Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
Complex classes like Session often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use Session, and based on these observations, apply Extract Interface, too.
1 | <?php |
||
10 | class Session{ |
||
|
|||
11 | |||
12 | /** |
||
13 | * constructor for Session Object. |
||
14 | * |
||
15 | * @access private |
||
16 | */ |
||
17 | private function __construct() {} |
||
18 | |||
19 | /** |
||
20 | * Starts the session if not started yet. |
||
21 | * |
||
22 | * @access public |
||
23 | * |
||
24 | */ |
||
25 | public static function init(){ |
||
31 | |||
32 | /** |
||
33 | * Checks if session data exists and valid or not. |
||
34 | * |
||
35 | * @access public |
||
36 | * @static static method |
||
37 | * @param string $ip |
||
38 | * @param string $userAgent |
||
39 | * @return boolean |
||
40 | * |
||
41 | */ |
||
42 | public static function isSessionValid($ip, $userAgent){ |
||
73 | |||
74 | /** |
||
75 | * Get IsLoggedIn value(boolean) |
||
76 | * |
||
77 | * @access public |
||
78 | * @static static method |
||
79 | * @return boolean |
||
80 | * |
||
81 | */ |
||
82 | public static function getIsLoggedIn(){ |
||
85 | |||
86 | /** |
||
87 | * Get User ID. |
||
88 | * |
||
89 | * @access public |
||
90 | * @static static method |
||
91 | * @return string|null |
||
92 | * |
||
93 | */ |
||
94 | public static function getUserId(){ |
||
97 | |||
98 | /** |
||
99 | * Get User Role |
||
100 | * |
||
101 | * @access public |
||
102 | * @static static method |
||
103 | * @return string|null |
||
104 | * |
||
105 | */ |
||
106 | public static function getUserRole(){ |
||
109 | |||
110 | /** |
||
111 | * Get CSRF Token |
||
112 | * |
||
113 | * @access public |
||
114 | * @static static method |
||
115 | * @return string|null |
||
116 | * |
||
117 | */ |
||
118 | public static function getCsrfToken(){ |
||
121 | |||
122 | /** |
||
123 | * Get CSRF Token generated time |
||
124 | * |
||
125 | * @access public |
||
126 | * @static static method |
||
127 | * @return string|null |
||
128 | * |
||
129 | */ |
||
130 | public static function getCsrfTokenTime(){ |
||
133 | |||
134 | /** |
||
135 | * set session key and value |
||
136 | * |
||
137 | * @access public |
||
138 | * @static static method |
||
139 | * @param $key |
||
140 | * @param $value |
||
141 | * |
||
142 | */ |
||
143 | public static function set($key, $value){ |
||
146 | |||
147 | /** |
||
148 | * get session value by $key |
||
149 | * |
||
150 | * @access public |
||
151 | * @static static method |
||
152 | * @param $key |
||
153 | * @return mixed |
||
154 | * |
||
155 | */ |
||
156 | public static function get($key){ |
||
159 | |||
160 | /** |
||
161 | * get session value by $key and destroy it |
||
162 | * |
||
163 | * @access public |
||
164 | * @static static method |
||
165 | * @param $key |
||
166 | * @return mixed |
||
167 | * |
||
168 | */ |
||
169 | public static function getAndDestroy($key){ |
||
182 | |||
183 | /** |
||
184 | * matches current IP Address with the one stored in the session |
||
185 | * |
||
186 | * @access public |
||
187 | * @static static method |
||
188 | * @param string $ip |
||
189 | * @return bool |
||
190 | * |
||
191 | */ |
||
192 | private static function validateIPAddress($ip){ |
||
200 | |||
201 | /** |
||
202 | * matches current user agent with the one stored in the session |
||
203 | * |
||
204 | * @access public |
||
205 | * @static static method |
||
206 | * @param string $userAgent |
||
207 | * @return bool |
||
208 | * |
||
209 | */ |
||
210 | private static function validateUserAgent($userAgent){ |
||
218 | |||
219 | /** |
||
220 | * checks if session has been expired |
||
221 | * |
||
222 | * @access public |
||
223 | * @static static method |
||
224 | * @return bool |
||
225 | * |
||
226 | */ |
||
227 | private static function validateSessionExpiry(){ |
||
237 | |||
238 | /** |
||
239 | * checks for session concurrency |
||
240 | * |
||
241 | * This is done as the following: |
||
242 | * UserA logs in with his session id('123') and it will be stored in the database. |
||
243 | * Then, UserB logs in also using the same email and password of UserA from another PC, |
||
244 | * and also store the session id('456') in the database |
||
245 | * |
||
246 | * Now, Whenever UserA performs any action, |
||
247 | * You then check the session_id() against the last one stored in the database('456'), |
||
248 | * If they don't match then log both of them out. |
||
249 | * |
||
250 | * @access public |
||
251 | * @static static method |
||
252 | * @return bool |
||
253 | * @see Session::updateSessionId() |
||
254 | * @see http://stackoverflow.com/questions/6126285/php-stop-concurrent-user-logins |
||
255 | */ |
||
256 | public static function isConcurrentSessionExists(){ |
||
276 | |||
277 | /** |
||
278 | * get CSRF token and generate a new one if expired |
||
279 | * |
||
280 | * @access public |
||
281 | * @static static method |
||
282 | * @return string |
||
283 | * |
||
284 | */ |
||
285 | public static function generateCsrfToken(){ |
||
299 | |||
300 | /** |
||
301 | * reset session id, delete session file on server, and re-assign the values. |
||
302 | * |
||
303 | * @access public |
||
304 | * @static static method |
||
305 | * @param array $data |
||
306 | * @return string |
||
307 | * |
||
308 | */ |
||
309 | public static function reset($data){ |
||
333 | |||
334 | /** |
||
335 | * update session id in database |
||
336 | * |
||
337 | * @access public |
||
338 | * @static static method |
||
339 | * @param string $userId |
||
340 | * @param string $sessionId |
||
341 | * @return string |
||
342 | * |
||
343 | */ |
||
344 | View Code Duplication | private static function updateSessionId($userId, $sessionId = null){ |
|
353 | |||
354 | /** |
||
355 | * Remove the session |
||
356 | * Delete session completely from the browser cookies and destroy it's file on the server |
||
357 | * |
||
358 | * @access public |
||
359 | * @static static method |
||
360 | */ |
||
361 | public static function remove(){ |
||
386 | |||
387 | } |
||
388 |
You can fix this by adding a namespace to your class:
When choosing a vendor namespace, try to pick something that is not too generic to avoid conflicts with other libraries.