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 BlogController 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 BlogController, and based on these observations, apply Extract Interface, too.
1 | <?php |
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16 | class BlogController extends PageController |
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17 | { |
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18 | /** |
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19 | * @var array |
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20 | */ |
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21 | private static $allowed_actions = array( |
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22 | 'archive', |
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23 | 'tag', |
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24 | 'category', |
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25 | 'rss', |
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26 | 'profile' |
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27 | ); |
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28 | |||
29 | /** |
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30 | * @var array |
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31 | */ |
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32 | private static $url_handlers = array( |
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33 | 'tag/$Tag!/$Rss' => 'tag', |
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34 | 'category/$Category!/$Rss' => 'category', |
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35 | 'archive/$Year!/$Month/$Day' => 'archive', |
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36 | 'profile/$URLSegment!' => 'profile' |
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37 | ); |
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38 | |||
39 | /** |
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40 | * @var array |
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41 | */ |
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42 | private static $casting = array( |
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43 | 'MetaTitle' => 'Text', |
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44 | 'FilterDescription' => 'Text' |
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45 | ); |
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46 | |||
47 | /** |
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48 | * The current Blog Post DataList query. |
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49 | * |
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50 | * @var DataList |
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51 | */ |
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52 | protected $blogPosts; |
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53 | |||
54 | /** |
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55 | * @return string |
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56 | */ |
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57 | public function index() |
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68 | |||
69 | /** |
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70 | * Renders a Blog Member's profile. |
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71 | * |
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72 | * @return HTTPResponse |
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73 | */ |
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74 | public function profile() |
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86 | |||
87 | /** |
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88 | * Get the Member associated with the current URL segment. |
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89 | * |
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90 | * @return null|Member |
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91 | */ |
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92 | public function getCurrentProfile() |
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104 | |||
105 | /** |
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106 | * Get posts related to the current Member profile. |
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107 | * |
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108 | * @return null|DataList |
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109 | */ |
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110 | public function getCurrentProfilePosts() |
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120 | |||
121 | /** |
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122 | * Renders an archive for a specified date. This can be by year or year/month. |
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123 | * |
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124 | * @return null|HTTPResponse |
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125 | */ |
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126 | public function archive() |
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155 | |||
156 | /** |
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157 | * Fetches the archive year from the url. |
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158 | * |
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159 | * @return int |
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160 | */ |
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161 | public function getArchiveYear() |
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173 | |||
174 | /** |
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175 | * Fetches the archive money from the url. |
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176 | * |
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177 | * @return null|int |
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178 | */ |
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179 | public function getArchiveMonth() |
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193 | |||
194 | /** |
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195 | * Fetches the archive day from the url. |
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196 | * |
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197 | * @return null|int |
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198 | */ |
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199 | public function getArchiveDay() |
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211 | |||
212 | /** |
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213 | * Renders the blog posts for a given tag. |
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214 | * |
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215 | * @return null|HTTPResponse |
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216 | */ |
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217 | View Code Duplication | public function tag() |
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235 | |||
236 | /** |
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237 | * Tag Getter for use in templates. |
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238 | * |
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239 | * @return null|BlogTag |
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240 | */ |
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241 | View Code Duplication | public function getCurrentTag() |
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255 | |||
256 | /** |
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257 | * Renders the blog posts for a given category. |
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258 | * |
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259 | * @return null|HTTPResponse |
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260 | */ |
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261 | View Code Duplication | public function category() |
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279 | |||
280 | /** |
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281 | * Category Getter for use in templates. |
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282 | * |
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283 | * @return null|BlogCategory |
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284 | */ |
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285 | View Code Duplication | public function getCurrentCategory() |
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299 | |||
300 | /** |
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301 | * Get the meta title for the current action. |
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302 | * |
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303 | * @return string |
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304 | */ |
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305 | public function getMetaTitle() |
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318 | |||
319 | /** |
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320 | * Returns a description of the current filter. |
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321 | * |
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322 | * @return string |
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323 | */ |
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324 | public function getFilterDescription() |
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404 | |||
405 | /** |
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406 | * Returns a list of paginated blog posts based on the BlogPost dataList. |
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407 | * |
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408 | * @return PaginatedList |
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409 | */ |
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410 | public function PaginatedList() |
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431 | |||
432 | /** |
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433 | * Displays an RSS feed of blog posts. |
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434 | * |
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435 | * @return string |
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436 | */ |
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437 | public function rss() |
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448 | |||
449 | /** |
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450 | * Returns the current archive date. |
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451 | * |
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452 | * @return null|Date |
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453 | */ |
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454 | public function getArchiveDate() |
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478 | |||
479 | /** |
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480 | * Returns a link to the RSS feed. |
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481 | * |
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482 | * @return string |
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483 | */ |
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484 | public function getRSSLink() |
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488 | |||
489 | /** |
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490 | * Displays an RSS feed of the given blog posts. |
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491 | * |
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492 | * @param DataList $blogPosts |
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493 | * @param string $link |
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494 | * |
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495 | * @return string |
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496 | */ |
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497 | protected function rssFeed($blogPosts, $link) |
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505 | |||
506 | /** |
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507 | * Returns true if the $Rss sub-action for categories/tags has been set to "rss" |
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508 | * |
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509 | * @return bool |
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510 | */ |
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511 | protected function isRSS() |
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516 | } |
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517 |
This check marks private properties in classes that are never used. Those properties can be removed.