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          * Private 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("Lokaler Kommandoaufl&ouml;ser");
  41
  42                 // Create unique ID number
  43                 $this->createUniqueID();
  44
  45                 // Clean up a little
  46                 $this->removeNumberFormaters();
  47                 $this->removeSystemArray();
  48
  49                 // Set prefix to "Web"
  50                 $this->setCommandPrefix("Web");
  51         }
  52
  53         /**
  54          * Creates an instance of a Web command resolver with a given default command
  55          *
  56          * @param       $defaultCommand                         The default command we shall execute
  57          * @param       $appInstance                            An instance of a manageable application helper class
  58          * @return      $resolverInstance                       The prepared command resolver instance
  59          * @throws      EmptyVariableException          Thrown if the default command is not set
  60          * @throws      InvalidCommandException         Thrown if the default command is invalid
  61          */
  62         public final static function createWebCommandResolver ($defaultCommand, ManageableApplication $appInstance) {
  63                 // Create the new instance
  64                 $resolverInstance = new WebCommandResolver();
  65
  66                 // Is the variable $defaultCommand set and the command is valid?
  67                 if (empty($defaultCommand)) {
  68                         // Then thrown an exception here
  69                         throw new EmptyVariableException(array($resolverInstance, 'defaultCommand'), self::EXCEPTION_UNEXPECTED_EMPTY_STRING);
  70                 } elseif (!$resolverInstance->isCommandValid($defaultCommand)) {
  71                         // Invalid command found
  72                         throw new InvalidCommandException(array($resolverInstance, $defaultCommand), self::EXCEPTION_INVALID_COMMAND);
  73                 }
  74
  75                 // Set the application instance
  76                 $resolverInstance->setApplicationInstance($appInstance);
  77
  78                 // Return the prepared instance
  79                 return $resolverInstance;
  80         }
  81
  82         /**
  83          * Returns an command instance for a given request class or null if
  84          * MissingArrayElementsException was thrown
  85          *
  86          * @param       $requestInstance        An instance of a request class
  87          * @return      $commandInstance        An instance of the resolved command
  88          * @throws      InvalidCommandException                         Thrown if $commandName is
  89          *                                                                                              invalid
  90          * @throws      InvalidCommandInstanceException         Thrown if $commandInstance
  91          *                                                                                              is an invalid instance
  92          */
  93         public function resolvCommandByRequest (Requestable $requestInstance) {
  94                 // Init variables
  95                 $commandName = "";
  96                 $commandInstance = null;
  97
  98                 // Test if the required parameter is set
  99                 try {
 100                         // This goes fine so let's resolv the command
 101                         $commandName = $requestInstance->getRequestElement($this->getConfigInstance()->readConfig("command_parameter"));
 102
 103                         // Is the command empty? Then fall back to default command
 104                         if (empty($commandName)) $commandName = $this->getConfigInstance()->readConfig("default_command");
 105
 106                         // Check if the command is valid
 107                         if (!$this->isCommandValid($commandName)) {
 108                                 // This command is invalid!
 109                                 throw new InvalidCommandException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
 110                         }
 111
 112                         // Get the command
 113                         $commandInstance = $this->loadCommand($commandName);
 114
 115                         // And validate it
 116                         if ((!is_object($commandInstance)) || (!$commandInstance instanceof Commandable)) {
 117                                 // This command has an invalid instance!
 118                                 throw new InvalidCommandInstanceException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
 119                         }
 120
 121                         // Set last command
 122                         $this->lastCommandInstance = $commandInstance;
 123                 } catch (MissingArrayElementsException $e) {
 124                         // Just catch it here...
 125                 }
 126
 127                 // Return the resolved command instance
 128                 return $commandInstance;
 129         }
 130
 131         /**
 132          * "Loads" a given command and instances it if not yet cached
 133          *
 134          * @param       $commandName                            A command name we shall look for
 135          * @return      $commandInstance                        A loaded command instance
 136          * @throws      InvalidCommandException         Thrown if even the default
 137          *                                                                              command class is missing (bad!)
 138          */
 139         private function loadCommand ($commandName) {
 140                 // Cache default command
 141                 $defaultCommand = $this->getConfigInstance()->readConfig("default_command");
 142
 143                 // Init command instance
 144                 $commandInstance = null;
 145
 146                 // Create command class name
 147                 $class = sprintf("Web%sCommand",
 148                         ucfirst(strtolower($commandName))
 149                 );
 150
 151                 // Is this class loaded?
 152                 if (!class_exists($class)) {
 153                         // Class not found, so try the default one or throw exception
 154                         if ($commandName != $defaultCommand) {
 155                                 // Try the default command
 156                                 return $this->loadCommand($defaultCommand);
 157                         } else {
 158                                 // Still not found?
 159                                 throw new InvalidCommandException(array($this, $defaultCommand), self::EXCEPTION_INVALID_COMMAND);
 160                         }
 161                 }
 162
 163                 // Initiate the command
 164                 $eval = sprintf("\$commandInstance = %s::create%s(\$this);",
 165                         $class,
 166                         $class
 167                 );
 168
 169                 // Run the command
 170                 eval($eval);
 171
 172                 // Is the instance valid?
 173                 if ((!is_object($commandInstance)) || (!$commandInstance instanceof Commandable)) {
 174                         // Something is wrong
 175                         $commandInstance = null;
 176                 }
 177
 178                 // Return the result
 179                 return $commandInstance;
 180         }
 181 }
 182
 183 // [EOF]
 184 ?>