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 Writing_On_GitHub_Post 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.
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 Writing_On_GitHub_Post, and based on these observations, apply Extract Interface, too.
1 | <?php |
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10 | class Writing_On_GitHub_Post { |
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11 | |||
12 | /** |
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13 | * Api object |
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14 | * |
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15 | * @var Writing_On_GitHub_Api |
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16 | */ |
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17 | public $api; |
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18 | |||
19 | /** |
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20 | * Post ID |
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21 | * @var integer |
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22 | */ |
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23 | public $id = 0; |
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24 | |||
25 | /** |
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26 | * Blob object |
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27 | * @var Writing_On_GitHub_Blob |
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28 | */ |
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29 | public $blob; |
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30 | |||
31 | /** |
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32 | * Post object |
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33 | * @var WP_Post |
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34 | */ |
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35 | public $post; |
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36 | |||
37 | /** |
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38 | * Post args. |
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39 | * |
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40 | * @var array |
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41 | */ |
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42 | protected $args; |
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43 | |||
44 | /** |
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45 | * Post meta. |
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46 | * |
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47 | * @var array |
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48 | */ |
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49 | protected $meta; |
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50 | |||
51 | /** |
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52 | * Whether the post has been saved. |
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53 | * |
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54 | * @var bool |
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55 | */ |
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56 | protected $new = true; |
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57 | |||
58 | |||
59 | protected $old_github_path; |
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60 | |||
61 | /** |
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62 | * Instantiates a new Post object |
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63 | * |
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64 | * @param int|array $id_or_args Either a post ID or an array of arguments. |
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65 | * @param Writing_On_GitHub_Api $api API object. |
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66 | * |
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67 | * @todo remove database operations from this method |
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68 | */ |
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69 | public function __construct( $id_or_args, Writing_On_GitHub_Api $api ) { |
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93 | |||
94 | public function id() { |
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97 | |||
98 | /** |
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99 | * Returns the post type |
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100 | */ |
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101 | public function type() { |
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104 | |||
105 | /** |
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106 | * Returns the post type |
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107 | */ |
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108 | public function status() { |
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111 | |||
112 | /** |
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113 | * Returns the post name |
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114 | */ |
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115 | public function name() { |
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118 | |||
119 | /** |
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120 | * Returns true if the post has a password |
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121 | * @return bool |
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122 | */ |
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123 | public function has_password() { |
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126 | |||
127 | /** |
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128 | * Combines the 2 content parts for GitHub |
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129 | */ |
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130 | public function github_content() { |
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142 | |||
143 | /** |
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144 | * The post's YAML frontmatter |
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145 | * |
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146 | * Returns String the YAML frontmatter, ready to be written to the file |
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147 | */ |
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148 | public function front_matter() { |
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151 | |||
152 | /** |
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153 | * Returns the post_content |
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154 | * |
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155 | * Markdownify's the content if applicable |
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156 | */ |
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157 | public function post_content() { |
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170 | |||
171 | public function old_github_path() { |
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174 | |||
175 | public function set_old_github_path( $path ) { |
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179 | |||
180 | |||
181 | /** |
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182 | * Retrieves or calculates the proper GitHub path for a given post |
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183 | * |
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184 | * Returns (string) the path relative to repo root |
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185 | */ |
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186 | public function github_path() { |
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191 | |||
192 | /** |
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193 | * Get GitHub directory based on post |
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194 | * |
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195 | * @return string |
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196 | */ |
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197 | public function github_directory() { |
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229 | |||
230 | /** |
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231 | * Build GitHub filename based on post |
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232 | */ |
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233 | public function github_filename() { |
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242 | |||
243 | /** |
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244 | * Returns a post slug we can use in the GitHub filename |
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245 | * |
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246 | * @return string |
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247 | */ |
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248 | protected function get_name() { |
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255 | |||
256 | /** |
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257 | * is put on github |
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258 | * @return boolean |
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259 | */ |
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260 | public function is_on_github() { |
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268 | |||
269 | /** |
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270 | * Returns the URL for the post on GitHub. |
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271 | * |
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272 | * @return string |
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273 | */ |
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274 | View Code Duplication | public function github_view_url() { |
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281 | |||
282 | /** |
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283 | * Returns the URL for the post on GitHub. |
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284 | * |
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285 | * @return string |
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286 | */ |
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287 | View Code Duplication | public function github_edit_url() { |
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294 | |||
295 | /** |
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296 | * Retrieve post type directory from blob path. |
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297 | * |
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298 | * @param string $path Path string. |
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299 | * |
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300 | * @return string |
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301 | */ |
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302 | public function get_directory_from_path( $path ) { |
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308 | |||
309 | /** |
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310 | * Determines the last author to modify the post |
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311 | * |
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312 | * Returns Array an array containing the author name and email |
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313 | */ |
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314 | View Code Duplication | public function last_modified_author() { |
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325 | |||
326 | /** |
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327 | * The post's sha |
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328 | * Cached as post meta, or will make a live call if need be |
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329 | * |
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330 | * Returns String the sha1 hash |
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331 | */ |
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332 | public function sha() { |
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355 | |||
356 | /** |
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357 | * Save the sha to post |
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358 | * |
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359 | * @param string $sha |
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360 | */ |
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361 | public function set_sha( $sha ) { |
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364 | |||
365 | /** |
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366 | * The post's metadata |
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367 | * |
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368 | * Returns Array the post's metadata |
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369 | */ |
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370 | public function meta() { |
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407 | |||
408 | /** |
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409 | * Returns whether the Post has been saved in the DB yet. |
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410 | * |
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411 | * @return bool |
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412 | */ |
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413 | public function is_new() { |
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416 | |||
417 | /** |
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418 | * Sets the Post's meta. |
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419 | * |
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420 | * @param array $meta |
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421 | */ |
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422 | public function set_meta( $meta ) { |
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425 | |||
426 | /** |
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427 | * Returns the Post's arguments. |
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428 | * |
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429 | * @return array |
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430 | */ |
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431 | public function get_args() { |
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434 | |||
435 | /** |
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436 | * Returns the Post's meta. |
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437 | * |
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438 | * @return array |
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439 | */ |
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440 | public function get_meta() { |
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443 | |||
444 | /** |
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445 | * Get the blob |
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446 | * @return Writing_On_GitHub_Blob |
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447 | */ |
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448 | public function get_blob() { |
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451 | |||
452 | /** |
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453 | * Set the blob |
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454 | * @param Writing_On_GitHub_Blob $blob |
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455 | */ |
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456 | public function set_blob( Writing_On_GitHub_Blob $blob ) { |
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459 | |||
460 | /** |
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461 | * Sets the Post's WP_Post object. |
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462 | * |
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463 | * @param WP_Post $post |
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464 | * |
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465 | * @return $this |
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466 | */ |
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467 | public function set_post( WP_Post $post ) { |
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473 | |||
474 | /** |
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475 | * Transforms the Post into a Blob. |
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476 | * |
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477 | * @return Writing_On_GitHub_Blob |
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478 | */ |
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479 | public function to_blob() { |
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488 | } |
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489 |
Our type inference engine in quite powerful, but sometimes the code does not provide enough clues to go by. In these cases we request you to add a
@return
annotation as described here.