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 BlogPost 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 BlogPost, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 40 | class BlogPost extends Page |
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| 41 | { |
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| 42 | /** |
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| 43 | * Same as above, but for list of users that can be |
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| 44 | * given credit in the author field for blog posts |
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| 45 | * @var string|bool false or group code |
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| 46 | */ |
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| 47 | private static $restrict_authors_to_group = false; |
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| 48 | |||
| 49 | /** |
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| 50 | * {@inheritDoc} |
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| 51 | * @var string |
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| 52 | */ |
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| 53 | private static $table_name = 'BlogPost'; |
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| 54 | |||
| 55 | /** |
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| 56 | * @var array |
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| 57 | */ |
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| 58 | private static $db = [ |
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| 59 | 'PublishDate' => 'Datetime', |
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| 60 | 'AuthorNames' => 'Varchar(1024)', |
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| 61 | 'Summary' => 'HTMLText' |
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| 62 | ]; |
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| 63 | |||
| 64 | /** |
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| 65 | * @var array |
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| 66 | */ |
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| 67 | private static $has_one = [ |
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| 68 | 'FeaturedImage' => Image::class |
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| 69 | ]; |
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| 70 | |||
| 71 | /** |
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| 72 | * @var array |
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| 73 | */ |
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| 74 | private static $owns = [ |
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| 75 | 'FeaturedImage', |
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| 76 | ]; |
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| 77 | |||
| 78 | /** |
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| 79 | * @var array |
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| 80 | */ |
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| 81 | private static $many_many = [ |
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| 82 | 'Categories' => BlogCategory::class, |
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| 83 | 'Tags' => BlogTag::class, |
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| 84 | 'Authors' => Member::class |
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| 85 | ]; |
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| 86 | |||
| 87 | /** |
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| 88 | * @var array |
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| 89 | */ |
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| 90 | private static $defaults = [ |
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| 91 | 'ShowInMenus' => false, |
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| 92 | 'InheritSideBar' => true, |
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| 93 | 'ProvideComments' => true |
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| 94 | ]; |
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| 95 | |||
| 96 | /** |
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| 97 | * @var array |
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| 98 | */ |
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| 99 | private static $extensions = [ |
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| 100 | BlogPostFilter::class |
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| 101 | ]; |
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| 102 | |||
| 103 | /** |
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| 104 | * @var array |
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| 105 | */ |
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| 106 | private static $searchable_fields = [ |
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| 107 | 'Title' |
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| 108 | ]; |
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| 109 | |||
| 110 | /** |
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| 111 | * @var array |
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| 112 | */ |
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| 113 | private static $summary_fields = [ |
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| 114 | 'Title' |
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| 115 | ]; |
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| 116 | |||
| 117 | /** |
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| 118 | * @var array |
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| 119 | */ |
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| 120 | private static $casting = [ |
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| 121 | 'Excerpt' => 'HTMLText', |
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| 122 | 'Date' => 'DBDatetime' |
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| 123 | ]; |
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| 124 | |||
| 125 | /** |
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| 126 | * @var array |
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| 127 | */ |
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| 128 | private static $allowed_children = []; |
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| 129 | |||
| 130 | /** |
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| 131 | * The default sorting lists BlogPosts with an empty PublishDate at the top. |
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| 132 | * |
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| 133 | * @var string |
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| 134 | */ |
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| 135 | private static $default_sort = '"PublishDate" IS NULL DESC, "PublishDate" DESC'; |
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| 136 | |||
| 137 | /** |
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| 138 | * @var bool |
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| 139 | */ |
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| 140 | private static $can_be_root = false; |
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| 141 | |||
| 142 | /** |
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| 143 | * This will display or hide the current class from the SiteTree. This variable can be |
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| 144 | * configured using YAML. |
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| 145 | * |
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| 146 | * @var bool |
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| 147 | */ |
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| 148 | private static $show_in_sitetree = false; |
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| 149 | |||
| 150 | /** |
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| 151 | * This helps estimate how long an article will take to read, if your target audience |
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| 152 | * is elderly then you should lower this value. See {@link getMinutesToRead()} |
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| 153 | * |
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| 154 | * @var int |
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| 155 | */ |
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| 156 | private static $minutes_to_read_wpm = 200; |
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| 157 | |||
| 158 | /** |
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| 159 | * Determine the role of the given member. |
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| 160 | * |
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| 161 | * Call be called via template to determine the current user. |
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| 162 | * |
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| 163 | * @example "Hello $RoleOf($CurrentMember.ID)" |
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| 164 | * |
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| 165 | * @param null|int|Member $member |
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| 166 | * |
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| 167 | * @return null|string |
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| 168 | */ |
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| 169 | public function RoleOf($member = null) |
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| 189 | |||
| 190 | /** |
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| 191 | * Determine if the given member is an author of this post. |
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| 192 | * |
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| 193 | * @param null|Member $member |
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| 194 | * |
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| 195 | * @return bool |
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| 196 | */ |
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| 197 | View Code Duplication | public function isAuthor($member = null) |
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| 211 | |||
| 212 | /** |
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| 213 | * {@inheritdoc} |
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| 214 | */ |
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| 215 | public function getCMSFields() |
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| 341 | |||
| 342 | /** |
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| 343 | * Gets the list of author candidates to be assigned as authors of this blog post. |
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| 344 | * |
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| 345 | * @return SS_List |
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| 346 | */ |
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| 347 | public function getCandidateAuthors() |
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| 357 | |||
| 358 | /** |
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| 359 | * Determine if this user can edit the authors list. |
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| 360 | * |
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| 361 | * @param null|int|Member $member |
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| 362 | * |
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| 363 | * @return bool |
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| 364 | */ |
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| 365 | public function canEditAuthors($member = null) |
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| 389 | |||
| 390 | /** |
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| 391 | * @param null|int|Member $member |
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| 392 | * |
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| 393 | * @return null|Member |
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| 394 | */ |
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| 395 | View Code Duplication | protected function getMember($member = null) |
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| 407 | |||
| 408 | /** |
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| 409 | * Determine whether user can create new categories. |
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| 410 | * |
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| 411 | * @param null|int|Member $member |
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| 412 | * |
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| 413 | * @return bool |
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| 414 | */ |
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| 415 | View Code Duplication | public function canCreateCategories($member = null) |
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| 431 | |||
| 432 | /** |
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| 433 | * Determine whether user can create new tags. |
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| 434 | * |
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| 435 | * @param null|int|Member $member |
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| 436 | * |
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| 437 | * @return bool |
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| 438 | */ |
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| 439 | View Code Duplication | public function canCreateTags($member = null) |
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| 459 | |||
| 460 | /** |
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| 461 | * {@inheritdoc} |
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| 462 | * |
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| 463 | * Update the PublishDate to now if the BlogPost would otherwise be published without a date. |
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| 464 | */ |
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| 465 | public function onBeforePublish() |
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| 477 | |||
| 478 | /** |
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| 479 | * {@inheritdoc} |
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| 480 | * |
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| 481 | * Sets blog relationship on all categories and tags assigned to this post. |
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| 482 | */ |
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| 483 | public function onAfterWrite() |
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| 503 | |||
| 504 | /** |
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| 505 | * {@inheritdoc} |
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| 506 | */ |
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| 507 | public function canView($member = null) |
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| 534 | |||
| 535 | /** |
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| 536 | * {@inheritdoc} |
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| 537 | */ |
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| 538 | public function canPublish($member = null) |
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| 570 | |||
| 571 | /** |
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| 572 | * {@inheritdoc} |
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| 573 | */ |
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| 574 | public function canEdit($member = null) |
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| 598 | |||
| 599 | /** |
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| 600 | * Returns the post excerpt. |
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| 601 | * |
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| 602 | * @param int $wordsToDisplay |
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| 603 | * |
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| 604 | * @return string |
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| 605 | */ |
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| 606 | public function Excerpt($wordsToDisplay = 30) |
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| 613 | |||
| 614 | /** |
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| 615 | * Returns a monthly archive link for the current blog post. |
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| 616 | * |
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| 617 | * @param string $type |
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| 618 | * |
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| 619 | * @return string |
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| 620 | */ |
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| 621 | public function getMonthlyArchiveLink($type = 'day') |
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| 643 | |||
| 644 | /** |
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| 645 | * Returns a yearly archive link for the current blog post. |
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| 646 | * |
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| 647 | * @return string |
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| 648 | */ |
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| 649 | public function getYearlyArchiveLink() |
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| 658 | |||
| 659 | /** |
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| 660 | * Resolves static and dynamic authors linked to this post. |
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| 661 | * |
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| 662 | * @return ArrayList |
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| 663 | */ |
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| 664 | public function getCredits() |
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| 673 | |||
| 674 | /** |
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| 675 | * Resolves dynamic authors linked to this post. |
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| 676 | * |
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| 677 | * @return ArrayList |
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| 678 | */ |
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| 679 | protected function getDynamicCredits() |
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| 705 | |||
| 706 | /** |
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| 707 | * Resolves static authors linked to this post. |
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| 708 | * |
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| 709 | * @return ArrayList |
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| 710 | */ |
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| 711 | protected function getStaticCredits() |
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| 727 | |||
| 728 | /** |
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| 729 | * Checks to see if User Profiles has been disabled via config |
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| 730 | * |
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| 731 | * @return bool |
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| 732 | */ |
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| 733 | public function getProfilesDisabled() |
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| 737 | |||
| 738 | /** |
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| 739 | * Sets the label for BlogPost.Title to 'Post Title' (Rather than 'Page name'). |
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| 740 | * |
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| 741 | * @param bool $includeRelations |
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| 742 | * |
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| 743 | * @return array |
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| 744 | */ |
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| 745 | public function fieldLabels($includeRelations = true) |
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| 753 | |||
| 754 | /** |
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| 755 | * Proxy method for displaying the publish date in rss feeds. |
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| 756 | * @see https://github.com/silverstripe/silverstripe-blog/issues/394 |
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| 757 | * |
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| 758 | * @return string|null |
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| 759 | */ |
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| 760 | public function getDate() |
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| 767 | |||
| 768 | /** |
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| 769 | * Provides a rough estimate of how long this post will take to read based on wikipedias answer to "How fast can a |
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| 770 | * human read" of 200wpm. Source https://en.wikipedia.org/wiki/Speed_reading |
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| 771 | * |
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| 772 | * @param null|integer $wpm |
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| 773 | * |
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| 774 | * @return string |
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| 775 | */ |
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| 776 | public function MinutesToRead($wpm = null) |
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| 792 | |||
| 793 | /** |
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| 794 | * {@inheritdoc} |
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| 795 | */ |
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| 796 | protected function onBeforeWrite() |
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| 804 | } |
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| 805 |
This check marks private properties in classes that are never used. Those properties can be removed.