Complex classes like CompilerBuffer 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 CompilerBuffer, and based on these observations, apply Extract Interface, too.
1 | <?php |
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13 | class CompilerBuffer { |
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14 | const STYLE_JOIN = 'join'; |
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15 | const STYLE_ARRAY = 'array'; |
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16 | |||
17 | /** |
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18 | * @var ComponentBuffer[] |
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19 | */ |
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20 | private $buffers; |
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21 | |||
22 | /** |
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23 | * @var ComponentBuffer |
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24 | */ |
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25 | private $current; |
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26 | |||
27 | private $currentName; |
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28 | |||
29 | private $basename; |
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30 | |||
31 | private $style = self::STYLE_JOIN; |
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32 | |||
33 | private $source; |
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34 | |||
35 | private $path; |
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36 | |||
37 | /** |
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38 | * @var array |
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39 | */ |
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40 | private $defaults; |
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41 | |||
42 | /** |
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43 | * @var \SplObjectStorage |
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44 | */ |
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45 | private $nodeProps; |
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46 | |||
47 | 64 | public function __construct($style = self::STYLE_JOIN, array $defaults = []) { |
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58 | |||
59 | /** |
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60 | * Select a specific component buffer. |
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61 | * @param $component |
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62 | */ |
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63 | 64 | public function select($component) { |
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64 | 64 | $previous = $this->currentName; |
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65 | 64 | $this->currentName = $component; |
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66 | |||
67 | 64 | if (!array_key_exists($component, $this->buffers)) { |
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68 | 64 | $this->buffers[$component] = $buffer = new ComponentBuffer($this->defaults); |
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69 | } |
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70 | |||
71 | 64 | $this->current =& $this->buffers[$component]; |
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72 | |||
73 | 64 | return $previous; |
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74 | } |
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75 | |||
76 | 58 | public function echoLiteral($value) { |
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79 | |||
80 | 44 | public function echoCode($php) { |
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83 | |||
84 | 64 | public function appendCode($php) { |
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87 | |||
88 | 64 | public function indent($add) { |
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91 | |||
92 | 20 | public function depth($add = 1) { |
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95 | |||
96 | 21 | public function depthName($name, $add = 0) { |
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99 | |||
100 | 64 | public function pushScope(array $vars) { |
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103 | |||
104 | 57 | public function popScope() { |
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107 | |||
108 | 56 | public function getScopeVariables() { |
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111 | |||
112 | 57 | public function flush() { |
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113 | 57 | switch ($this->getStyle()) { |
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114 | 57 | case self::STYLE_ARRAY: |
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115 | 11 | return $this->flushArray(); |
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116 | default: |
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117 | 57 | return $this->flushJoin(); |
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118 | } |
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119 | } |
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120 | |||
121 | private function flushJoin() { |
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127 | |||
128 | 11 | private function flushArray() { |
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129 | 11 | $result = []; |
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130 | |||
131 | 11 | foreach ($this->buffers as $name => $buffer) { |
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132 | 11 | $flushed = $buffer->flush(); |
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133 | 11 | if (empty($flushed)) { |
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134 | 9 | continue; |
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135 | } |
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136 | |||
137 | 3 | if ($name === '') { |
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138 | 3 | $result[] = $flushed; |
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139 | } else { |
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140 | 3 | $result[] = var_export($name, true).' => '.$flushed; |
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141 | } |
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142 | } |
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143 | |||
144 | 11 | if (empty($result)) { |
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145 | 9 | return '[]'; |
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146 | } else { |
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147 | 3 | return "[\n".implode(",\n\n", $result)."\n".$this->px().']'; |
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148 | } |
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149 | } |
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150 | |||
151 | 3 | protected function px($add = 0) { |
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154 | |||
155 | /** |
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156 | * Get the style. |
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157 | * |
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158 | * @return string Returns the style. |
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159 | */ |
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160 | 57 | public function getStyle() { |
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163 | |||
164 | /** |
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165 | * Set the style. |
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166 | * |
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167 | * @param string $style One of the **STYLE_*** constants. |
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168 | * @return $this |
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169 | */ |
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170 | public function setStyle($style) { |
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174 | |||
175 | /** |
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176 | * Get the basename. |
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177 | * |
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178 | * @return string Returns the basename. |
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179 | */ |
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180 | public function getBasename() { |
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183 | |||
184 | /** |
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185 | * Set the basename. |
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186 | * |
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187 | * @param string $basename |
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188 | * @return $this |
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189 | */ |
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190 | 64 | public function setBasename($basename) { |
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194 | |||
195 | 64 | public function getNodeProp(\DOMNode $node, $name, $default = null) { |
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201 | |||
202 | 32 | public function setNodeProp(\DOMNode $node = null, $name, $value) { |
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203 | 32 | if ($node === null) { |
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204 | 19 | return $this; |
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205 | } |
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206 | |||
207 | 15 | if (!$this->nodeProps->contains($node)) { |
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208 | 15 | $this->nodeProps->attach($node, [$name => $value]); |
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209 | } |
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210 | |||
211 | 15 | $this->nodeProps[$node] = [$name => $value] + $this->nodeProps[$node]; |
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212 | 15 | return $this; |
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213 | } |
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214 | |||
215 | 11 | public function getIndent() { |
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218 | |||
219 | 11 | public function getDepth() { |
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222 | |||
223 | public function getScope() { |
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226 | |||
227 | 11 | public function getAllScopes() { |
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230 | |||
231 | /** |
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232 | * Create a new **CompileException** with proper context. |
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233 | * |
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234 | * @param \DOMNode $node The node that has the error. |
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235 | * @param \Exception $ex The exception that represents the low-level error. |
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236 | * @param array $context Custom context information for the exception. |
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237 | * @return CompileException Returns a new exception that can be thrown. |
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238 | */ |
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239 | 7 | public function createCompilerException(\DOMNode $node, \Exception $ex, array $context = []) { |
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240 | $result = $context + [ |
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241 | 7 | 'path' => $this->getPath(), |
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242 | 7 | 'source' => '', |
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243 | 'sourcePosition' => null, |
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244 | 7 | 'line' => $node->getLineNo(), |
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245 | 'lines' => [] |
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246 | ]; |
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247 | 7 | $message = $ex->getMessage(); |
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248 | |||
249 | 7 | if ($ex instanceof SyntaxError) { |
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250 | 3 | list($error, $position) = $this->splitSyntaxError($ex); |
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251 | 3 | $result['source'] = $result['source'] ?: ($node instanceof \DOMAttr ? $node->value : $node->nodeValue); |
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252 | 3 | if (!isset($context['sourcePosition'])) { |
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253 | 3 | $result['sourcePosition'] = $position; |
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254 | } |
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255 | 4 | } elseif (empty($result['source'])) { |
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256 | 4 | if ($node instanceof \DOMAttr) { |
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257 | 3 | $result['source'] = $node->name.'="'.$node->value.'"'; |
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258 | } |
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259 | } |
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260 | |||
261 | 7 | if (!empty($this->source)) { |
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262 | 7 | $allLines = explode("\n", $this->source); |
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263 | |||
264 | 7 | $lines = []; |
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265 | 7 | $line = $result['line']; |
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266 | 7 | for ($i = max(0, $line - 4); $i < $line + 3; $i++) { |
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267 | 7 | if (isset($allLines[$i])) { |
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268 | 7 | $lines[$i + 1] = $allLines[$i]; |
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269 | } |
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270 | } |
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271 | |||
272 | 7 | $result['lines'] = $lines; |
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273 | } |
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274 | |||
275 | 7 | return new CompileException($message, $result, $ex); |
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276 | } |
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277 | |||
278 | 3 | private function splitSyntaxError(SyntaxError $ex) { |
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285 | |||
286 | /** |
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287 | * Get the source. |
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288 | * |
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289 | * @return mixed Returns the source. |
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290 | */ |
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291 | public function getSource() { |
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294 | |||
295 | /** |
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296 | * Set the source. |
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297 | * |
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298 | * @param mixed $source |
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299 | * @return $this |
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300 | */ |
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301 | 64 | public function setSource($source) { |
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305 | |||
306 | /** |
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307 | * Get the path. |
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308 | * |
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309 | * @return mixed Returns the path. |
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310 | */ |
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311 | 7 | public function getPath() { |
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314 | |||
315 | /** |
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316 | * Set the path. |
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317 | * |
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318 | * @param mixed $path |
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319 | * @return $this |
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320 | */ |
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321 | 64 | public function setPath($path) { |
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325 | } |
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326 |
This check looks for multiple assignments in successive lines of code. It will report an issue if the operators are not in a straight line.
To visualize
will produce issues in the first and second line, while this second example
will produce no issues.