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 Blog 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 Blog, and based on these observations, apply Extract Interface, too.
1 | <?php |
||
44 | class Blog extends Page implements PermissionProvider |
||
45 | { |
||
46 | /** |
||
47 | * Permission for user management. |
||
48 | * |
||
49 | * @var string |
||
50 | */ |
||
51 | const MANAGE_USERS = 'BLOG_MANAGE_USERS'; |
||
52 | |||
53 | /** |
||
54 | * If true, users assigned as editor, writer, or contributor will be automatically granted |
||
55 | * CMS_ACCESS_CMSMain permission. If false, only users with this permission already may be |
||
56 | * assigned. |
||
57 | * |
||
58 | * @config |
||
59 | * |
||
60 | * @var boolean |
||
61 | */ |
||
62 | private static $grant_user_access = true; |
||
|
|||
63 | |||
64 | /** |
||
65 | * Permission to either require, or grant to users assigned to work on this blog. |
||
66 | * |
||
67 | * @config |
||
68 | * |
||
69 | * @var string |
||
70 | */ |
||
71 | private static $grant_user_permission = 'CMS_ACCESS_CMSMain'; |
||
72 | |||
73 | /** |
||
74 | * Group code to assign newly granted users to. |
||
75 | * |
||
76 | * @config |
||
77 | * |
||
78 | * @var string |
||
79 | */ |
||
80 | private static $grant_user_group = 'blog-users'; |
||
81 | |||
82 | /** |
||
83 | * {@inheritDoc} |
||
84 | * @var string |
||
85 | */ |
||
86 | private static $table_name = 'Blog'; |
||
87 | |||
88 | /** |
||
89 | * @var array |
||
90 | */ |
||
91 | private static $db = array( |
||
92 | 'PostsPerPage' => 'Int', |
||
93 | ); |
||
94 | |||
95 | /** |
||
96 | * @var array |
||
97 | */ |
||
98 | private static $has_many = array( |
||
99 | 'Tags' => BlogTag::class, |
||
100 | 'Categories' => BlogCategory::class, |
||
101 | ); |
||
102 | |||
103 | /** |
||
104 | * @var array |
||
105 | */ |
||
106 | private static $many_many = array( |
||
107 | 'Editors' => Member::class, |
||
108 | 'Writers' => Member::class, |
||
109 | 'Contributors' => Member::class, |
||
110 | ); |
||
111 | |||
112 | /** |
||
113 | * @var array |
||
114 | */ |
||
115 | private static $allowed_children = array( |
||
116 | BlogPost::class, |
||
117 | ); |
||
118 | |||
119 | /** |
||
120 | * @var array |
||
121 | */ |
||
122 | private static $extensions = array( |
||
123 | BlogFilter::class, |
||
124 | ); |
||
125 | |||
126 | /** |
||
127 | * @var array |
||
128 | */ |
||
129 | private static $defaults = array( |
||
130 | 'ProvideComments' => false, |
||
131 | 'PostsPerPage' => 10 |
||
132 | ); |
||
133 | |||
134 | /** |
||
135 | * @var string |
||
136 | */ |
||
137 | private static $description = 'Adds a blog to your website.'; |
||
138 | |||
139 | private static $icon = 'blog/images/site-tree-icon.png'; |
||
140 | |||
141 | /** |
||
142 | * {@inheritdoc} |
||
143 | */ |
||
144 | public function getCMSFields() |
||
196 | |||
197 | /** |
||
198 | * {@inheritdoc} |
||
199 | */ |
||
200 | public function canEdit($member = null) |
||
210 | |||
211 | /** |
||
212 | * @param null|int|Member $member |
||
213 | * |
||
214 | * @return null|Member |
||
215 | */ |
||
216 | View Code Duplication | protected function getMember($member = null) |
|
228 | |||
229 | /** |
||
230 | * Check if this member is an editor of the blog. |
||
231 | * |
||
232 | * @param Member $member |
||
233 | * |
||
234 | * @return bool |
||
235 | */ |
||
236 | public function isEditor($member) |
||
243 | |||
244 | /** |
||
245 | * Determine if the given member belongs to the given relation. |
||
246 | * |
||
247 | * @param Member $member |
||
248 | * @param DataList $relation |
||
249 | * |
||
250 | * @return bool |
||
251 | */ |
||
252 | View Code Duplication | protected function isMemberOf($member, $relation) |
|
264 | |||
265 | /** |
||
266 | * Determine the role of the given member. |
||
267 | * |
||
268 | * Call be called via template to determine the current user. |
||
269 | * |
||
270 | * @example "Hello $RoleOf($CurrentMember.ID)" |
||
271 | * |
||
272 | * @param int|Member $member |
||
273 | * |
||
274 | * @return null|string |
||
275 | */ |
||
276 | public function RoleOf($member) |
||
300 | |||
301 | /** |
||
302 | * Check if this member is a writer of the blog. |
||
303 | * |
||
304 | * @param Member $member |
||
305 | * |
||
306 | * @return bool |
||
307 | */ |
||
308 | public function isWriter($member) |
||
315 | |||
316 | /** |
||
317 | * Check if this member is a contributor of the blog. |
||
318 | * |
||
319 | * @param Member $member |
||
320 | * |
||
321 | * @return bool |
||
322 | */ |
||
323 | public function isContributor($member) |
||
330 | |||
331 | /** |
||
332 | * {@inheritdoc} |
||
333 | */ |
||
334 | public function canAddChildren($member = null) |
||
344 | |||
345 | /** |
||
346 | * {@inheritdoc} |
||
347 | */ |
||
348 | public function getSettingsFields() |
||
420 | |||
421 | /** |
||
422 | * Gets the list of user candidates to be assigned to assist with this blog. |
||
423 | * |
||
424 | * @return SS_List |
||
425 | */ |
||
426 | protected function getCandidateUsers() |
||
438 | |||
439 | /** |
||
440 | * Determine if this user can edit the editors list. |
||
441 | * |
||
442 | * @param int|Member $member |
||
443 | * |
||
444 | * @return bool |
||
445 | */ |
||
446 | public function canEditEditors($member = null) |
||
458 | |||
459 | /** |
||
460 | * Determine if this user can edit writers list. |
||
461 | * |
||
462 | * @param int|Member $member |
||
463 | * |
||
464 | * @return boolean |
||
465 | */ |
||
466 | View Code Duplication | public function canEditWriters($member = null) |
|
482 | |||
483 | /** |
||
484 | * Determines if this user can edit the contributors list. |
||
485 | * |
||
486 | * @param int|Member $member |
||
487 | * |
||
488 | * @return boolean |
||
489 | */ |
||
490 | View Code Duplication | public function canEditContributors($member = null) |
|
506 | |||
507 | /** |
||
508 | * Returns BlogPosts for a given date period. |
||
509 | * |
||
510 | * @param int $year |
||
511 | * @param null|int $month |
||
512 | * @param null|int $day |
||
513 | * |
||
514 | * @return DataList |
||
515 | */ |
||
516 | public function getArchivedBlogPosts($year, $month = null, $day = null) |
||
551 | |||
552 | /** |
||
553 | * Return blog posts. |
||
554 | * |
||
555 | * @return DataList of BlogPost objects |
||
556 | */ |
||
557 | public function getBlogPosts() |
||
565 | |||
566 | /** |
||
567 | * Get a link to a Member profile. |
||
568 | * |
||
569 | * @param string $urlSegment |
||
570 | * |
||
571 | * @return string |
||
572 | */ |
||
573 | public function ProfileLink($urlSegment) |
||
583 | |||
584 | /** |
||
585 | * This sets the title for our gridfield. |
||
586 | * |
||
587 | * @return string |
||
588 | */ |
||
589 | public function getLumberjackTitle() |
||
593 | |||
594 | /** |
||
595 | * This overwrites lumberjacks default gridfield config. |
||
596 | * |
||
597 | * @return GridFieldConfig |
||
598 | */ |
||
599 | public function getLumberjackGridFieldConfig() |
||
603 | |||
604 | /** |
||
605 | * {@inheritdoc} |
||
606 | */ |
||
607 | public function providePermissions() |
||
624 | |||
625 | /** |
||
626 | * {@inheritdoc} |
||
627 | */ |
||
628 | protected function onBeforeWrite() |
||
633 | |||
634 | /** |
||
635 | * Assign users as necessary to the blog group. |
||
636 | */ |
||
637 | protected function assignGroup() |
||
656 | |||
657 | /** |
||
658 | * Gets or creates the group used to assign CMS access. |
||
659 | * |
||
660 | * @return Group |
||
661 | */ |
||
662 | protected function getUserGroup() |
||
685 | } |
||
686 |
This check marks private properties in classes that are never used. Those properties can be removed.