framework/bootstrap/class_FrameworkBootstrap.php

   1 <?php
   2 // Own namespace
   3 namespace CoreFramework\Bootstrap;
   4
   5 // Import framework stuff
   6 use CoreFramework\Configuration\FrameworkConfiguration;
   7 use CoreFramework\Connection\Database\DatabaseConnection;
   8 use CoreFramework\Connector\Database\DatabaseConnector;
   9 use CoreFramework\Console\Tools\ConsoleTools;
  10 use CoreFramework\EntryPoint\ApplicationEntryPoint;
  11 use CoreFramework\Factory\ObjectFactory;
  12 use CoreFramework\Generic\NullPointerException;
  13 use CoreFramework\Helper\Application\ApplicationHelper;
  14 use CoreFramework\Loader\ClassLoader;
  15 use CoreFramework\Manager\ManageableApplication;
  16 use CoreFramework\Middleware\Debug\DebugMiddleware;
  17 use CoreFramework\Object\BaseFrameworkSystem;
  18 use CoreFramework\Registry\Registry;
  19 use CoreFramework\Request\Requestable;
  20 use CoreFramework\Response\Responseable;
  21
  22 // Import SPL stuff
  23 use \BadMethodCallException;
  24 use \InvalidArgumentException;
  25 use \SplFileInfo;
  26
  27 /**
  28  * A framework-bootstrap class which helps the frameworks to bootstrap ... ;-)
  29  *
  30  * @author              Roland Haeder <webmaster@ship-simu.org>
  31  * @version             0.0.0
  32  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2017 Core Developer Team
  33  * @license             GNU GPL 3.0 or any newer version
  34  * @link                http://www.ship-simu.org
  35  *
  36  * This program is free software: you can redistribute it and/or modify
  37  * it under the terms of the GNU General Public License as published by
  38  * the Free Software Foundation, either version 3 of the License, or
  39  * (at your option) any later version.
  40  *
  41  * This program is distributed in the hope that it will be useful,
  42  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  43  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  44  * GNU General Public License for more details.
  45  *
  46  * You should have received a copy of the GNU General Public License
  47  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  48  */
  49 final class FrameworkBootstrap {
  50
  51         /**
  52          * Detected server address
  53          */
  54         private static $serverAddress = NULL;
  55
  56         /**
  57          * Instance of a Requestable class
  58          */
  59         private static $requestInstance = NULL;
  60
  61         /**
  62          * Instance of a Responseable class
  63          */
  64         private static $responseInstance = NULL;
  65
  66         /**
  67          * Instance of a FrameworkConfiguration class
  68          */
  69         private static $configurationInstance = NULL;
  70
  71         /*
  72          * Includes applications may have. They will be tried in the given order,
  73          * some will become soon deprecated.
  74          */
  75         private static $configAppIncludes = array(
  76                 // The ApplicationHelper class (required)
  77                 'class_ApplicationHelper' => 'required',
  78                 // Some debugging stuff (optional but can be committed)
  79                 'debug'                   => 'optional',
  80                 // Application's exception handler (optional but can be committed)
  81                 'exceptions'              => 'optional',
  82                 // Application's configuration file (committed, non-local specific)
  83                 'config'                  => 'required',
  84                 // Local configuration file (optional, not committed, listed in .gitignore)
  85                 'config-local'            => 'optional',
  86                 // Application data (deprecated)
  87                 'data'                    => 'deprecated',
  88                 // Application loader (deprecated)
  89                 'loader'                  => 'deprecated',
  90                 // Application initializer (deprecated)
  91                 'init'                    => 'deprecated',
  92                 // Application starter (deprecated)
  93                 'starter'                 => 'deprecated',
  94         );
  95
  96         /**
  97          * Private constructor, no instance is needed from this class as only
  98          * static methods exist.
  99          */
 100         private function __construct () {
 101                 // Prevent making instances from this "utilities" class
 102         }
 103
 104         /**
 105          * Some "getter" for a configuration instance, making sure, it is unique
 106          *
 107          * @return      $configurationInstance  An instance of a FrameworkConfiguration class
 108          */
 109         public static function getConfigurationInstance () {
 110                 // Is the instance there?
 111                 if (is_null(self::$configurationInstance)) {
 112                         // Init new instance
 113                         self::$configurationInstance = new FrameworkConfiguration();
 114                 } // END - if
 115
 116                 // Return it
 117                 return self::$configurationInstance;
 118         }
 119
 120         /**
 121          * Getter for request instance
 122          *
 123          * @return      $requestInstance        An instance of a Requestable class
 124          */
 125         public static function getRequestInstance () {
 126                 return self::$requestInstance;
 127         }
 128
 129         /**
 130          * Getter for response instance
 131          *
 132          * @return      $responseInstance       An instance of a Responseable class
 133          */
 134         public static function getResponseInstance () {
 135                 return self::$responseInstance;
 136         }
 137
 138         /**
 139          * "Getter" to get response/request type from analysis of the system.
 140          *
 141          * @return      $requestType    Analyzed request type
 142          */
 143         public static function getRequestTypeFromSystem () {
 144                 // Default is console
 145                 $requestType = 'console';
 146
 147                 // Is 'HTTP_HOST' set?
 148                 if (isset($_SERVER['HTTP_HOST'])) {
 149                         // Then it is a HTML response/request.
 150                         $requestType = 'html';
 151                 } // END - if
 152
 153                 // Return it
 154                 return $requestType;
 155         }
 156
 157         /**
 158          * Checks whether the given file/path is in open_basedir(). This does not
 159          * gurantee that the file is actually readable and/or writeable. If you need
 160          * such gurantee then please use isReadableFile() instead.
 161          *
 162          * @param       $fileInstance   An instance of a SplFileInfo class
 163          * @return      $isReachable    Whether it is within open_basedir()
 164          */
 165         public static function isReachableFilePath (SplFileInfo $fileInstance) {
 166                 // Is not reachable by default
 167                 $isReachable = false;
 168
 169                 // Get open_basedir parameter
 170                 $openBaseDir = trim(ini_get('open_basedir'));
 171
 172                 // Is it set?
 173                 if (!empty($openBaseDir)) {
 174                         // Check all entries
 175                         foreach (explode(PATH_SEPARATOR, $openBaseDir) as $dir) {
 176                                 // Check on existence
 177                                 if (substr($fileInstance->getPathname(), 0, strlen($dir)) == $dir) {
 178                                         // Is reachable
 179                                         $isReachable = true;
 180
 181                                         // Abort lookup as it has been found in open_basedir
 182                                         break;
 183                                 } // END - if
 184                         } // END - foreach
 185                 } else {
 186                         // If open_basedir is not set, all is allowed
 187                         $isReachable = true;
 188                 }
 189
 190                 // Return status
 191                 return $isReachable;
 192         }
 193
 194         /**
 195          * Checks whether the give file is within open_basedir() (done by
 196          * isReachableFilePath()), is actually a file and is readable.
 197          *
 198          * @param       $fileInstance   An instance of a SplFileInfo class
 199          * @return      $isReadable             Whether the file is readable (and therefor exists)
 200          */
 201         public static function isReadableFile (SplFileInfo $fileInstance) {
 202                 // Default is not readable
 203                 $isReadable = false;
 204
 205                 // Check if it is a file and readable
 206                 $isReadable = (
 207                         (
 208                                 self::isReachableFilePath($fileInstance)
 209                         ) && (
 210                                 $fileInstance->isFile()
 211                         ) && (
 212                                 $fileInstance->isReadable()
 213                         )
 214                 );
 215
 216                 // Return status
 217                 return $isReadable;
 218         }
 219
 220         /**
 221          * Loads given include file
 222          *
 223          * @param       $fileInstance   An instance of a SplFileInfo class
 224          * @return      void
 225          * @throws      InvalidArgumentException        If file was not found or not readable or deprecated
 226          */
 227         public static function loadInclude (SplFileInfo $fileInstance) {
 228                 // Trace message
 229                 //* NOISY-DEBUG: */ printf('[%s:%d]: fileInstance=%s - CALLED!' . PHP_EOL, __METHOD__, __LINE__, $fileInstance);
 230
 231                 // Should be there ...
 232                 if (!self::isReadableFile($fileInstance)) {
 233                         // Abort here
 234                         throw new InvalidArgumentException(sprintf('Cannot find fileInstance.pathname=%s.', $fileInstance->getPathname()));
 235                 } // END - if
 236
 237                 // Load it
 238                 require $fileInstance->getPathname();
 239
 240                 // Trace message
 241                 //* NOISY-DEBUG: */ printf('[%s:%d]: EXIT!' . PHP_EOL, __METHOD__, __LINE__);
 242         }
 243
 244         /**
 245          * Does the actual bootstrap
 246          *
 247          * @return      void
 248          */
 249         public static function doBootstrap () {
 250                 // Load basic include files to continue bootstrapping
 251                 self::loadInclude(new SplFileInfo(sprintf('%smain%sinterfaces%sclass_FrameworkInterface.php', ApplicationEntryPoint::detectFrameworkPath(), DIRECTORY_SEPARATOR, DIRECTORY_SEPARATOR)));
 252                 self::loadInclude(new SplFileInfo(sprintf('%smain%sclasses%sclass_BaseFrameworkSystem.php', ApplicationEntryPoint::detectFrameworkPath(), DIRECTORY_SEPARATOR, DIRECTORY_SEPARATOR)));
 253                 self::loadInclude(new SplFileInfo(sprintf('%smain%sinterfaces%sregistry%sclass_Registerable.php', ApplicationEntryPoint::detectFrameworkPath(), DIRECTORY_SEPARATOR, DIRECTORY_SEPARATOR, DIRECTORY_SEPARATOR)));
 254                 self::loadInclude(new SplFileInfo(sprintf('%sconfig%sclass_FrameworkConfiguration.php', ApplicationEntryPoint::detectFrameworkPath(), DIRECTORY_SEPARATOR)));
 255
 256                 // Load global configuration
 257                 self::loadInclude(new SplFileInfo(sprintf('%s%s', ApplicationEntryPoint::detectFrameworkPath(), 'config-global.php')));
 258         }
 259
 260         /**
 261          * Initializes the framework by scanning for all framework-relevant
 262          * classes, interfaces and exception. Then determine the request type and
 263          * initialize a Requestable instance which will then contain all request
 264          * parameter, also from CLI. Next step is to validate the application
 265          * (very basic).
 266          *
 267          * @return      void
 268          */
 269         public static function initFramework () {
 270                 /**
 271                  * 1) Load class loader and scan framework classes, interfaces and
 272                  *    exceptions.
 273                  */
 274                 self::scanFrameworkClasses();
 275
 276                 /*
 277                  * 2) Determine the request type, console or web and store request and
 278                  *    response here. This also initializes the request instance will
 279                  *    all given parameters (see doc-tag for possible sources of
 280                  *    parameters).
 281                  */
 282                 self::determineRequestType();
 283
 284                 /*
 285                  * 3) Now, that there are all request parameters being available, check
 286                  *    if 'app' is supplied. If it is not found, abort execution, if
 287                  *    found, continue below with next step.
 288                  */
 289                 self::validateApplicationParameter();
 290         }
 291
 292         /**
 293          * Initializes the detected application. This may fail if required files
 294          * are not found in the application's base path (not to be confused with
 295          * 'application_base_path' which only points to /some/foo/application/.
 296          *
 297          * @return      void
 298          */
 299         public static function prepareApplication () {
 300                 // Configuration entry 'detected_app_name' must be set, get it here, including full path
 301                 $application = self::getConfigurationInstance()->getConfigEntry('detected_app_name');
 302                 $fullPath    = self::getConfigurationInstance()->getConfigEntry('detected_full_app_path');
 303
 304                 /*
 305                  * Now check and load all files, found deprecated files will throw a
 306                  * warning at the user.
 307                  */
 308                 foreach (self::$configAppIncludes as $fileName => $status) {
 309                         // Construct file instance
 310                         $fileInstance = new SplFileInfo(sprintf('%s%s.php', $fullPath, $fileName));
 311
 312                         // Determine if this file is wanted/readable/deprecated
 313                         if (($status == 'required') && (!self::isReadableFile($fileInstance))) {
 314                                 // Nope, required file cannot be found/read from
 315                                 ApplicationEntryPoint::exitApplication(sprintf('Application "%s" does not have required file "%s.php". Please add it.', $application, $fileInstance->getBasename()));
 316                         } elseif (($fileInstance->isFile()) && (!$fileInstance->isReadable())) {
 317                                 // Found, not readable file
 318                                 ApplicationEntryPoint::exitApplication(sprintf('File "%s.php" from application "%s" cannot be read. Please fix CHMOD.', $fileInstance->getBasename(), $application));
 319                         } elseif (($status != 'required') && (!self::isReadableFile($fileInstance))) {
 320                                 // Not found but optional/deprecated file, skip it
 321                                 continue;
 322                         }
 323
 324                         // Is the file deprecated?
 325                         if ($status == 'deprecated') {
 326                                 // Issue warning
 327                                 trigger_error(sprintf('Deprecated file "%s.php" found, will not load it to avoid problems. Please remove it from your application "%s" to avoid this warning.', $fileName, $application), E_USER_WARNING);
 328
 329                                 // Skip loading deprecated file
 330                                 continue;
 331                         } // END - if
 332
 333                         // Load it
 334                         self::loadInclude($fileInstance);
 335                 } // END - foreach
 336
 337                 // Scan for application's classes, exceptions and interfaces
 338                 ClassLoader::scanApplicationClasses();
 339         }
 340
 341         /**
 342          * Starts a fully initialized application, the class ApplicationHelper must
 343          * be loaded at this point.
 344          *
 345          * @return      void
 346          */
 347         public static function startApplication () {
 348                 // Configuration entry 'detected_app_name' must be set, get it here
 349                 $application = self::getConfigurationInstance()->getConfigEntry('detected_app_name');
 350
 351                 // Is there an application helper instance?
 352                 $applicationInstance = call_user_func_array(
 353                         array(
 354                                 'CoreFramework\Helper\Application\ApplicationHelper', 'getSelfInstance'
 355                         ), array()
 356                 );
 357
 358                 // Some sanity checks
 359                 if ((empty($applicationInstance)) || (is_null($applicationInstance))) {
 360                         // Something went wrong!
 361                         ApplicationEntryPoint::exitApplication(sprintf('[Main:] The application <span class="app_name">%s</span> could not be launched because the helper class <span class="class_name">%s</span> is not loaded.',
 362                                 $application,
 363                                 'CoreFramework\Helper\Application\ApplicationHelper'
 364                         ));
 365                 } elseif (!is_object($applicationInstance)) {
 366                         // No object!
 367                         ApplicationEntryPoint::exitApplication(sprintf('[Main:] The application <span class="app_name">%s</span> could not be launched because &#39;app&#39; is not an object (%s).',
 368                                 $application,
 369                                 gettype($applicationInstance)
 370                         ));
 371                 } elseif (!($applicationInstance instanceof ManageableApplication)) {
 372                         // Missing interface
 373                         ApplicationEntryPoint::exitApplication(sprintf('[Main:] The application <span class="app_name">%s</span> could not be launched because &#39;app&#39; is lacking required interface ManageableApplication.',
 374                                 $application
 375                         ));
 376                 }
 377
 378                 // Set it in registry
 379                 Registry::getRegistry()->addInstance('app', $applicationInstance);
 380
 381                 // Now call all methods in one go
 382                 foreach (array('setupApplicationData', 'initApplication', 'launchApplication') as $methodName) {
 383                         // Debug message
 384                         //* NOISY-DEBUG: */ printf('[%s:%d]: Calling methodName=%s ...' . PHP_EOL, __METHOD__, __LINE__, $methodName);
 385
 386                         // Call method
 387                         call_user_func(array($applicationInstance, $methodName));
 388                 } // END - foreach
 389         }
 390
 391         /**
 392          * Initializes database instance, no need to double-call this method
 393          *
 394          * @return      void
 395          */
 396         public static function initDatabaseInstance () {
 397                 // Get application instance
 398                 $applicationInstance = ApplicationHelper::getSelfInstance();
 399
 400                 // Is the database instance already set?
 401                 if ($applicationInstance instanceof DatabaseConnector) {
 402                         // Yes, then abort here
 403                         throw new BadMethodCallException('Method called twice.');
 404                 } // END - if
 405
 406                 // Initialize database layer
 407                 $databaseInstance = ObjectFactory::createObjectByConfiguredName(self::getConfigurationInstance()->getConfigEntry('database_type') . '_class');
 408
 409                 // Prepare database instance
 410                 $connectionInstance = DatabaseConnection::createDatabaseConnection(DebugMiddleware::getSelfInstance(), $databaseInstance);
 411
 412                 // Set it in application helper
 413                 $applicationInstance->setDatabaseInstance($connectionInstance);
 414         }
 415
 416         /**
 417          * Detects the server address (SERVER_ADDR) and set it in configuration
 418          *
 419          * @return      $serverAddress  The detected server address
 420          * @throws      UnknownHostnameException        If SERVER_NAME cannot be resolved to an IP address
 421          * @todo        Have to check some more entries from $_SERVER here
 422          */
 423         public static function detectServerAddress () {
 424                 // Is the entry set?
 425                 if (!isset(self::$serverAddress)) {
 426                         // Is it set in $_SERVER?
 427                         if (!empty($_SERVER['SERVER_ADDR'])) {
 428                                 // Set it from $_SERVER
 429                                 self::$serverAddress = $_SERVER['SERVER_ADDR'];
 430                         } elseif (isset($_SERVER['SERVER_NAME'])) {
 431                                 // Resolve IP address
 432                                 $serverIp = ConsoleTools::resolveIpAddress($_SERVER['SERVER_NAME']);
 433
 434                                 // Is it valid?
 435                                 if ($serverIp === false) {
 436                                         /*
 437                                          * Why is gethostbyname() returning the host name and not
 438                                          * false as many other PHP functions are doing? ;-(
 439                                          */
 440                                         throw new UnknownHostnameException(sprintf('Cannot resolve "%s" to an IP address. Please fix your setup.', $_SERVER['SERVER_NAME']));
 441                                 } // END - if
 442
 443                                 // Al fine, set it
 444                                 self::$serverAddress = $serverIp;
 445                         } else {
 446                                 // Run auto-detecting through console tools lib
 447                                 self::$serverAddress = ConsoleTools::acquireSelfIpAddress();
 448                         }
 449                 } // END - if
 450
 451                 // Return it
 452                 return self::$serverAddress;
 453         }
 454
 455         /**
 456          * Setter for default time zone (must be correct!)
 457          *
 458          * @param       $timezone       The timezone string (e.g. Europe/Berlin)
 459          * @return      $success        If timezone was accepted
 460          * @throws      NullPointerException    If $timezone is NULL
 461          * @throws      InvalidArgumentException        If $timezone is empty
 462          */
 463         public static function setDefaultTimezone ($timezone) {
 464                 // Is it null?
 465                 if (is_null($timezone)) {
 466                         // Throw NPE
 467                         throw new NullPointerException(NULL, BaseFrameworkSystem::EXCEPTION_IS_NULL_POINTER);
 468                 } elseif (!is_string($timezone)) {
 469                         // Is not a string
 470                         throw new InvalidArgumentException(sprintf('timezone[]=%s is not a string', gettype($timezone)));
 471                 } elseif ((is_string($timezone)) && (empty($timezone))) {
 472                         // Entry is empty
 473                         throw new InvalidArgumentException('timezone is empty');
 474                 }
 475
 476                 // Default success
 477                 $success = FALSE;
 478
 479                 /*
 480                  * Set desired time zone to prevent date() and related functions to
 481                  * issue an E_WARNING.
 482                  */
 483                 $success = date_default_timezone_set($timezone);
 484
 485                 // Return status
 486                 return $success;
 487         }
 488
 489         /**
 490          * Checks whether HTTPS is set in $_SERVER
 491          *
 492          * @return      $isset  Whether HTTPS is set
 493          * @todo        Test more fields
 494          */
 495         public static function isHttpSecured () {
 496                 return (isset($_SERVER['HTTPS']));
 497         }
 498
 499         /**
 500          * Dectect and return the base URL for all URLs and forms
 501          *
 502          * @return      $baseUrl        Detected base URL
 503          */
 504         public static function detectBaseUrl () {
 505                 // Initialize the URL
 506                 $protocol = 'http';
 507
 508                 // Do we have HTTPS?
 509                 if (self::isHttpSecured()) {
 510                         // Add the >s< for HTTPS
 511                         $protocol = 's';
 512                 } // END - if
 513
 514                 // Construct the full URL and secure it against CSRF attacks
 515                 $baseUrl = sprintf('%s://%s%s', $protocol, self::detectDomain(), self::detectScriptPath());
 516
 517                 // Return the URL
 518                 return $baseUrl;
 519         }
 520
 521         /**
 522          * Detect safely and return the full domain where this script is installed
 523          *
 524          * @return      $fullDomain             The detected full domain
 525          */
 526         public static function detectDomain () {
 527                 // Full domain is localnet.invalid by default
 528                 $fullDomain = 'localnet.invalid';
 529
 530                 // Is the server name there?
 531                 if (isset($_SERVER['SERVER_NAME'])) {
 532                         // Detect the full domain
 533                         $fullDomain = htmlentities(strip_tags($_SERVER['SERVER_NAME']), ENT_QUOTES);
 534                 } // END - if
 535
 536                 // Return it
 537                 return $fullDomain;
 538         }
 539
 540         /**
 541          * Detect safely the script path without trailing slash which is the glue
 542          * between "http://your-domain.invalid/" and "script-name.php"
 543          *
 544          * @return      $scriptPath             The script path extracted from $_SERVER['SCRIPT_NAME']
 545          */
 546         public static function detectScriptPath () {
 547                 // Default is empty
 548                 $scriptPath = '';
 549
 550                 // Is the scriptname set?
 551                 if (isset($_SERVER['SCRIPT_NAME'])) {
 552                         // Get dirname from it and replace back-slashes with slashes for lame OSes...
 553                         $scriptPath = str_replace("\\", '/', dirname($_SERVER['SCRIPT_NAME']));
 554                 } // END - if
 555
 556                 // Return it
 557                 return $scriptPath;
 558         }
 559
 560         /**
 561          * 1) Loads class scanner and scans all framework's classes and interfaces.
 562          * This method also registers the class loader's method autoLoad() for the
 563          * SPL auto-load feature. Remember that you can register additional methods
 564          * (not functions, please) for other libraries.
 565          *
 566          * Yes, I know about Composer, but I like to keep my class loader around.
 567          * You can always use mine as long as your classes have a namespace
 568          * according naming-convention: Vendor\Project\Group[\SubGroup]
 569          *
 570          * @return      void
 571          */
 572         private static function scanFrameworkClasses () {
 573                 // Include the class loader function
 574                 require self::getConfigurationInstance()->getConfigEntry('framework_base_path') . 'loader/class_ClassLoader.php';
 575
 576                 // Register auto-load function with the SPL
 577                 spl_autoload_register('CoreFramework\Loader\ClassLoader::autoLoad');
 578
 579                 // Scan for all framework classes, exceptions and interfaces
 580                 ClassLoader::scanFrameworkClasses();
 581         }
 582
 583         /**
 584          * 2) Determines request/response type and stores the created
 585          * request/response instances in this object for later usage.
 586          *
 587          * @return      void
 588          */
 589         private static function determineRequestType () {
 590                 // Determine request type
 591                 $request = self::getRequestTypeFromSystem();
 592                 $requestType = self::getRequestTypeFromSystem();
 593
 594                 // Create a new request object
 595                 $requestInstance = ObjectFactory::createObjectByName(sprintf('CoreFramework\Request\%sRequest', BaseFrameworkSystem::convertToClassName($request)));
 596
 597                 // Remember request instance here
 598                 self::setRequestInstance($requestInstance);
 599
 600                 // Do we have another response?
 601                 if ($requestInstance->isRequestElementSet('request')) {
 602                         // Then use it
 603                         $request = strtolower($requestInstance->getRequestElement('request'));
 604                         $requestType = $request;
 605                 } // END - if
 606
 607                 // ... and a new response object
 608                 $responseClass = sprintf('CoreFramework\Response\%sResponse', BaseFrameworkSystem::convertToClassName($request));
 609                 $responseInstance = ObjectFactory::createObjectByName($responseClass);
 610
 611                 // Remember response instance here
 612                 self::setResponseInstance($responseInstance);
 613         }
 614
 615         /**
 616          * 3) Validate parameter 'app' if it is set and the application is there.
 617          *
 618          * @return      void
 619          */
 620         private static function validateApplicationParameter () {
 621                 // Is the parameter set?
 622                 if (!self::getRequestInstance()->isRequestElementSet('app')) {
 623                         /*
 624                          * Don't continue here, the application 'selector' is no longer
 625                          * supported and only existed as an idea to select the proper
 626                          * application (by user).
 627                          */
 628                         ApplicationEntryPoint::exitApplication('No application specified. Please provide a parameter "app" and retry.');
 629                 } // END - if
 630
 631                 // Get it for local usage
 632                 $application = self::getRequestInstance()->getRequestElement('app');
 633
 634                 // Secure it, by keeping out tags
 635                 $application = htmlentities(strip_tags($application), ENT_QUOTES);
 636
 637                 // Secure it a little more with a reg.exp.
 638                 $application = preg_replace('/([^a-z0-9_-])+/i', '', $application);
 639
 640                 // Construct FQPN (Full-Qualified Path Name) for ApplicationHelper class
 641                 $applicationPath = sprintf(
 642                         '%s%s%s',
 643                         self::getConfigurationInstance()->getConfigEntry('application_base_path'),
 644                         $application,
 645                         DIRECTORY_SEPARATOR
 646                 );
 647
 648                 // Full path for application
 649                 // Is the path there? This secures a bit the parameter (from untrusted source).
 650                 if ((!is_dir($applicationPath)) || (!is_readable($applicationPath))) {
 651                         // Not found or not readable
 652                         ApplicationEntryPoint::exitApplication(sprintf('Application "%s" not found.', $application));
 653                 } // END - if
 654
 655                 // Set the detected application's name and full path for later usage
 656                 self::getConfigurationInstance()->setConfigEntry('detected_full_app_path', $applicationPath);
 657                 self::getConfigurationInstance()->setConfigEntry('detected_app_name'     , $application);
 658         }
 659         /**
 660          * Setter for request instance
 661          *
 662          * @param       $requestInstance        An instance of a Requestable class
 663          * @return      void
 664          */
 665         private static function setRequestInstance (Requestable $requestInstance) {
 666                 self::$requestInstance = $requestInstance;
 667         }
 668
 669         /**
 670          * Setter for response instance
 671          *
 672          * @param       $responseInstance       An instance of a Responseable class
 673          * @return      void
 674          */
 675         private static function setResponseInstance (Responseable $responseInstance) {
 676                 self::$responseInstance = $responseInstance;
 677         }
 678
 679 }