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 use Org\Mxchange\CoreFramework\Utils\String\StringUtils;
  13
  14 // Import SPL stuff
  15 use \InvalidArgumentException;
  16 use \UnexpectedValueException;
  17
  18 /**
  19  * A generic command resolver class
  20  *
  21  * @author              Roland Haeder <webmaster@shipsimu.org>
  22  * @version             0.0.0
  23  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2020 Core Developer Team
  24  * @license             GNU GPL 3.0 or any newer version
  25  * @link                http://www.shipsimu.org
  26  *
  27  * This program is free software: you can redistribute it and/or modify
  28  * it under the terms of the GNU General Public License as published by
  29  * the Free Software Foundation, either version 3 of the License, or
  30  * (at your option) any later version.
  31  *
  32  * This program is distributed in the hope that it will be useful,
  33  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  34  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  35  * GNU General Public License for more details.
  36  *
  37  * You should have received a copy of the GNU General Public License
  38  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  39  */
  40 abstract class BaseCommandResolver extends BaseResolver {
  41         /**
  42          * Command name
  43          */
  44         private $commandName = '';
  45
  46         /**
  47          * Protected constructor
  48          *
  49          * @param       $className      Name of the class
  50          * @return      void
  51          */
  52         protected function __construct (string $className) {
  53                 // Call parent constructor
  54                 parent::__construct($className);
  55         }
  56
  57         /**
  58          * Setter for command name
  59          *
  60          * @param       $commandName    Last validated command name
  61          * @return      void
  62          */
  63         protected final function setCommandName (string $commandName) {
  64                 $this->commandName = $commandName;
  65         }
  66
  67         /**
  68          * Getter for command name
  69          *
  70          * @return      $commandName    Last validated command name
  71          */
  72         protected final function getCommandName () {
  73                 return $this->commandName;
  74         }
  75
  76         /**
  77          * "Loads" a given command and instances it if not yet cached
  78          *
  79          * @param       $commandName                            A command name we shall look for
  80          * @return      $commandInstance                        A loaded command instance
  81          * @throws      InvalidCommandException         Thrown if even the default
  82          *                                                                              command class is missing (bad!)
  83          */
  84         protected function loadCommand ($commandName) {
  85                 // Init command instance
  86                 $commandInstance = NULL;
  87
  88                 // Create class name
  89                 $className = sprintf(
  90                         '%s\%s%sCommand',
  91                         $this->getNamespace(),
  92                         $this->getCapitalizedClassPrefix(),
  93                         StringUtils::convertToClassName($commandName)
  94                 );
  95
  96                 // Create command class name
  97                 $this->setClassName($className);
  98
  99                 // Is this class loaded?
 100                 if (!class_exists($this->getClassName())) {
 101                         // Class not found, so throw an exception
 102                         throw new InvalidCommandException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
 103                 } // END - if
 104
 105                 // Initiate the command
 106                 $commandInstance = ObjectFactory::createObjectByName($this->getClassName(), array($this));
 107
 108                 // Return the result
 109                 return $commandInstance;
 110         }
 111
 112         /**
 113          * Returns an command instance for a given request class or null if
 114          * it was not found
 115          *
 116          * @param       $requestInstance        An instance of a Requestable class
 117          * @return      $commandInstance        An instance of the resolved command
 118          * @throws      InvalidCommandException         Thrown if $commandName is invalid
 119          * @throws      UnexpectedValueException        Thrown if $commandInstance is an invalid instance
 120          */
 121         public function resolveCommandByRequest (Requestable $requestInstance) {
 122                 // Init variables
 123                 $commandName = '';
 124                 $commandInstance = NULL;
 125
 126                 // This goes fine so let's resolve the command
 127                 $commandName = $requestInstance->getRequestElement('command');
 128
 129                 // Is the command empty? Then fall back to default command
 130                 if (empty($commandName)) {
 131                         $commandName = FrameworkBootstrap::getConfigurationInstance()->getConfigEntry('default_' . FrameworkBootstrap::getRequestTypeFromSystem() . '_command');
 132                 } // END - if
 133
 134                 // Check if command is valid
 135                 if ($this->isCommandValid($this->getNamespace(), $commandName) === false) {
 136                         // This command is invalid!
 137                         throw new InvalidCommandException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
 138                 } // END - if
 139
 140                 // Get the command
 141                 $commandInstance = $this->loadCommand($commandName);
 142
 143                 // And validate it
 144                 if ((!is_object($commandInstance)) || (!$commandInstance instanceof Commandable)) {
 145                         // This command has an invalid instance!
 146                         throw new UnexpectedValueException(sprintf('commandInstance for commandName=%s is not object (%s) or does not implement Commandable.', $commandName, gettype($commandInstance)), self::EXCEPTION_INVALID_COMMAND);
 147                 } // END - if
 148
 149                 // Set last command
 150                 $this->setResolvedInstance($commandInstance);
 151
 152                 // Return the resolved command instance
 153                 return $commandInstance;
 154         }
 155
 156         /**
 157          * Resolves the command by its direct name and returns an instance of its class
 158          *
 159          * @param       $namespace                      Namespace to look in
 160          * @param       $commandName            The direct command name we shall resolve
 161          * @return      $commandInstance        An instance of the command class
 162          * @throws      InvalidCommandException         Thrown if $commandName is invalid
 163          */
 164         public function resolveCommand ($namespace, $commandName) {
 165                 // Is a action set?
 166                 if (empty($namespace)) {
 167                         // Then thrown an exception here
 168                         throw new InvalidArgumentException('Parameter "namespace" is empty');
 169                 } elseif (empty($commandName)) {
 170                         // Then thrown an exception here
 171                         throw new InvalidArgumentException('Parameter "commandName" is empty');
 172                 }
 173
 174                 // Initiate the instance variable
 175                 $commandInstance = NULL;
 176
 177                 // Is the command empty? Then fall back to default command
 178                 if (empty($commandName)) {
 179                         // Init default command
 180                         $commandName = FrameworkBootstrap::getConfigurationInstance()->getConfigEntry('default_' . FrameworkBootstrap::getRequestTypeFromSystem() . '_command');
 181                 } // END - if
 182
 183                 // Check if command is valid
 184                 if ($this->isCommandValid($namespace, $commandName) === false) {
 185                         // This command is invalid!
 186                         throw new InvalidCommandException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
 187                 } // END - if
 188
 189                 // Get the command
 190                 $commandInstance = $this->loadCommand($commandName);
 191
 192                 // Return the instance
 193                 return $commandInstance;
 194         }
 195
 196         /**
 197          * Checks whether the given command is valid
 198          *
 199          * @param       $namespace              Namespace to look in
 200          * @param       $commandName    The default command we shall execute
 201          * @return      $isValid                Whether the given command is valid
 202          * @throws      InvalidArgumentException        Thrown if given command is not set
 203          */
 204         protected function isCommandValid ($namespace, $commandName) {
 205                 // Is namespace and command name set?
 206                 if (empty($namespace)) {
 207                         // Then thrown an exception here
 208                         throw new InvalidArgumentException('Parameter "namespace" is empty');
 209                 } elseif (empty($commandName)) {
 210                         // Then thrown an exception here
 211                         throw new InvalidArgumentException('Parameter "commandName" is empty');
 212                 }
 213
 214                 // By default nothing shall be valid
 215                 $isValid = false;
 216
 217                 // Create the full class name
 218                 $className = sprintf(
 219                         '%s\%s%sCommand',
 220                         $namespace,
 221                         $this->getCapitalizedClassPrefix(),
 222                         StringUtils::convertToClassName($commandName)
 223                 );
 224
 225                 // Now, let us create the full name of the command class
 226                 $this->setClassName($className);
 227
 228                 // Is this class already loaded?
 229                 if (class_exists($this->getClassName())) {
 230                         // This class does exist. :-)
 231                         $isValid = true;
 232                 } // END - if
 233
 234                 // Set command name
 235                 $this->setCommandName($commandName);
 236
 237                 // Return the result
 238                 return $isValid;
 239         }
 240
 241 }