framework/main/classes/feature/class_FrameworkFeature.php

   1 <?php
   2 // Own namespace
   3 namespace Org\Mxchange\CoreFramework\Feature;
   4
   5 // Import framework stuff
   6 use Org\Mxchange\CoreFramework\Bootstrap\FrameworkBootstrap;
   7 use Org\Mxchange\CoreFramework\Factory\ObjectFactory;
   8 use Org\Mxchange\CoreFramework\Loader\NoClassException;
   9 use Org\Mxchange\CoreFramework\Object\BaseFrameworkSystem;
  10
  11 /**
  12  * The general feature management class. No instance is needed as this class
  13  * has only public methods that are static.
  14  *
  15  * @author              Roland Haeder <webmaster@ship-simu.org>
  16  * @version             0.0.0
  17 <<<<<<< HEAD:framework/main/classes/feature/class_FrameworkFeature.php
  18  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2017 Core Developer Team
  19 =======
  20  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2016 Core Developer Team
  21 >>>>>>> Some updates::inc/main/classes/feature/class_FrameworkFeature.php
  22  * @license             GNU GPL 3.0 or any newer version
  23  * @link                http://www.ship-simu.org
  24  *
  25  * This program is free software: you can redistribute it and/or modify
  26  * it under the terms of the GNU General Public License as published by
  27  * the Free Software Foundation, either version 3 of the License, or
  28  * (at your option) any later version.
  29  *
  30  * This program is distributed in the hope that it will be useful,
  31  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  32  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  33  * GNU General Public License for more details.
  34  *
  35  * You should have received a copy of the GNU General Public License
  36  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  37  */
  38 class FrameworkFeature extends BaseFrameworkSystem {
  39         // Exception code constants
  40         const EXCEPTION_FEATURE_METHOD_NOT_CALLABLE = 0x400;
  41
  42         /**
  43          * "Cache" for enabled, available feature instances
  44          *
  45          * A typical available entry looks like this:
  46          *
  47          * array(
  48          *     'is_enabled'   => true,
  49          *     'is_available' => true,
  50          *     'instance'     => SomeFeature Object
  51          * )
  52          *
  53          * And a typical disabled entry looks like this:
  54          *
  55          * array(
  56          *     'is_enabled'   => false,
  57          *     'is_available' => false,
  58          *     'instance'     => NULL
  59          * )
  60          */
  61         private static $enabledFeatures = array();
  62
  63         /**
  64          * Protected constructor
  65          *
  66          * @return      void
  67          */
  68         protected function __construct () {
  69                 // Call parent constructor
  70                 parent::__construct(__CLASS__);
  71         }
  72
  73         /**
  74          * Checks whether the given feature is enabled in configuration. The user
  75          * shall be able to disable features, even when they *could* be available.
  76          *
  77          * @param       $featureName    Name of the feature to be checked
  78          * @return      $isEnabled              Whether the given feature is enabled
  79          */
  80         public static function isFeatureEnabled ($featureName) {
  81                 // Is the cache set?
  82                 if (!isset(self::$enabledFeatures[$featureName]['is_enabled'])) {
  83                         // Generate config key
  84                         $configKey = sprintf('enable_feature_%s', $featureName);
  85
  86                         // Check configuration
  87                         self::$enabledFeatures[$featureName]['is_enabled'] = (FrameworkBootstrap::getConfigurationInstance()->getConfigEntry($configKey) === 'Y');
  88                 } // END - if
  89
  90                 // Return "cached" status
  91                 return self::$enabledFeatures[$featureName]['is_enabled'];
  92         }
  93
  94         /**
  95          * Checks whether the given feature is enabled and available. It may be
  96          * enabled by the user, but is not available due to e.g. a missing PECL
  97          * extension or whatever is needed to have this feature available. If you
  98          * don't write a pre filters for checking PHP requirements, this is the
  99          * method you want to use.
 100          *
 101          * @param       $featureName    Name of the feature to be checked on availability
 102          * @return      $isAvailable    Whether the given feature is available
 103          */
 104         public static function isFeatureAvailable ($featureName) {
 105                 // Debug message
 106                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d]: featureName=%s - CALLED!', __METHOD__, __LINE__, $featureName));
 107
 108                 // Is the cache set?
 109                 if (!isset(self::$enabledFeatures[$featureName]['is_available'])) {
 110                         // Default is not available
 111                         self::$enabledFeatures[$featureName]['is_available'] = false;
 112                         self::$enabledFeatures[$featureName]['instance']     = NULL;
 113
 114                         // Is the feature enabled?
 115                         if (!self::isFeatureEnabled($featureName)) {
 116                                 // Then it can't be available
 117                                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d]: Feature "%s"is not enabled.', __METHOD__, __LINE__, $featureName));
 118                                 return false;
 119                         } // END - if
 120
 121                         // Create config key (for feature class lookup)
 122                         $configKey = sprintf('feature_%s_class', $featureName);
 123
 124                         // Debug message
 125                         //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d]: configKey=%s', __METHOD__, __LINE__, $configKey));
 126
 127                         // Now try to get the instance
 128                         try {
 129                                 // Try to get an instance
 130                                 self::$enabledFeatures[$featureName]['instance'] = ObjectFactory::createObjectByConfiguredName($configKey);
 131
 132                                 // Now let the feature test itself's availability
 133                                 self::$enabledFeatures[$featureName]['is_available'] = self::$enabledFeatures[$featureName]['instance']->isFeatureAvailable();
 134                         } catch (NoClassException $e) {
 135                                 // Feature class not found
 136                                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d]: Feature "%s"is not available due to missing feature class. Disabling feature ...', __METHOD__, __LINE__, $featureName));
 137                         }
 138                 } // END - if
 139
 140                 // Debug message
 141                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d]: featureName=%s,isAvailable=%d - EXIT!', __METHOD__, __LINE__, $featureName, intval(self::$enabledFeatures[$featureName]['is_available'])));
 142
 143                 // Return "cached" status
 144                 return self::$enabledFeatures[$featureName]['is_available'];
 145         }
 146
 147         /**
 148          * Calls the feature's method and handles some arguments (if not given,
 149          * NULL) to it. Any returned value is being forwarded to the caller, even
 150          * when the doc-tag says 'void' as returned value.
 151          *
 152          * @param       $featureName    Name of the feature, it must be available at this point
 153          * @param       $featureMethod  Method name of the feature's class
 154          * @param       $args                   Any arguments that should be handled over
 155          * @return      $return                 Anything the feature's method has returned
 156          * @throws      FeatureMethodNotCallableException       If the requested method cannot be called
 157          */
 158         public static function callFeature ($featureName, $featureMethod, array $args = NULL) {
 159                 /*
 160                  * Please make sure that isFeatureAvailable() has been called and it has
 161                  * returned true before calling this method.
 162                  */
 163                 assert(self::isFeatureAvailable($featureName));
 164
 165                 // Array for call-back
 166                 $callable = array(self::$enabledFeatures[$featureName]['instance'], 'featureMethod' . self::convertToClassName($featureMethod));
 167
 168                 // So is the feature's method callable?
 169                 if (!is_callable($callable)) {
 170                         // Not callable method requested
 171                         throw new FeatureMethodNotCallableException(array(self::$enabledFeatures[$featureName]['instance'], $featureMethod), self::EXCEPTION_FEATURE_METHOD_NOT_CALLABLE);
 172                 } // END - if
 173
 174                 // Then call it
 175                 $return = call_user_func_array($callable, $args);
 176
 177                 // Return any returned value
 178                 return $return;
 179         }
 180
 181 }