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 Comment 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 Comment, and based on these observations, apply Extract Interface, too.
1 | <?php |
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13 | class Comment extends Basis { |
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14 | |||
15 | /** |
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16 | * Comment ID. |
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17 | * |
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18 | * @var int |
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19 | */ |
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20 | public $comment_ID; |
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21 | |||
22 | /** |
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23 | * Comment post ID. |
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24 | * |
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25 | * @var int |
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26 | */ |
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27 | public $comment_post_ID; |
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28 | |||
29 | /** |
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30 | * Comment Author name. |
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31 | * |
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32 | * @var string |
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33 | */ |
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34 | public $comment_author; |
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35 | |||
36 | /** |
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37 | * Comment author email. |
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38 | * |
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39 | * @var string |
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40 | */ |
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41 | public $comment_author_email; |
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42 | |||
43 | /** |
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44 | * Comment author link. |
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45 | * |
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46 | * @var string |
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47 | */ |
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48 | public $comment_author_url; |
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49 | |||
50 | /** |
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51 | * Comment. |
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52 | * |
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53 | * @var string |
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54 | */ |
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55 | public $comment_content; |
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56 | |||
57 | /** |
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58 | * Comment approved. |
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59 | * |
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60 | * @var boolean |
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61 | */ |
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62 | public $comment_approved; |
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63 | |||
64 | /** |
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65 | * Comment date. |
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66 | * |
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67 | * @var string |
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68 | */ |
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69 | public $comment_date; |
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70 | |||
71 | /** |
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72 | * User ID. |
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73 | * |
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74 | * @var int |
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75 | */ |
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76 | public $user_id; |
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77 | |||
78 | /** |
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79 | * Comment nested level. |
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80 | * |
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81 | * @var int |
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82 | */ |
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83 | public $level; |
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84 | |||
85 | /** |
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86 | * Comment Parent ID. |
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87 | * |
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88 | * @var int |
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89 | */ |
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90 | public $comment_parent; |
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91 | |||
92 | /** |
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93 | * Child comments. |
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94 | * |
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95 | * @var array |
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96 | */ |
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97 | protected $children = array(); |
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98 | |||
99 | /** |
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100 | * Checks if provided arg is instance of WP_Comment and init it. |
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101 | * |
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102 | * @param \WP_Comment $item WP_Comment object. |
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103 | */ |
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104 | public function __construct( $item ) { |
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109 | |||
110 | /** |
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111 | * Returns User object of comment author. |
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112 | * |
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113 | * @return \Classy\Models\User |
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114 | */ |
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115 | public function author() { |
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129 | |||
130 | /** |
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131 | * Returns comment content. |
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132 | * |
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133 | * @return string |
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134 | */ |
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135 | public function content() { |
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138 | |||
139 | /** |
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140 | * Return true if comment is approved. |
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141 | * |
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142 | * @return boolean |
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143 | */ |
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144 | public function approved() { |
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147 | |||
148 | /** |
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149 | * Returns comment date. |
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150 | * |
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151 | * @param string $date_format Optional. PHP date format defaults to the date_format option if not specified. |
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152 | * |
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153 | * @return string |
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154 | */ |
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155 | public function date( $date_format = '' ) { |
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161 | |||
162 | /** |
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163 | * Returns true if comment has parent. |
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164 | * |
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165 | * @return boolean |
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166 | */ |
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167 | public function has_parent() { |
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170 | |||
171 | /** |
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172 | * Shows gravatar. |
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173 | * |
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174 | * @param integer $size avatar image size |
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175 | * @param string $default |
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176 | * |
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177 | * @return string |
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178 | */ |
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179 | public function avatar( $size = 92, $default = '' ) { |
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204 | |||
205 | /** |
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206 | * Returns email address that will be used for generating avatar. |
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207 | * |
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208 | * @return string |
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209 | */ |
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210 | protected function get_avatar_email() { |
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222 | |||
223 | /** |
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224 | * Returns default avatar url. |
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225 | * |
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226 | * @param string $default |
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227 | * @param string $email |
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228 | * @param int $size |
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229 | * @param string $host |
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230 | * @return string |
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231 | */ |
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232 | protected function get_default_avatar( $default, $email, $size, $host ) { |
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261 | |||
262 | /** |
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263 | * Returns gravatar host. |
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264 | * |
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265 | * @param string $email_hash |
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266 | * @return string |
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267 | */ |
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268 | protected function get_avatar_host( $email_hash ) { |
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282 | |||
283 | /** |
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284 | * Returns avatar url |
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285 | * |
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286 | * @param string $default |
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287 | * @param string $host |
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288 | * @param string $email_hash |
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289 | * @param int $size |
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290 | * @return string |
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291 | */ |
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292 | protected function get_avatar_url( $default, $host, $email_hash, $size ) { |
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302 | |||
303 | /** |
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304 | * Adds child to current Comment |
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305 | * |
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306 | * @param Comment $comment |
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307 | */ |
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308 | public function add_child( $comment ) { |
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316 | |||
317 | /** |
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318 | * Updates children nesting level param |
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319 | * |
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320 | * @return boolean |
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321 | */ |
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322 | View Code Duplication | protected function update_child_levels() { |
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334 | } |
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335 |
This check marks access to variables or properties that have not been declared yet. While PHP has no explicit notion of declaring a variable, accessing it before a value is assigned to it is most likely a bug.