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 Collection 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 Collection, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 19 | class Collection extends SplObjectStorage implements CollectionInterface |
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| 20 | { |
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| 21 | |||
| 22 | /** |
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| 23 | * a unique string for identifying this collection |
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| 24 | * |
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| 25 | * @type string $collection_identifier |
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| 26 | */ |
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| 27 | protected $collection_identifier; |
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| 28 | |||
| 29 | /** |
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| 30 | * an interface (or class) name to be used for restricting the type of objects added to the storage |
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| 31 | * this should be set from within the child class constructor |
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| 32 | * |
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| 33 | * @type string $interface |
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| 34 | */ |
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| 35 | protected $collection_interface; |
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| 36 | |||
| 37 | |||
| 38 | /** |
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| 39 | * Collection constructor |
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| 40 | * |
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| 41 | * @param string $collection_interface |
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| 42 | * @throws InvalidInterfaceException |
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| 43 | */ |
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| 44 | public function __construct($collection_interface) |
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| 49 | |||
| 50 | |||
| 51 | /** |
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| 52 | * @return string |
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| 53 | */ |
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| 54 | public function collectionIdentifier() |
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| 58 | |||
| 59 | |||
| 60 | /** |
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| 61 | * creates a very readable unique 9 character identifier like: CF2-532-DAC |
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| 62 | * and appends it to the non-qualified class name, ex: ThingCollection-CF2-532-DAC |
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| 63 | * |
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| 64 | * @return void |
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| 65 | */ |
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| 66 | protected function setCollectionIdentifier() |
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| 79 | |||
| 80 | |||
| 81 | /** |
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| 82 | * setCollectionInterface |
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| 83 | * |
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| 84 | * @access protected |
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| 85 | * @param string $collection_interface |
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| 86 | * @throws \EventEspresso\core\exceptions\InvalidInterfaceException |
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| 87 | */ |
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| 88 | View Code Duplication | protected function setCollectionInterface($collection_interface) |
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| 95 | |||
| 96 | |||
| 97 | /** |
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| 98 | * add |
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| 99 | * attaches an object to the Collection |
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| 100 | * and sets any supplied data associated with the current iterator entry |
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| 101 | * by calling EE_Object_Collection::set_identifier() |
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| 102 | * |
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| 103 | * @access public |
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| 104 | * @param $object |
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| 105 | * @param mixed $identifier |
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| 106 | * @return bool |
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| 107 | * @throws InvalidEntityException |
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| 108 | * @throws DuplicateCollectionIdentifierException |
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| 109 | */ |
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| 110 | public function add($object, $identifier = null) |
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| 122 | |||
| 123 | |||
| 124 | /** |
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| 125 | * setIdentifier |
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| 126 | * Sets the data associated with an object in the Collection |
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| 127 | * if no $identifier is supplied, then the spl_object_hash() is used |
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| 128 | * |
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| 129 | * @access public |
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| 130 | * @param $object |
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| 131 | * @param mixed $identifier |
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| 132 | * @return bool |
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| 133 | */ |
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| 134 | View Code Duplication | public function setIdentifier($object, $identifier = null) |
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| 150 | |||
| 151 | |||
| 152 | /** |
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| 153 | * get |
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| 154 | * finds and returns an object in the Collection based on the identifier that was set using addObject() |
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| 155 | * PLZ NOTE: the pointer is reset to the beginning of the collection before returning |
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| 156 | * |
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| 157 | * @access public |
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| 158 | * @param mixed $identifier |
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| 159 | * @return mixed |
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| 160 | */ |
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| 161 | View Code Duplication | public function get($identifier) |
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| 174 | |||
| 175 | |||
| 176 | /** |
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| 177 | * has |
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| 178 | * returns TRUE or FALSE |
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| 179 | * depending on whether the object is within the Collection |
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| 180 | * based on the supplied $identifier |
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| 181 | * |
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| 182 | * @access public |
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| 183 | * @param mixed $identifier |
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| 184 | * @return bool |
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| 185 | */ |
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| 186 | View Code Duplication | public function has($identifier) |
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| 198 | |||
| 199 | |||
| 200 | /** |
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| 201 | * hasObject |
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| 202 | * returns TRUE or FALSE depending on whether the supplied object is within the Collection |
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| 203 | * |
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| 204 | * @access public |
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| 205 | * @param $object |
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| 206 | * @return bool |
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| 207 | */ |
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| 208 | public function hasObject($object) |
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| 212 | |||
| 213 | |||
| 214 | /** |
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| 215 | * hasObjects |
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| 216 | * returns true if there are objects within the Collection, and false if it is empty |
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| 217 | * |
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| 218 | * @access public |
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| 219 | * @return bool |
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| 220 | */ |
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| 221 | public function hasObjects() |
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| 225 | |||
| 226 | |||
| 227 | /** |
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| 228 | * isEmpty |
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| 229 | * returns true if there are no objects within the Collection, and false if there are |
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| 230 | * |
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| 231 | * @access public |
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| 232 | * @return bool |
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| 233 | */ |
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| 234 | public function isEmpty() |
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| 238 | |||
| 239 | |||
| 240 | /** |
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| 241 | * remove |
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| 242 | * detaches an object from the Collection |
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| 243 | * |
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| 244 | * @access public |
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| 245 | * @param $object |
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| 246 | * @return bool |
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| 247 | */ |
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| 248 | public function remove($object) |
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| 253 | |||
| 254 | |||
| 255 | /** |
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| 256 | * setCurrent |
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| 257 | * advances pointer to the object whose identifier matches that which was provided |
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| 258 | * |
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| 259 | * @access public |
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| 260 | * @param mixed $identifier |
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| 261 | * @return boolean |
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| 262 | */ |
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| 263 | View Code Duplication | public function setCurrent($identifier) |
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| 274 | |||
| 275 | |||
| 276 | /** |
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| 277 | * setCurrentUsingObject |
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| 278 | * advances pointer to the provided object |
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| 279 | * |
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| 280 | * @access public |
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| 281 | * @param $object |
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| 282 | * @return boolean |
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| 283 | */ |
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| 284 | public function setCurrentUsingObject($object) |
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| 295 | |||
| 296 | |||
| 297 | /** |
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| 298 | * Returns the object occupying the index before the current object, |
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| 299 | * unless this is already the first object, in which case it just returns the first object |
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| 300 | * |
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| 301 | * @return mixed |
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| 302 | */ |
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| 303 | public function previous() |
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| 312 | |||
| 313 | |||
| 314 | /** |
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| 315 | * Returns the index of a given object, or false if not found |
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| 316 | * |
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| 317 | * @see http://stackoverflow.com/a/8736013 |
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| 318 | * @param $object |
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| 319 | * @return boolean|int|string |
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| 320 | */ |
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| 321 | public function indexOf($object) |
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| 333 | |||
| 334 | |||
| 335 | /** |
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| 336 | * Returns the object at the given index |
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| 337 | * |
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| 338 | * @see http://stackoverflow.com/a/8736013 |
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| 339 | * @param int $index |
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| 340 | * @return mixed |
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| 341 | */ |
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| 342 | public function objectAtIndex($index) |
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| 348 | |||
| 349 | |||
| 350 | /** |
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| 351 | * Returns the sequence of objects as specified by the offset and length |
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| 352 | * |
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| 353 | * @see http://stackoverflow.com/a/8736013 |
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| 354 | * @param int $offset |
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| 355 | * @param int $length |
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| 356 | * @return array |
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| 357 | */ |
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| 358 | public function slice($offset, $length) |
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| 367 | |||
| 368 | |||
| 369 | /** |
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| 370 | * Inserts an object at a certain point |
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| 371 | * |
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| 372 | * @see http://stackoverflow.com/a/8736013 |
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| 373 | * @param mixed $object A single object |
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| 374 | * @param int $index |
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| 375 | * @param mixed $identifier |
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| 376 | * @return bool |
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| 377 | * @throws DuplicateCollectionIdentifierException |
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| 378 | * @throws InvalidEntityException |
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| 379 | */ |
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| 380 | public function insertObjectAt($object, $index, $identifier = null) |
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| 407 | |||
| 408 | |||
| 409 | /** |
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| 410 | * Inserts an object (or an array of objects) at a certain point |
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| 411 | * |
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| 412 | * @see http://stackoverflow.com/a/8736013 |
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| 413 | * @param mixed $objects A single object or an array of objects |
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| 414 | * @param int $index |
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| 415 | */ |
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| 416 | public function insertAt($objects, $index) |
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| 448 | |||
| 449 | |||
| 450 | /** |
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| 451 | * Removes the object at the given index |
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| 452 | * |
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| 453 | * @see http://stackoverflow.com/a/8736013 |
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| 454 | * @param int $index |
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| 455 | */ |
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| 456 | public function removeAt($index) |
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| 460 | |||
| 461 | |||
| 462 | /** |
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| 463 | * detaches ALL objects from the Collection |
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| 464 | */ |
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| 465 | public function detachAll() |
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| 474 | |||
| 475 | |||
| 476 | /** |
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| 477 | * unsets and detaches ALL objects from the Collection |
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| 478 | */ |
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| 479 | public function trashAndDetachAll() |
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| 489 | } |
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| 490 |
This check marks implicit conversions of arrays to boolean values in a comparison. While in PHP an empty array is considered to be equal (but not identical) to false, this is not always apparent.
Consider making the comparison explicit by using
empty(..)or! empty(...)instead.