State (see State Pattern) prepared, a lot reworked/refactured
[core.git] / inc / classes / main / resolver / command / web / class_
1 <?php
2 /**
3  * A command resolver for local (non-hubbed) web commands
4  *
5  * @author              Roland Haeder <webmaster@ship-simu.org>
6  * @version             0.0.0
7  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 Core Developer Team
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 Web???CommandResolver extends BaseCommandResolver implements CommandResolver {
25         /**
26          * Last successfull resolved command
27          */
28         private $lastCommandInstance = null;
29
30         /**
31          * Protected constructor
32          *
33          * @return      void
34          */
35         protected function __construct () {
36                 // Call parent constructor
37                 parent::__construct(__CLASS__);
38
39                 // Set prefix to 'Web'
40                 $this->setCommandPrefix('Web');
41         }
42
43         /**
44          * Creates an instance of a Web command resolver with a given default command
45          *
46          * @param       $commandName                            The default command we shall execute
47          * @param       $appInstance                            An instance of a manageable application helper class
48          * @return      $resolverInstance                       The prepared command resolver instance
49          * @throws      EmptyVariableException          Thrown if the default command is not set
50          * @throws      InvalidCommandException         Thrown if the default command is invalid
51          */
52         public final static function createWeb???CommandResolver ($commandName, ManageableApplication $appInstance) {
53                 // Create the new instance
54                 $resolverInstance = new Web???CommandResolver();
55
56                 // Is the variable $commandName set and the command is valid?
57                 if (empty($commandName)) {
58                         // Then thrown an exception here
59                         throw new EmptyVariableException(array($resolverInstance, 'commandName'), self::EXCEPTION_UNEXPECTED_EMPTY_STRING);
60                 } elseif ($resolverInstance->isCommandValid($commandName) === false) {
61                         // Invalid command found
62                         throw new InvalidCommandException(array($resolverInstance, $commandName), self::EXCEPTION_INVALID_COMMAND);
63                 }
64
65                 // Set the application instance
66                 $resolverInstance->setApplicationInstance($appInstance);
67
68                 // Return the prepared instance
69                 return $resolverInstance;
70         }
71
72         /**
73          * Returns an command instance for a given request class or null if
74          * it was not found
75          *
76          * @param       $requestInstance        An instance of a request class
77          * @return      $commandInstance        An instance of the resolved command
78          * @throws      InvalidCommandException                         Thrown if $commandName is
79          *                                                                                              invalid
80          * @throws      InvalidCommandInstanceException         Thrown if $commandInstance
81          *                                                                                              is an invalid instance
82          */
83         public function resolveCommandByRequest (Requestable $requestInstance) {
84                 // Init variables
85                 $commandName = "";
86                 $commandInstance = null;
87
88                 // This goes fine so let's resolv the command
89                 $commandName = $requestInstance->getRequestElement('page');
90
91                 // Is the command empty? Then fall back to default command
92                 if (empty($commandName)) $commandName = $this->getConfigInstance()->readConfig('default_web_command');
93
94                 // Check if the command is valid
95                 if ($this->isCommandValid($commandName) === false) {
96                         // This command is invalid!
97                         throw new InvalidCommandException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
98                 } // END - if
99
100                 // Get the command
101                 $commandInstance = $this->loadCommand($commandName);
102
103                 // And validate it
104                 if ((!is_object($commandInstance)) || (!$commandInstance instanceof Commandable)) {
105                         // This command has an invalid instance!
106                         throw new InvalidCommandInstanceException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
107                 } // END - if
108
109                 // Set last command
110                 $this->lastCommandInstance = $commandInstance;
111
112                 // Return the resolved command instance
113                 return $commandInstance;
114         }
115
116         /**
117          * Resolves the command by its direct name and returns an instance of its class
118          *
119          * @param       $commandName            The direct command name we shall resolve
120          * @return      $commandInstance        An instance of the command class
121          * @throws      InvalidCommandException         Thrown if $commandName is invalid
122          */
123         public function resolveCommand ($commandName) {
124                 // Initiate the instance variable
125                 $commandInstance = null;
126
127                 // Is the command empty? Then fall back to default command
128                 if (empty($commandName)) $commandName = $this->getConfigInstance()->readConfig('default_web_command');
129
130                 // Check if the command is valid
131                 if ($this->isCommandValid($commandName) === false) {
132                         // This command is invalid!
133                         throw new InvalidCommandException(array($this, $commandName), self::EXCEPTION_INVALID_COMMAND);
134                 }
135
136                 // Get the command
137                 $commandInstance = $this->loadCommand($commandName);
138
139                 // Return the instance
140                 return $commandInstance;
141         }
142
143         /**
144          * "Loads" a given command and instances it if not yet cached
145          *
146          * @param       $commandName                            A command name we shall look for
147          * @return      $commandInstance                        A loaded command instance
148          * @throws      InvalidCommandException         Thrown if even the default
149          *                                                                              command class is missing (bad!)
150          */
151         private function loadCommand ($commandName) {
152                 // Cache default command
153                 $defaultCommand = $this->getConfigInstance()->readConfig('default_web_command');
154
155                 // Init command instance
156                 $commandInstance = null;
157
158                 // Create command class name
159                 $this->setClassName(sprintf("Web%sCommand",
160                         $this->convertToClassName($commandName)
161                 ));
162
163                 // Is this class loaded?
164                 if (!class_exists($this->getClassName())) {
165                         // Class not found, so throw an exception
166                         throw new InvalidCommandException(array($this, $defaultCommand), self::EXCEPTION_INVALID_COMMAND);
167                 } // END - if
168
169                 // Initiate the command
170                 $commandInstance = ObjectFactory::createObjectByName($this->getClassName(), array($this));
171
172                 // Return the result
173                 return $commandInstance;
174         }
175 }
176
177 // [EOF]
178 ?>