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

   1 <?php
   2 // Own namespace
   3 namespace CoreFramework\Resolver\Controller;
   4
   5 /**
   6  * A generic command resolver class
   7  *
   8  * @author              Roland Haeder <webmaster@shipsimu.org>
   9  * @version             0.0.0
  10  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2017 Core Developer Team
  11  * @license             GNU GPL 3.0 or any newer version
  12  * @link                http://www.shipsimu.org
  13  *
  14  * This program is free software: you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation, either version 3 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * This program is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  26  */
  27 class BaseCommandResolver extends BaseResolver {
  28         /**
  29          * Protected constructor
  30          *
  31          * @param       $className      Name of the class
  32          * @return      void
  33          */
  34         protected function __construct ($className) {
  35                 // Call parent constructor
  36                 parent::__construct($className);
  37         }
  38
  39         /**
  40          * "Loads" a given command and instances it if not yet cached
  41          *
  42          * @param       $commandName                            A command name we shall look for
  43          * @return      $commandInstance                        A loaded command instance
  44          * @throws      InvalidCommandException         Thrown if even the default
  45          *                                                                              command class is missing (bad!)
  46          */
  47         protected function loadCommand ($commandName) {
  48                 // Init command instance
  49                 $commandInstance = NULL;
  50
  51                 // Create class name
  52                 $className = $this->getCapitalizedClassPrefix() . self::convertToClassName($commandName) . 'Command';
  53
  54                 // Create command class name
  55                 $this->setClassName($className);
  56
  57                 // Is this class loaded?
  58                 if (!class_exists($this->getClassName())) {
  59                         // Class not found, so throw an exception
  60                         throw new InvalidCommandException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
  61                 } // END - if
  62
  63                 // Initiate the command
  64                 $commandInstance = ObjectFactory::createObjectByName($this->getClassName(), array($this));
  65
  66                 // Return the result
  67                 return $commandInstance;
  68         }
  69
  70         /**
  71          * Returns an command instance for a given request class or null if
  72          * it was not found
  73          *
  74          * @param       $requestInstance        An instance of a request class
  75          * @return      $commandInstance        An instance of the resolved command
  76          * @throws      InvalidCommandException                         Thrown if $commandName is
  77          *                                                                                              invalid
  78          * @throws      InvalidCommandInstanceException         Thrown if $commandInstance
  79          *                                                                                              is an invalid instance
  80          */
  81         public function resolveCommandByRequest (Requestable $requestInstance) {
  82                 // Init variables
  83                 $commandName = '';
  84                 $commandInstance = NULL;
  85
  86                 // This goes fine so let's resolve the command
  87                 $commandName = $requestInstance->getRequestElement('command');
  88
  89                 // Is the command empty? Then fall back to default command
  90                 if (empty($commandName)) {
  91                         $commandName = $this->getConfigInstance()->getConfigEntry('default_' . self::getResponseTypeFromSystem() . '_command');
  92                 } // END - if
  93
  94                 // Check if command is valid
  95                 if ($this->isCommandValid($commandName) === FALSE) {
  96                         // This command is invalid!
  97                         throw new InvalidCommandException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
  98                 } // END - if
  99
 100                 // Get the command
 101                 $commandInstance = $this->loadCommand($commandName);
 102
 103                 // And validate it
 104                 if ((!is_object($commandInstance)) || (!$commandInstance instanceof Commandable)) {
 105                         // This command has an invalid instance!
 106                         throw new InvalidCommandInstanceException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
 107                 } // END - if
 108
 109                 // Set last command
 110                 $this->setResolvedInstance($commandInstance);
 111
 112                 // Return the resolved command instance
 113                 return $commandInstance;
 114         }
 115
 116         /**
 117          * Resolves the command by its direct name and returns an instance of its class
 118          *
 119          * @param       $commandName            The direct command name we shall resolve
 120          * @return      $commandInstance        An instance of the command class
 121          * @throws      InvalidCommandException         Thrown if $commandName is invalid
 122          */
 123         public function resolveCommand ($commandName) {
 124                 // Initiate the instance variable
 125                 $commandInstance = NULL;
 126
 127                 // Is the command empty? Then fall back to default command
 128                 if (empty($commandName)) {
 129                         $commandName = $this->getConfigInstance()->getConfigEntry('default_' . self::getResponseTypeFromSystem() . '_command');
 130                 } // END - if
 131
 132                 // Check if command is valid
 133                 if ($this->isCommandValid($commandName) === FALSE) {
 134                         // This command is invalid!
 135                         throw new InvalidCommandException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
 136                 } // END - if
 137
 138                 // Get the command
 139                 $commandInstance = $this->loadCommand($commandName);
 140
 141                 // Return the instance
 142                 return $commandInstance;
 143         }
 144
 145         /**
 146          * Checks whether the given command is valid
 147          *
 148          * @param       $commandName    The default command we shall execute
 149          * @return      $isValid                Whether the given command is valid
 150          * @throws      EmptyVariableException  Thrown if given command is not set
 151          */
 152         public function isCommandValid ($commandName) {
 153                 // By default nothing shall be valid
 154                 $isValid = FALSE;
 155
 156                 // Is a command set?
 157                 if (empty($commandName)) {
 158                         // Then thrown an exception here
 159                         throw new EmptyVariableException(array($this, 'commandName'), self::EXCEPTION_UNEXPECTED_EMPTY_STRING);
 160                 } // END - if
 161
 162                 // Create the full class name
 163                 $className = $this->getCapitalizedClassPrefix() . self::convertToClassName($commandName) . 'Command';
 164
 165                 // Now, let us create the full name of the command class
 166                 $this->setClassName($className);
 167
 168                 // Is this class already loaded?
 169                 if (class_exists($this->getClassName())) {
 170                         // This class does exist. :-)
 171                         $isValid = TRUE;
 172                 } // END - if
 173
 174                 // Set command name
 175                 $this->setCommandName($commandName);
 176
 177                 // Return the result
 178                 return $isValid;
 179         }
 180
 181 }