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

   1 <?php
   2 // Own namespace
   3 namespace Org\Mxchange\CoreFramework\Resolver\Command;
   4
   5 // Import framework stuff
   6 use Org\Mxchange\CoreFramework\Bootstrap\FrameworkBootstrap;
   7 use Org\Mxchange\CoreFramework\Command\Commandable;
   8 use Org\Mxchange\CoreFramework\Command\InvalidCommandException;
   9 use Org\Mxchange\CoreFramework\Factory\ObjectFactory;
  10 use Org\Mxchange\CoreFramework\Request\Requestable;
  11 use Org\Mxchange\CoreFramework\Resolver\BaseResolver;
  12
  13 // Import SPL stuff
  14 use \InvalidArgumentException;
  15 use \UnexpectedValueException;
  16
  17 /**
  18  * A generic command resolver class
  19  *
  20  * @author              Roland Haeder <webmaster@shipsimu.org>
  21  * @version             0.0.0
  22  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2019 Core Developer Team
  23  * @license             GNU GPL 3.0 or any newer version
  24  * @link                http://www.shipsimu.org
  25  *
  26  * This program is free software: you can redistribute it and/or modify
  27  * it under the terms of the GNU General Public License as published by
  28  * the Free Software Foundation, either version 3 of the License, or
  29  * (at your option) any later version.
  30  *
  31  * This program is distributed in the hope that it will be useful,
  32  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  33  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  34  * GNU General Public License for more details.
  35  *
  36  * You should have received a copy of the GNU General Public License
  37  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  38  */
  39 abstract class BaseCommandResolver extends BaseResolver {
  40         /**
  41          * Protected constructor
  42          *
  43          * @param       $className      Name of the class
  44          * @return      void
  45          */
  46         protected function __construct ($className) {
  47                 // Call parent constructor
  48                 parent::__construct($className);
  49         }
  50
  51         /**
  52          * "Loads" a given command and instances it if not yet cached
  53          *
  54          * @param       $commandName                            A command name we shall look for
  55          * @return      $commandInstance                        A loaded command instance
  56          * @throws      InvalidCommandException         Thrown if even the default
  57          *                                                                              command class is missing (bad!)
  58          */
  59         protected function loadCommand ($commandName) {
  60                 // Init command instance
  61                 $commandInstance = NULL;
  62
  63                 // Create class name
  64                 $className = sprintf(
  65                         '%s\%s%sCommand',
  66                         $this->getNamespace(),
  67                         $this->getCapitalizedClassPrefix(),
  68                         self::convertToClassName($commandName)
  69                 );
  70
  71                 // Create command class name
  72                 $this->setClassName($className);
  73
  74                 // Is this class loaded?
  75                 if (!class_exists($this->getClassName())) {
  76                         // Class not found, so throw an exception
  77                         throw new InvalidCommandException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
  78                 } // END - if
  79
  80                 // Initiate the command
  81                 $commandInstance = ObjectFactory::createObjectByName($this->getClassName(), array($this));
  82
  83                 // Return the result
  84                 return $commandInstance;
  85         }
  86
  87         /**
  88          * Returns an command instance for a given request class or null if
  89          * it was not found
  90          *
  91          * @param       $requestInstance        An instance of a Requestable class
  92          * @return      $commandInstance        An instance of the resolved command
  93          * @throws      InvalidCommandException         Thrown if $commandName is invalid
  94          * @throws      UnexpectedValueException        Thrown if $commandInstance is an invalid instance
  95          */
  96         public function resolveCommandByRequest (Requestable $requestInstance) {
  97                 // Init variables
  98                 $commandName = '';
  99                 $commandInstance = NULL;
 100
 101                 // This goes fine so let's resolve the command
 102                 $commandName = $requestInstance->getRequestElement('command');
 103
 104                 // Is the command empty? Then fall back to default command
 105                 if (empty($commandName)) {
 106                         $commandName = $this->getConfigInstance()->getConfigEntry('default_' . FrameworkBootstrap::getRequestTypeFromSystem() . '_command');
 107                 } // END - if
 108
 109                 // Check if command is valid
 110                 if ($this->isCommandValid($this->getNamespace(), $commandName) === false) {
 111                         // This command is invalid!
 112                         throw new InvalidCommandException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
 113                 } // END - if
 114
 115                 // Get the command
 116                 $commandInstance = $this->loadCommand($commandName);
 117
 118                 // And validate it
 119                 if ((!is_object($commandInstance)) || (!$commandInstance instanceof Commandable)) {
 120                         // This command has an invalid instance!
 121                         throw new UnexpectedValueException(sprintf('commandInstance for commandName=%s is not object (%s) or does not implement Commandable.', $commandName, gettype($commandInstance)), self::EXCEPTION_INVALID_COMMAND);
 122                 } // END - if
 123
 124                 // Set last command
 125                 $this->setResolvedInstance($commandInstance);
 126
 127                 // Return the resolved command instance
 128                 return $commandInstance;
 129         }
 130
 131         /**
 132          * Resolves the command by its direct name and returns an instance of its class
 133          *
 134          * @param       $commandName            The direct command name we shall resolve
 135          * @return      $commandInstance        An instance of the command class
 136          * @throws      InvalidCommandException         Thrown if $commandName is invalid
 137          */
 138         public function resolveCommand ($commandName) {
 139                 // Initiate the instance variable
 140                 $commandInstance = NULL;
 141
 142                 // Is the command empty? Then fall back to default command
 143                 if (empty($commandName)) {
 144                         $commandName = $this->getConfigInstance()->getConfigEntry('default_' . FrameworkBootstrap::getRequestTypeFromSystem() . '_command');
 145                 } // END - if
 146
 147                 // Check if command is valid
 148                 if ($this->isCommandValid($commandName) === false) {
 149                         // This command is invalid!
 150                         throw new InvalidCommandException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
 151                 } // END - if
 152
 153                 // Get the command
 154                 $commandInstance = $this->loadCommand($commandName);
 155
 156                 // Return the instance
 157                 return $commandInstance;
 158         }
 159
 160         /**
 161          * Checks whether the given command is valid
 162          *
 163          * @param       $namespace              Namespace to look in
 164          * @param       $commandName    The default command we shall execute
 165          * @return      $isValid                Whether the given command is valid
 166          * @throws      InvalidArgumentException        Thrown if given command is not set
 167          */
 168         protected function isCommandValid ($namespace, $commandName) {
 169                 // By default nothing shall be valid
 170                 $isValid = false;
 171
 172                 // Is namespace and command name set?
 173                 if (empty($namespace)) {
 174                         // Then thrown an exception here
 175                         throw new InvalidArgumentException('Parameter "namespace" is empty');
 176                 } elseif (empty($commandName)) {
 177                         // Then thrown an exception here
 178                         throw new InvalidArgumentException('Parameter "commandName" is empty');
 179                 } // END - if
 180
 181                 // Create the full class name
 182                 $className = sprintf(
 183                         '%s\%s%sCommand',
 184                         $namespace,
 185                         $this->getCapitalizedClassPrefix(),
 186                         self::convertToClassName($commandName)
 187                 );
 188
 189                 // Now, let us create the full name of the command class
 190                 $this->setClassName($className);
 191
 192                 // Is this class already loaded?
 193                 if (class_exists($this->getClassName())) {
 194                         // This class does exist. :-)
 195                         $isValid = true;
 196                 } // END - if
 197
 198                 // Set command name
 199                 $this->setCommandName($commandName);
 200
 201                 // Return the result
 202                 return $isValid;
 203         }
 204
 205 }