Complex classes like Reflection 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 Reflection, and based on these observations, apply Extract Interface, too.
1 | <?php |
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5 | abstract class Reflection implements \Reflector |
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6 | { |
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7 | const IS_STATIC = 1; |
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8 | const IS_ABSTRACT = 2; |
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9 | const IS_FINAL = 4; |
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10 | const IS_IMPLICIT_ABSTRACT = 16; |
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11 | const IS_EXPLICIT_ABSTRACT = 32; |
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12 | const IS_PUBLIC = 256; |
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13 | const IS_PROTECTED = 512; |
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14 | const IS_PRIVATE = 1024; |
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15 | const IS_DEPRECATED = 262144; |
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16 | |||
17 | /** |
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18 | * @type string |
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19 | */ |
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20 | protected $name; |
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21 | |||
22 | /** |
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23 | * @type string |
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24 | */ |
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25 | protected $fileName; |
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26 | |||
27 | /** |
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28 | * @type int |
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29 | */ |
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30 | protected $startLine; |
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31 | |||
32 | /** |
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33 | * @type int |
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34 | */ |
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35 | protected $endLine; |
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36 | |||
37 | /** |
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38 | * Constructs a new Reflection object. |
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39 | * |
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40 | * @param string $name The fully qualified name |
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41 | */ |
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42 | 1101 | public function __construct($name) |
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46 | |||
47 | /** |
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48 | * Gets the fully qualified entity name (with the namespace). |
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49 | * |
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50 | * @return string |
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51 | */ |
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52 | 963 | public function getName() |
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56 | |||
57 | /** |
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58 | * Gets the short name of the entity (without the namespace). |
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59 | * |
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60 | * @return string |
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61 | */ |
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62 | 1101 | public function getShortName() |
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68 | |||
69 | /** |
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70 | * Gets the namespace name. |
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71 | * |
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72 | * @return string |
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73 | */ |
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74 | 12 | public function getNamespaceName() |
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81 | |||
82 | /** |
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83 | * Checks if this entity is defined in a namespace. |
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84 | * |
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85 | * @return bool |
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86 | */ |
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87 | 6 | public function inNamespace() |
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91 | |||
92 | /** |
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93 | * Gets the filename of the file in which the class has been defined. |
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94 | * |
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95 | * @return string |
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96 | */ |
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97 | 1065 | public function getFileName() |
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101 | |||
102 | /** |
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103 | * Get the starting line number. |
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104 | * |
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105 | * @return int |
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106 | */ |
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107 | 6 | public function getStartLine() |
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111 | |||
112 | /** |
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113 | * Get the ending line number. |
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114 | * |
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115 | * @return int |
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116 | */ |
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117 | public function getEndLine() |
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121 | |||
122 | /** |
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123 | * Gets a ReflectionExtension object for the extension which defined the entity. |
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124 | * |
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125 | * @return \ReflectionExtension|null Null for user defined |
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126 | */ |
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127 | public function getExtension() |
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131 | |||
132 | /** |
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133 | * Gets the name of the extension which defined the entity. |
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134 | * |
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135 | * @return string|bool Extension name or false for user defined |
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136 | */ |
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137 | public function getExtensionName() |
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141 | |||
142 | /** |
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143 | * Returns a bitfield of the access modifiers for this class. |
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144 | * |
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145 | * @return int Bitmask of modifier constants |
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146 | */ |
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147 | 12 | public function getModifiers() |
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171 | |||
172 | /** |
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173 | * Returns the string representation of the Reflection object. |
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174 | * |
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175 | * @return string |
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176 | */ |
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177 | public function __toString() |
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181 | |||
182 | /** |
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183 | * Exports a reflected class. |
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184 | * |
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185 | * @param \Reflector $argument The reflection to export. |
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186 | * @param bool $return Setting to true will return the export, otherwise will emitt it. |
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187 | * |
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188 | * @return string|void |
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189 | */ |
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190 | public static function export(\Reflector $argument, $return = false) |
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196 | |||
197 | /** |
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198 | * Gets modifiers names. |
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199 | * |
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200 | * @param int $modifiers |
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201 | * |
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202 | * @return array An array of modifier names |
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203 | */ |
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204 | 6 | public static function getModifierNames($modifiers) |
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239 | |||
240 | /** |
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241 | * Sets the filename of the file in which the class has been defined. |
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242 | * |
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243 | * @internal |
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244 | * |
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245 | * @param string $fileName |
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246 | * |
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247 | * @return self |
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248 | */ |
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249 | 1101 | public function setFilename($fileName) |
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255 | |||
256 | /** |
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257 | * Set the starting line number. |
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258 | * |
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259 | * @internal |
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260 | * |
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261 | * @param int $startLine |
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262 | * |
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263 | * @return self |
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264 | */ |
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265 | 1101 | public function setStartLine($startLine) |
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271 | |||
272 | /** |
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273 | * Set the starting line number. |
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274 | * |
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275 | * @internal |
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276 | * |
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277 | * @param int $endLine |
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278 | * |
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279 | * @return self |
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280 | */ |
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281 | 1101 | public function setEndLine($endLine) |
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287 | } |
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288 |
Let’s take a look at an example:
In the above example, the authenticate() method works fine as long as you just pass instances of MyUser. However, if you now also want to pass a different sub-classes of User which does not have a getDisplayName() method, the code will break.
Available Fixes
Change the type-hint for the parameter:
Add an additional type-check:
Add the method to the parent class: