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 BaseElement 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 BaseElement, and based on these observations, apply Extract Interface, too.
| 1 | <?php  | 
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| 6 | class BaseElement extends Widget  | 
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| 7 | { | 
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| 8 | /**  | 
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| 9 | * @var array $db  | 
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| 10 | */  | 
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| 11 | private static $db = array(  | 
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| 12 | 'ExtraClass' => 'Varchar(255)',  | 
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| 13 | 'HideTitle' => 'Boolean',  | 
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| 14 | 'AvailableGlobally' => 'Boolean(1)'  | 
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| 15 | );  | 
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| 16 | |||
| 17 | /**  | 
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| 18 | * @var array $has_one  | 
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| 19 | */  | 
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| 20 | private static $has_one = array(  | 
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| 21 | 'List' => 'ElementList' // optional.  | 
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| 22 | );  | 
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| 23 | |||
| 24 | /**  | 
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| 25 | * @var array $has_many  | 
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| 26 | */  | 
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| 27 | private static $has_many = array(  | 
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| 28 | 'VirtualClones' => 'ElementVirtualLinked'  | 
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| 29 | );  | 
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| 30 | |||
| 31 | /**  | 
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| 32 | * @var string  | 
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| 33 | */  | 
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| 34 | private static $title = 'Content Block';  | 
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| 35 | |||
| 36 | /**  | 
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| 37 | * @var string  | 
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| 38 | */  | 
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| 39 | private static $singular_name = 'Content Block';  | 
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| 40 | |||
| 41 | /**  | 
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| 42 | * @var array  | 
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| 43 | */  | 
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| 44 | private static $summary_fields = array(  | 
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| 45 | 'ID' => 'ID',  | 
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| 46 | 'Title' => 'Title',  | 
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| 47 | 'ElementType' => 'Type'  | 
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| 48 | );  | 
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| 49 | |||
| 50 | /**  | 
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| 51 | * @var array  | 
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| 52 | */  | 
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| 53 | private static $searchable_fields = array(  | 
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| 54 | 'ID' => array(  | 
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| 55 | 'field' => 'NumericField'  | 
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| 56 | ),  | 
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| 57 | 'Title',  | 
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| 58 | 'LastEdited',  | 
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| 59 | 'ClassName',  | 
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| 60 | 'AvailableGlobally'  | 
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| 61 | );  | 
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| 62 | |||
| 63 | /**  | 
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| 64 | * @var boolean  | 
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| 65 | */  | 
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| 66 | private static $enable_title_in_template = false;  | 
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| 67 | |||
| 68 | /**  | 
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| 69 | * Enable for backwards compatibility  | 
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| 70 | *  | 
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| 71 | * @var boolean  | 
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| 72 | */  | 
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| 73 | private static $disable_pretty_anchor_name = false;  | 
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| 74 | |||
| 75 | /**  | 
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| 76 | * Store used anchor names, this is to avoid title clashes  | 
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| 77 | * when calling 'getAnchor'  | 
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| 78 | *  | 
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| 79 | * @var array  | 
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| 80 | */  | 
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| 81 | protected static $_used_anchors = array();  | 
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| 82 | |||
| 83 | /**  | 
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| 84 | * For caching 'getAnchor'  | 
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| 85 | *  | 
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| 86 | * @var string  | 
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| 87 | */  | 
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| 88 | protected $_anchor = null;  | 
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| 89 | |||
| 90 | /**  | 
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| 91 | * @var Object  | 
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| 92 | * The virtual owner VirtualLinkedElement  | 
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| 93 | */  | 
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| 94 | public $virtualOwner;  | 
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| 95 | |||
| 96 | /**  | 
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| 97 | * @config  | 
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| 98 | * Elements available globally by default  | 
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| 99 | */  | 
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| 100 | private static $default_global_elements = true;  | 
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| 101 | |||
| 102 |      public function populateDefaults() { | 
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| 106 | |||
| 107 | public function getCMSFields()  | 
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| 200 | |||
| 201 | /**  | 
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| 202 | * Version viewer must only be added at if this is the final getCMSFields for a class.  | 
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| 203 | * in order to avoid having to rename all fields from eg Root.Main to Root.Current.Main  | 
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| 204 | * To do this we test if getCMSFields is from the current class  | 
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| 205 | */  | 
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| 206 | public function isEndofLine($className)  | 
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| 216 | |||
| 217 | |||
| 218 | public function onBeforeWrite()  | 
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| 232 | |||
| 233 | /**  | 
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| 234 | * Ensure that if there are elements that are virtualised from this element  | 
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| 235 | * that we move the original element to replace one of the virtual elements  | 
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| 236 | * But only if it's a delete not an unpublish  | 
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| 237 | */  | 
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| 238 |     public function onBeforeDelete() { | 
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| 290 | |||
| 291 | /**  | 
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| 292 | * @return string  | 
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| 293 | */  | 
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| 294 | public function i18n_singular_name()  | 
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| 298 | |||
| 299 | /**  | 
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| 300 | * @return string  | 
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| 301 | */  | 
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| 302 | public function getElementType()  | 
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| 306 | |||
| 307 | /**  | 
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| 308 | * @return string  | 
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| 309 | */  | 
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| 310 | View Code Duplication | public function getTitle()  | 
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| 322 | |||
| 323 | /**  | 
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| 324 | * Get a unique anchor name  | 
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| 325 | *  | 
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| 326 | * @return string  | 
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| 327 | */  | 
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| 328 |     public function getAnchor() { | 
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| 359 | |||
| 360 | /**  | 
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| 361 | * @return string  | 
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| 362 | */  | 
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| 363 | View Code Duplication | public function getCMSTitle()  | 
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| 374 | |||
| 375 | public function ControllerTop()  | 
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| 379 | |||
| 380 | public function getPage()  | 
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| 398 | |||
| 399 | /**  | 
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| 400 |      * Override the {@link Widget::forTemplate()} method so that holders are not rendered twice. The controller should | 
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| 401 | * render with widget inside the  | 
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| 402 | *  | 
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| 403 | * @return HTML  | 
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| 404 | */  | 
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| 405 | public function forTemplate($holder = true)  | 
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| 413 | |||
| 414 | /**  | 
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| 415 | * @return string  | 
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| 416 | */  | 
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| 417 |     public function getEditLink() { | 
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| 420 | |||
| 421 | /**  | 
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| 422 | * @return string  | 
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| 423 | */  | 
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| 424 |     public function CMSEditLink($inList = false) { | 
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| 457 | |||
| 458 | View Code Duplication |     public function PageLink() { | 
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| 465 | |||
| 466 | View Code Duplication |     public function PageCMSEditLink() { | 
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| 473 | |||
| 474 |     public static function all_allowed_elements() { | 
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| 505 | |||
| 506 | public function getDefaultSearchContext()  | 
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| 522 | |||
| 523 |     public function setVirtualOwner(ElementVirtualLinked $virtualOwner) { | 
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| 526 | |||
| 527 | /**  | 
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| 528 | * Finds and returns elements  | 
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| 529 | * that are virtual elements which link to this element  | 
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| 530 | */  | 
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| 531 |     public function getVirtualLinkedElements() { | 
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| 534 | |||
| 535 | /**  | 
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| 536 | * Finds and returns published elements  | 
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| 537 | * that are virtual elements which link to this element  | 
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| 538 | */  | 
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| 539 |     public function getPublishedVirtualLinkedElements() { | 
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| 546 | }  | 
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| 547 | 
You can fix this by adding a namespace to your class:
When choosing a vendor namespace, try to pick something that is not too generic to avoid conflicts with other libraries.