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 part description
  40                 $this->setObjectDescription("Resolver for local web commands");
  41
  42                 // Create unique ID number
  43                 $this->generateUniqueId();
  44
  45                 // Set prefix to "Web"
  46                 $this->setCommandPrefix("Web");
  47         }
  48
  49         /**
  50          * Creates an instance of a Web 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      $resolverInstance                       The prepared command resolver instance
  55          * @throws      EmptyVariableException          Thrown if the default command is not set
  56          * @throws      InvalidCommandException         Thrown if the default command is invalid
  57          */
  58         public final static function createWebCommandResolver ($commandName, ManageableApplication $appInstance) {
  59                 // Create the new instance
  60                 $resolverInstance = new WebCommandResolver();
  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($resolverInstance, 'defaultCommand'), self::EXCEPTION_UNEXPECTED_EMPTY_STRING);
  66                 } elseif (!$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          * MissingArrayElementsException was thrown
  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 resolvCommandByRequest (Requestable $requestInstance) {
  90                 // Init variables
  91                 $commandName = "";
  92                 $commandInstance = null;
  93
  94                 // Test if the required parameter is set
  95                 try {
  96                         // This goes fine so let's resolv the command
  97                         $commandName = $requestInstance->getRequestElement($this->getConfigInstance()->readConfig('command_parameter'));
  98
  99                         // Is the command empty? Then fall back to default command
 100                         if (empty($commandName)) $commandName = $this->getConfigInstance()->readConfig('default_command');
 101
 102                         // Check if the command is valid
 103                         if (!$this->isCommandValid($commandName)) {
 104                                 // This command is invalid!
 105                                 throw new InvalidCommandException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
 106                         }
 107
 108                         // Get the command
 109                         $commandInstance = $this->loadCommand($commandName);
 110
 111                         // And validate it
 112                         if ((!is_object($commandInstance)) || (!$commandInstance instanceof Commandable)) {
 113                                 // This command has an invalid instance!
 114                                 throw new InvalidCommandInstanceException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
 115                         }
 116
 117                         // Set last command
 118                         $this->lastCommandInstance = $commandInstance;
 119                 } catch (MissingArrayElementsException $e) {
 120                         // Just catch it here...
 121                 }
 122
 123                 // Return the resolved command instance
 124                 return $commandInstance;
 125         }
 126
 127         /**
 128          * Resolves the command by its direct name and returns an instance of its class
 129          *
 130          * @param       $commandName            The direct command name we shall resolve
 131          * @return      $commandInstance        An instance of the command class
 132          * @throws      InvalidCommandException         Thrown if $commandName is invalid
 133          */
 134         public function resolveCommand ($commandName) {
 135                 // Initiate the instance variable
 136                 $commandInstance = null;
 137
 138                 // Is the command empty? Then fall back to default command
 139                 if (empty($commandName)) $commandName = $this->getConfigInstance()->readConfig('default_command');
 140
 141                 // Check if the command is valid
 142                 if (!$this->isCommandValid($commandName)) {
 143                         // This command is invalid!
 144                         throw new InvalidCommandException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
 145                 }
 146
 147                 // Get the command
 148                 $commandInstance = $this->loadCommand($commandName);
 149
 150                 // Return the instance
 151                 return $commandInstance;
 152         }
 153
 154         /**
 155          * "Loads" a given command and instances it if not yet cached
 156          *
 157          * @param       $commandName                            A command name we shall look for
 158          * @return      $commandInstance                        A loaded command instance
 159          * @throws      InvalidCommandException         Thrown if even the default
 160          *                                                                              command class is missing (bad!)
 161          */
 162         private function loadCommand ($commandName) {
 163                 // Cache default command
 164                 $defaultCommand = $this->getConfigInstance()->readConfig('default_command');
 165
 166                 // Init command instance
 167                 $commandInstance = null;
 168
 169                 // Create command class name
 170                 $className = sprintf("Web%sCommand",
 171                         $this->convertToClassName($commandName)
 172                 );
 173
 174                 // Is this class loaded?
 175                 if (!class_exists($className)) {
 176                         // Class not found, so try the default one or throw exception
 177                         if ($commandName != $defaultCommand) {
 178                                 // Try the default command
 179                                 return $this->loadCommand($defaultCommand);
 180                         } else {
 181                                 // Still not found?
 182                                 throw new InvalidCommandException(array($this, $defaultCommand), self::EXCEPTION_INVALID_COMMAND);
 183                         }
 184                 }
 185
 186                 // Initiate the command
 187                 $eval = sprintf("\$commandInstance = %s::create%s(\$this);",
 188                         $className,
 189                         $className
 190                 );
 191
 192                 // Run the command
 193                 eval($eval);
 194
 195                 // Is the instance valid?
 196                 if ((!is_object($commandInstance)) || (!$commandInstance instanceof Commandable)) {
 197                         // Something is wrong
 198                         $commandInstance = null;
 199                 }
 200
 201                 // Return the result
 202                 return $commandInstance;
 203         }
 204 }
 205
 206 // [EOF]
 207 ?>