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 $nodeProps; |
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| 46 | |||
| 47 | 63 | public function __construct($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 $component |
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| 62 | */ |
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| 63 | 63 | public function select($component) { |
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| 64 | 63 | $previous = $this->currentName; |
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| 65 | 63 | $this->currentName = $component; |
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| 66 | |||
| 67 | 63 | if (!array_key_exists($component, $this->buffers)) { |
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| 68 | 63 | $this->buffers[$component] = $buffer = new ComponentBuffer($this->defaults); |
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| 69 | } |
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| 70 | |||
| 71 | 63 | $this->current =& $this->buffers[$component]; |
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| 72 | |||
| 73 | 63 | return $previous; |
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| 74 | } |
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| 75 | |||
| 76 | 57 | public function echoLiteral($value) { |
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| 79 | |||
| 80 | 43 | public function echoCode($php) { |
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| 83 | |||
| 84 | 63 | public function appendCode($php) { |
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| 87 | |||
| 88 | 63 | 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 | 63 | public function pushScope(array $vars) { |
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| 103 | |||
| 104 | 57 | public function popScope() { |
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| 107 | |||
| 108 | 55 | public function getScopeVariables() { |
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| 111 | |||
| 112 | 57 | public function flush() { |
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| 113 | 57 | switch ($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 $this |
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| 189 | */ |
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| 190 | 63 | public function setBasename($basename) { |
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| 194 | |||
| 195 | 63 | public function getNodeProp(\DOMNode $node, $name, $default = null) { |
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| 201 | |||
| 202 | 23 | public function setNodeProp(\DOMNode $node = null, $name, $value) { |
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| 203 | 23 | if ($node === null) { |
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| 204 | 19 | return $this; |
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| 205 | } |
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| 206 | |||
| 207 | 4 | if (!$this->nodeProps->contains($node)) { |
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| 208 | 4 | $this->nodeProps->attach($node, [$name => $value]); |
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| 209 | } |
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| 210 | |||
| 211 | 4 | $this->nodeProps[$node] = [$name => $value] + $this->nodeProps[$node]; |
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| 212 | 4 | 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 | 6 | public function createCompilerException(\DOMNode $node, \Exception $ex, array $context = []) { |
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| 240 | $result = $context + [ |
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| 241 | 6 | 'path' => $this->getPath(), |
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| 242 | 6 | 'source' => '', |
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| 243 | 'sourcePosition' => null, |
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| 244 | 6 | 'line' => $node->getLineNo(), |
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| 245 | 'lines' => [] |
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| 246 | ]; |
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| 247 | 6 | $message = $ex->getMessage(); |
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| 248 | |||
| 249 | 6 | if ($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'] = $position; |
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| 254 | } |
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| 255 | 3 | } elseif (empty($result['source'])) { |
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| 256 | 3 | 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 | 6 | if (!empty($this->source)) { |
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| 262 | 6 | $allLines = explode("\n", $this->source); |
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| 263 | |||
| 264 | 6 | $lines = []; |
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| 265 | 6 | $line = $result['line']; |
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| 266 | 6 | for ($i = max(0, $line - 4); $i < $line + 3; $i++) { |
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| 267 | 6 | if (isset($allLines[$i])) { |
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| 268 | 6 | $lines[$i + 1] = $allLines[$i]; |
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| 269 | } |
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| 270 | } |
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| 271 | |||
| 272 | 6 | $result['lines'] = $lines; |
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| 273 | } |
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| 274 | |||
| 275 | 6 | return new CompileException($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 $this |
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| 300 | */ |
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| 301 | 63 | public function setSource($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 | 6 | 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 $this |
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| 320 | */ |
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| 321 | 63 | public function setPath($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.