command');
 127                 } // END - if
 128
 129                 // Check if command is valid
 130                 if ($this->isCommandValid($commandName) === FALSE) {
 131                         // This command is invalid!
 132                         throw new InvalidCommandException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
 133                 } // END - if
 134
 135                 // Get the command
 136                 $commandInstance = $this->loadCommand($commandName);
 137
 138                 // Return the instance
 139                 return $commandInstance;
 140         }
 141
 142         /**
 143          * Checks whether the given command is valid
 144          *
 145          * @param       $commandName    The default command we shall execute
 146          * @return      $isValid                Whether the given command is valid
 147          * @throws      EmptyVariableException  Thrown if given command is not set
 148          */
 149         public function isCommandValid ($commandName) {
 150                 // By default nothing shall be valid
 151                 $isValid = FALSE;
 152
 153                 // Is a command set?
 154                 if (empty($commandName)) {
 155                         // Then thrown an exception here
 156                         throw new EmptyVariableException(array($this, 'commandName'), self::EXCEPTION_UNEXPECTED_EMPTY_STRING);
 157                 } // END - if
 158
 159                 // Create the full class name
 160                 $className = $this->getCapitalizedClassPrefix() . self::convertToClassName($commandName) . 'Command';
 161
 162                 // Now, let us create the full name of the command class
 163                 $this->setClassName($className);
 164
 165                 // Is this class already loaded?
 166                 if (class_exists($this->getClassName())) {
 167                         // This class does exist. :-)
 168                         $isValid = TRUE;
 169                 } // END - if
 170
 171                 // Set command name
 172                 $this->setCommandName($commandName);
 173
 174                 // Return the result
 175                 return $isValid;
 176         }
 177 }
 178
 179 // [EOF]
 180 ?>