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:
| 1 | <?php  | 
            ||
| 12 | abstract class Predefined_Options_Field extends Field { | 
            ||
| 13 | |||
| 14 | /**  | 
            ||
| 15 | * Stores the raw, unprocessed field options  | 
            ||
| 16 | *  | 
            ||
| 17 | * @var array(array|callable)  | 
            ||
| 18 | */  | 
            ||
| 19 | protected $option_collections = array();  | 
            ||
| 20 | |||
| 21 | /**  | 
            ||
| 22 | * Check if an array is indexed  | 
            ||
| 23 | *  | 
            ||
| 24 | * @param array $array  | 
            ||
| 25 | * @return boolean  | 
            ||
| 26 | */  | 
            ||
| 27 | 	protected function is_indexed_array( $array ) { | 
            ||
| 30 | |||
| 31 | /**  | 
            ||
| 32 | * Set the options of this field.  | 
            ||
| 33 | * Accepts either array of data or a callback that returns the data.  | 
            ||
| 34 | *  | 
            ||
| 35 | * @param array|callable $options  | 
            ||
| 36 | * @return self $this  | 
            ||
| 37 | 9 | */  | 
            |
| 38 | 9 | View Code Duplication | 	public function set_options( $options ) { | 
            
| 47 | |||
| 48 | /**  | 
            ||
| 49 | * Add new options to this field.  | 
            ||
| 50 | * Accepts either array of data or a callback that returns the data.  | 
            ||
| 51 | *  | 
            ||
| 52 | * @param array|callable $options  | 
            ||
| 53 | * @return self $this  | 
            ||
| 54 | 13 | */  | 
            |
| 55 | 13 | View Code Duplication | 	public function add_options( $options ) { | 
            
| 64 | |||
| 65 | /**  | 
            ||
| 66 | * Get a populated array of options executing any callbacks in the process  | 
            ||
| 67 | *  | 
            ||
| 68 | * @return array  | 
            ||
| 69 | */  | 
            ||
| 70 | 	protected function load_options() { | 
            ||
| 91 | |||
| 92 | /**  | 
            ||
| 93 | * Retrieve the current options.  | 
            ||
| 94 | *  | 
            ||
| 95 | * @return array  | 
            ||
| 96 | 13 | */  | 
            |
| 97 | 13 | 	public function get_options() { | 
            |
| 100 | |||
| 101 | /**  | 
            ||
| 102 | * Retrieve the current options' values only.  | 
            ||
| 103 | *  | 
            ||
| 104 | * @return array $options  | 
            ||
| 105 | */  | 
            ||
| 106 | 	protected function get_options_values() { | 
            ||
| 110 | |||
| 111 | /**  | 
            ||
| 112 | * Changes the options array structure. This is needed to keep the array items order when it is JSON encoded.  | 
            ||
| 113 | * Will also work with a callable that returns an array.  | 
            ||
| 114 | *  | 
            ||
| 115 | * @param array|callable $options  | 
            ||
| 116 | * @return array  | 
            ||
| 117 | */  | 
            ||
| 118 | 	protected function parse_options( $options, $stringify_value = false ) { | 
            ||
| 134 | |||
| 135 | /**  | 
            ||
| 136 | * Get an array of all values that are both in the passed array and the predefined list of options  | 
            ||
| 137 | *  | 
            ||
| 138 | * @param array $values  | 
            ||
| 139 | * @return array  | 
            ||
| 140 | */  | 
            ||
| 141 | 	protected function get_values_from_options( $values ) { | 
            ||
| 146 | }  | 
            ||
| 147 |