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 Complex_Field 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 Complex_Field, and based on these observations, apply Extract Interface, too.
1 | <?php |
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16 | class Complex_Field extends Field { |
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17 | |||
18 | /** |
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19 | * Visual layout type constants |
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20 | */ |
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21 | const LAYOUT_GRID = 'grid'; // default |
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22 | |||
23 | const LAYOUT_TABBED_HORIZONTAL = 'tabbed-horizontal'; |
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24 | |||
25 | const LAYOUT_TABBED_VERTICAL = 'tabbed-vertical'; |
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26 | |||
27 | /** |
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28 | * Default field value |
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29 | * |
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30 | * @var array |
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31 | */ |
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32 | protected $default_value = array(); |
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33 | |||
34 | /** |
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35 | * Complex field layout |
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36 | * |
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37 | * @var string static::LAYOUT_* constant |
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38 | */ |
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39 | protected $layout = self::LAYOUT_GRID; |
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40 | |||
41 | /** |
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42 | * Value tree describing the complex values and all groups with their child fields |
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43 | * |
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44 | * @var array |
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45 | */ |
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46 | protected $value_tree = array(); |
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47 | |||
48 | /** |
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49 | * Array of groups registered for this complex field |
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50 | * |
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51 | * @var array |
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52 | */ |
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53 | protected $groups = array(); |
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54 | |||
55 | /** |
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56 | * Minimum number of entries. -1 for no limit |
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57 | * |
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58 | * @var integer |
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59 | */ |
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60 | protected $values_min = -1; |
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61 | |||
62 | /** |
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63 | * Maximum number of entries. -1 for no limit |
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64 | * |
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65 | * @var integer |
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66 | */ |
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67 | protected $values_max = -1; |
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68 | |||
69 | /** |
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70 | * Default entry state - collapsed or not |
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71 | * |
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72 | * @var boolean |
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73 | */ |
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74 | protected $collapsed = false; |
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75 | |||
76 | /** |
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77 | * Entry labels |
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78 | * These are translated in init() |
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79 | * |
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80 | * @var array |
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81 | */ |
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82 | public $labels = array( |
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83 | 'singular_name' => 'Entry', |
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84 | 'plural_name' => 'Entries', |
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85 | ); |
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86 | |||
87 | /** |
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88 | * Create a field from a certain type with the specified label. |
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89 | * |
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90 | * @param string $type Field type |
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91 | * @param string $name Field name |
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92 | * @param string $label Field label |
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93 | */ |
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94 | public function __construct( $type, $name, $label ) { |
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98 | |||
99 | /** |
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100 | * Initialization tasks. |
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101 | */ |
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102 | public function init() { |
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109 | |||
110 | /** |
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111 | * Set array of hierarchy field names |
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112 | */ |
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113 | public function set_hierarchy( $hierarchy ) { |
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117 | |||
118 | /** |
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119 | * Propagate hierarchy to child fields |
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120 | */ |
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121 | public function update_child_hierarchy() { |
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128 | |||
129 | /** |
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130 | * Activate the field once the container is attached. |
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131 | */ |
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132 | public function activate() { |
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139 | |||
140 | /** |
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141 | * Set the datastore of this field and propagate it to children |
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142 | * |
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143 | * @param Datastore_Interface $datastore |
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144 | */ |
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145 | View Code Duplication | public function set_datastore( Datastore_Interface $datastore, $set_as_default = false ) { |
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157 | |||
158 | /** |
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159 | * Retrieve all groups of fields. |
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160 | * |
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161 | * @return array $fields |
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162 | */ |
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163 | public function get_fields() { |
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174 | |||
175 | /** |
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176 | * Add a set/group of fields. |
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177 | * |
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178 | * Accepted param variations: |
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179 | * - array<Field> $fields |
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180 | * - string $group_name, array<Field> $fields |
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181 | * - string $group_name, string $group_label, array<Field> $fields |
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182 | * |
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183 | * @return $this |
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184 | */ |
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185 | public function add_fields() { |
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221 | |||
222 | /** |
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223 | * Retrieve the groups of this field. |
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224 | * |
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225 | * @return array |
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226 | */ |
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227 | public function get_group_names() { |
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230 | |||
231 | /** |
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232 | * Retrieve a group by its name. |
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233 | * |
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234 | * @param string $group_name Group name |
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235 | * @return Group_Field $group_object Group object |
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236 | */ |
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237 | public function get_group_by_name( $group_name ) { |
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248 | |||
249 | /** |
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250 | * Set the group label Underscore template. |
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251 | * |
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252 | * @param string|callable $template |
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253 | * @return $this |
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254 | */ |
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255 | public function set_header_template( $template ) { |
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270 | |||
271 | /** |
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272 | * Set the field labels. |
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273 | * Currently supported values: |
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274 | * - singular_name - the singular entry label |
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275 | * - plural_name - the plural entries label |
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276 | * |
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277 | * @param array $labels Labels |
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278 | */ |
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279 | public function setup_labels( $labels ) { |
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283 | |||
284 | /** |
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285 | * Return a clone of a field with hierarchy settings applied |
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286 | * |
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287 | * @param Field $field |
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288 | * @param Field $parent_field |
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289 | * @param int $group_index |
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290 | * @return Field |
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291 | */ |
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292 | public function get_clone_under_field_in_hierarchy( $field, $parent_field, $group_index = 0 ) { |
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298 | |||
299 | protected function get_prefilled_group_fields( $group_fields, $group_values, $group_index ) { |
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312 | |||
313 | protected function get_prefilled_groups( $value_tree ) { |
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329 | |||
330 | /** |
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331 | * Load the field value from an input array based on it's name. |
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332 | * |
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333 | * @param array $input Array of field names and values. |
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334 | */ |
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335 | public function set_value_from_input( $input ) { |
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374 | |||
375 | /** |
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376 | * Save all contained groups of fields. |
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377 | */ |
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378 | public function save() { |
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401 | |||
402 | /** |
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403 | * {@inheritDoc} |
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404 | */ |
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405 | public function set_value( $value ) { |
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409 | |||
410 | /** |
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411 | * Return the full value tree of all groups and their fields |
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412 | * |
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413 | * @return mixed |
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414 | */ |
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415 | protected function get_value_tree() { |
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418 | |||
419 | /** |
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420 | * Set the full value tree of all groups and their fields |
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421 | * |
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422 | * @see Internal Glossary in DEVELOPMENT.MD |
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423 | */ |
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424 | protected function set_value_tree( $value_tree ) { |
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427 | |||
428 | /** |
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429 | * Return a differently formatted value for end-users |
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430 | * |
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431 | * @return mixed |
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432 | */ |
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433 | public function get_formatted_value() { |
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453 | |||
454 | /** |
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455 | * Returns an array that holds the field data, suitable for JSON representation. |
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456 | * |
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457 | * @param bool $load Should the value be loaded from the database or use the value from the current instance. |
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458 | * @return array |
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459 | */ |
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460 | public function to_json( $load ) { |
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507 | |||
508 | /** |
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509 | * Modify the layout of this field. |
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510 | * |
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511 | * @param string $layout |
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512 | */ |
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513 | public function set_layout( $layout ) { |
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532 | |||
533 | /** |
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534 | * Get the minimum number of entries. |
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535 | * |
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536 | * @return int $min |
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537 | */ |
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538 | public function get_min() { |
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541 | |||
542 | /** |
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543 | * Set the minimum number of entries. |
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544 | * |
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545 | * @param int $min |
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546 | */ |
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547 | public function set_min( $min ) { |
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551 | |||
552 | /** |
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553 | * Get the maximum number of entries. |
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554 | * |
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555 | * @return int $max |
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556 | */ |
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557 | public function get_max() { |
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560 | |||
561 | /** |
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562 | * Set the maximum number of entries. |
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563 | * |
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564 | * @param int $max |
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565 | */ |
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566 | public function set_max( $max ) { |
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570 | |||
571 | /** |
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572 | * Get collapsed state |
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573 | * |
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574 | * @return bool |
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575 | */ |
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576 | public function get_collapsed() { |
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579 | |||
580 | /** |
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581 | * Change the groups initial collapse state. |
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582 | * This state relates to the state of which the groups are rendered. |
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583 | * |
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584 | * @param bool $collapsed |
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585 | */ |
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586 | public function set_collapsed( $collapsed = true ) { |
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590 | } |
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591 |