Complex classes like AbstractNode 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 AbstractNode, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 18 | abstract class AbstractNode |
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| 19 | { |
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| 20 | |||
| 21 | /** |
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| 22 | * Contains the tag name/type |
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| 23 | * |
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| 24 | * @var \PHPHtmlParser\Dom\Tag |
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| 25 | */ |
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| 26 | protected $tag; |
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| 27 | |||
| 28 | /** |
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| 29 | * Contains a list of attributes on this tag. |
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| 30 | * |
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| 31 | * @var array |
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| 32 | */ |
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| 33 | protected $attr = []; |
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| 34 | |||
| 35 | /** |
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| 36 | * Contains the parent Node. |
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| 37 | * |
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| 38 | * @var InnerNode |
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| 39 | */ |
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| 40 | protected $parent = null; |
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| 41 | |||
| 42 | /** |
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| 43 | * The unique id of the class. Given by PHP. |
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| 44 | * |
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| 45 | * @var string |
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| 46 | */ |
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| 47 | protected $id; |
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| 48 | |||
| 49 | /** |
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| 50 | * The encoding class used to encode strings. |
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| 51 | * |
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| 52 | * @var mixed |
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| 53 | */ |
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| 54 | protected $encode; |
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| 55 | |||
| 56 | /** |
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| 57 | * Creates a unique spl hash for this node. |
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| 58 | */ |
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| 59 | public function __construct() |
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| 63 | |||
| 64 | /** |
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| 65 | * Magic get method for attributes and certain methods. |
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| 66 | * |
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| 67 | * @param string $key |
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| 68 | * @return mixed |
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| 69 | */ |
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| 70 | public function __get($key) |
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| 91 | |||
| 92 | /** |
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| 93 | * Attempts to clear out any object references. |
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| 94 | */ |
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| 95 | public function __destruct() |
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| 102 | |||
| 103 | /** |
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| 104 | * Simply calls the outer text method. |
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| 105 | * |
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| 106 | * @return string |
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| 107 | */ |
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| 108 | public function __toString() |
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| 112 | |||
| 113 | /** |
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| 114 | * Returns the id of this object. |
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| 115 | */ |
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| 116 | public function id() |
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| 120 | |||
| 121 | /** |
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| 122 | * Returns the parent of node. |
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| 123 | * |
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| 124 | * @return AbstractNode |
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| 125 | */ |
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| 126 | public function getParent() |
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| 130 | |||
| 131 | /** |
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| 132 | * Sets the parent node. |
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| 133 | * |
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| 134 | * @param InnerNode $parent |
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| 135 | * @return $this |
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| 136 | * @throws CircularException |
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| 137 | */ |
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| 138 | public function setParent(InnerNode $parent) |
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| 160 | |||
| 161 | /** |
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| 162 | * Removes this node and all its children from the |
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| 163 | * DOM tree. |
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| 164 | * |
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| 165 | * @return void |
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| 166 | */ |
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| 167 | public function delete() |
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| 175 | |||
| 176 | /** |
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| 177 | * Sets the encoding class to this node. |
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| 178 | * |
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| 179 | * @param Encode $encode |
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| 180 | * @return void |
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| 181 | */ |
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| 182 | public function propagateEncoding(Encode $encode) |
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| 187 | |||
| 188 | /** |
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| 189 | * Checks if the given node id is an ancestor of |
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| 190 | * the current node. |
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| 191 | * |
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| 192 | * @param int $id |
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| 193 | * @return bool |
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| 194 | */ |
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| 195 | public function isAncestor($id) |
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| 203 | |||
| 204 | /** |
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| 205 | * Attempts to get an ancestor node by the given id. |
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| 206 | * |
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| 207 | * @param int $id |
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| 208 | * @return null|AbstractNode |
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| 209 | */ |
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| 210 | public function getAncestor($id) |
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| 222 | |||
| 223 | /** |
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| 224 | * Attempts to get the next sibling. |
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| 225 | * |
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| 226 | * @return AbstractNode |
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| 227 | * @throws ParentNotFoundException |
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| 228 | */ |
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| 229 | public function nextSibling() |
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| 237 | |||
| 238 | /** |
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| 239 | * Attempts to get the previous sibling |
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| 240 | * |
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| 241 | * @return AbstractNode |
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| 242 | * @throws ParentNotFoundException |
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| 243 | */ |
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| 244 | public function previousSibling() |
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| 252 | |||
| 253 | /** |
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| 254 | * Gets the tag object of this node. |
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| 255 | * |
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| 256 | * @return Tag |
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| 257 | */ |
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| 258 | public function getTag() |
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| 262 | |||
| 263 | /** |
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| 264 | * A wrapper method that simply calls the getAttribute method |
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| 265 | * on the tag of this node. |
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| 266 | * |
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| 267 | * @return array |
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| 268 | */ |
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| 269 | public function getAttributes() |
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| 278 | |||
| 279 | /** |
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| 280 | * A wrapper method that simply calls the getAttribute method |
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| 281 | * on the tag of this node. |
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| 282 | * |
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| 283 | * @param string $key |
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| 284 | * @return mixed |
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| 285 | */ |
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| 286 | public function getAttribute($key) |
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| 295 | |||
| 296 | /** |
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| 297 | * A wrapper method that simply calls the hasAttribute method |
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| 298 | * on the tag of this node. |
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| 299 | * |
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| 300 | * @param string $key |
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| 301 | * @return bool |
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| 302 | */ |
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| 303 | public function hasAttribute($key) |
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| 307 | |||
| 308 | /** |
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| 309 | * A wrapper method that simply calls the setAttribute method |
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| 310 | * on the tag of this node. |
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| 311 | * |
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| 312 | * @param string $key |
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| 313 | * @param string $value |
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| 314 | * @return $this |
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| 315 | */ |
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| 316 | public function setAttribute($key, $value) |
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| 322 | |||
| 323 | /** |
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| 324 | * A wrapper method that simply calls the removeAttribute method |
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| 325 | * on the tag of this node. |
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| 326 | * |
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| 327 | * @param string $key |
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| 328 | * @return void |
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| 329 | */ |
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| 330 | public function removeAttribute($key) |
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| 334 | |||
| 335 | /** |
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| 336 | * A wrapper method that simply calls the removeAllAttributes |
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| 337 | * method on the tag of this node. |
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| 338 | * |
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| 339 | * @return void |
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| 340 | */ |
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| 341 | public function removeAllAttributes() |
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| 345 | |||
| 346 | /** |
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| 347 | * Function to locate a specific ancestor tag in the path to the root. |
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| 348 | * |
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| 349 | * @param string $tag |
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| 350 | * @return AbstractNode |
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| 351 | * @throws ParentNotFoundException |
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| 352 | */ |
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| 353 | public function ancestorByTag($tag) |
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| 368 | |||
| 369 | /** |
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| 370 | * Find elements by css selector |
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| 371 | * |
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| 372 | * @param string $selector |
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| 373 | * @param int $nth |
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| 374 | * @return array|AbstractNode |
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| 375 | */ |
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| 376 | public function find($selector, $nth = null) |
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| 392 | |||
| 393 | /** |
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| 394 | * Gets the inner html of this node. |
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| 395 | * |
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| 396 | * @return string |
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| 397 | */ |
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| 398 | abstract public function innerHtml(); |
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| 399 | |||
| 400 | /** |
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| 401 | * Gets the html of this node, including it's own |
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| 402 | * tag. |
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| 403 | * |
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| 404 | * @return string |
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| 405 | */ |
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| 406 | abstract public function outerHtml(); |
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| 407 | |||
| 408 | /** |
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| 409 | * Gets the text of this node (if there is any text). |
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| 410 | * |
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| 411 | * @return string |
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| 412 | */ |
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| 413 | abstract public function text(); |
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| 414 | |||
| 415 | /** |
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| 416 | * Call this when something in the node tree has changed. Like a child has been added |
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| 417 | * or a parent has been changed. |
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| 418 | * |
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| 419 | * @return void |
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| 420 | */ |
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| 421 | abstract protected function clear(); |
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| 422 | } |
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| 423 |
PHP Analyzer performs a side-effects analysis of your code. A side-effect is basically anything that might be visible after the scope of the method is left.
Let’s take a look at an example:
If we look at the
getEmail()method, we can see that it has no side-effect. Whether you call this method or not, no future calls to other methods are affected by this. As such code as the following is useless:On the hand, if we look at the
setEmail(), this method _has_ side-effects. In the following case, we could not remove the method call: