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 NodeGenerator 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 NodeGenerator, and based on these observations, apply Extract Interface, too.
1 | <?php |
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20 | final class NodeGenerator |
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21 | { |
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22 | /** |
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23 | * @var PhpGenerator |
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24 | */ |
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25 | private $phpGenerator; |
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26 | |||
27 | /** |
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28 | * @var bool |
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29 | */ |
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30 | private $useQueryBuilderFactory; |
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31 | |||
32 | /** |
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33 | * @param PhpGenerator $phpGenerator |
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34 | * @param bool $useQueryBuilderFactory |
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35 | */ |
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36 | 15 | public function __construct(PhpGenerator $phpGenerator, bool $useQueryBuilderFactory = false) |
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45 | |||
46 | /** |
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47 | * @param $query |
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48 | * |
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49 | * @return string |
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50 | */ |
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51 | 15 | public function generateByJson($query): string |
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68 | |||
69 | /** |
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70 | * @return Expr |
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71 | */ |
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72 | 13 | View Code Duplication | private function createObjectNode(): Expr |
80 | |||
81 | /** |
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82 | * @return Expr |
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83 | */ |
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84 | 4 | View Code Duplication | private function createArrayNode(): Expr |
92 | |||
93 | /** |
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94 | * @param string|float|int|bool|null $value |
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95 | * |
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96 | * @return Expr |
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97 | */ |
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98 | 13 | private function createScalarNode($value): Expr |
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106 | |||
107 | /** |
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108 | * @param string|float|int|bool|null $value |
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109 | * |
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110 | * @return Expr |
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111 | */ |
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112 | 12 | View Code Duplication | private function createScalarNodeDefault($value): Expr |
126 | |||
127 | /** |
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128 | * @param string|float|int|bool|null $value |
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129 | * |
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130 | * @return Expr |
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131 | */ |
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132 | 1 | View Code Duplication | private function createScalarNodeQueryBuilderFactory($value): Expr |
146 | |||
147 | /** |
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148 | * @param array $data |
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149 | * |
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150 | * @return Expr |
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151 | */ |
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152 | 4 | private function appendChildrenToArrayNode(array $data) |
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176 | |||
177 | /** |
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178 | * @param \stdClass $data |
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179 | * |
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180 | * @return Expr |
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181 | */ |
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182 | 13 | private function appendChildrenToObjectNode(\stdClass $data) |
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206 | |||
207 | /** |
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208 | * @param string $code |
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209 | * |
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210 | * @return string |
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211 | */ |
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212 | 14 | private function structureCode(string $code): string |
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229 | |||
230 | /** |
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231 | * @param string $code |
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232 | * |
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233 | * @return array |
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234 | */ |
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235 | 14 | private function getLinesByCode(string $code): array |
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241 | |||
242 | /** |
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243 | * @param string $line |
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244 | * @param string $lastStructuredLine |
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245 | * @param int $position |
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246 | * @param array $structuredLines |
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247 | */ |
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248 | 14 | private function structuredLine(string $line, string $lastStructuredLine, int &$position, array &$structuredLines) |
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280 | } |
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281 |
If you suppress an error, we recommend checking for the error condition explicitly: