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 ProductQuestion 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 ProductQuestion, and based on these observations, apply Extract Interface, too.
1 | <?php |
||
9 | class ProductQuestion extends DataObject |
||
|
|||
10 | { |
||
11 | |||
12 | /** |
||
13 | * Standard SS variable. |
||
14 | */ |
||
15 | private static $db = array( |
||
16 | 'InternalCode' => 'Varchar(30)', |
||
17 | 'Question' => 'Varchar(255)', |
||
18 | 'AnswerRequired' => 'Boolean', |
||
19 | 'Label' => 'Varchar(100)', |
||
20 | 'DefaultAnswer' => 'Varchar(150)', |
||
21 | 'DefaultFormField' => 'Varchar(255)', |
||
22 | 'Options' => 'Text', |
||
23 | "HasImages" => "Boolean", |
||
24 | "ApplyToAllProducts" => "Boolean" |
||
25 | ); |
||
26 | |||
27 | /** |
||
28 | * Standard SS variable. |
||
29 | */ |
||
30 | private static $casting = array( |
||
31 | 'Title' => 'Varchar', |
||
32 | 'FullName' => 'Varchar' |
||
33 | ); |
||
34 | |||
35 | /** |
||
36 | * Standard SS variable. |
||
37 | * Links questions to products |
||
38 | */ |
||
39 | private static $many_many = array( |
||
40 | 'Products' => 'Product' |
||
41 | ); |
||
42 | |||
43 | /** |
||
44 | * Standard SS variable. |
||
45 | * Links to folder for images |
||
46 | */ |
||
47 | private static $has_one = array( |
||
48 | 'Folder' => 'Folder' |
||
49 | ); |
||
50 | |||
51 | /** |
||
52 | * Standard SS variable. |
||
53 | * Links questions to products |
||
54 | */ |
||
55 | private static $summary_fields = array( |
||
56 | 'InternalCode' => 'InternalCode', |
||
57 | 'Question' => 'Question' |
||
58 | ); |
||
59 | |||
60 | /** |
||
61 | * Standard SS variable. |
||
62 | * Links questions to products |
||
63 | */ |
||
64 | private static $searchable_fields = array( |
||
65 | 'InternalCode' => 'PartialMatch', |
||
66 | 'Question' => 'Varchar(255)', |
||
67 | 'Label' => 'PartialMatch', |
||
68 | 'DefaultAnswer' => 'PartialMatch', |
||
69 | 'DefaultFormField' => 'PartialMatch', |
||
70 | 'Options' => 'PartialMatch', |
||
71 | "HasImages" => true |
||
72 | ); |
||
73 | |||
74 | /** |
||
75 | * Standard SS variable. |
||
76 | */ |
||
77 | private static $default_sort = [ |
||
78 | 'Question' => 'ASC', |
||
79 | 'ID' => 'ASC' |
||
80 | ]; |
||
81 | |||
82 | /** |
||
83 | * Standard SS variable. |
||
84 | */ |
||
85 | private static $defaults = array( |
||
86 | "DefaultFormField" => "TextField", |
||
87 | "DefaultAnswer" => "tba" |
||
88 | ); |
||
89 | |||
90 | /** |
||
91 | * form fields used without a list |
||
92 | * @var array |
||
93 | */ |
||
94 | private static $available_form_fields_free = array( |
||
95 | "TextField" => "Text Field", |
||
96 | "TextareaField" => "Text Field with several lines", |
||
97 | "DateField" => "Date Field", |
||
98 | "EmailField" => "Email Field" |
||
99 | ); |
||
100 | |||
101 | /** |
||
102 | * form fields used with a list |
||
103 | * @var array |
||
104 | */ |
||
105 | private static $available_form_fields_list = array( |
||
106 | "DropdownField" => "Dropdown Field", |
||
107 | "OptionSetField" => "Option list Field" |
||
108 | ); |
||
109 | |||
110 | /** |
||
111 | * Maximum number of products on the site before the CheckboxSetField is |
||
112 | * replaced with a GridField. |
||
113 | * This field is used for selecting the products the question applies to. |
||
114 | * |
||
115 | * @var Int |
||
116 | */ |
||
117 | private static $max_products_for_checkbox_set_field = 300; |
||
118 | |||
119 | /** |
||
120 | * Standard SS variable. |
||
121 | */ |
||
122 | private static $singular_name = "Product Question"; |
||
123 | public function i18n_singular_name() |
||
127 | |||
128 | /** |
||
129 | * Standard SS variable. |
||
130 | */ |
||
131 | private static $plural_name = "Product Questions"; |
||
132 | public function i18n_plural_name() |
||
141 | |||
142 | /** |
||
143 | * turns an option into potential file names |
||
144 | * e.g. red |
||
145 | * returns |
||
146 | * red.jpg, red.png, red.gif |
||
147 | * @param String $option |
||
148 | * @return Array |
||
149 | */ |
||
150 | public static function create_file_array_from_option($option) |
||
166 | |||
167 | /** |
||
168 | * Standard SS method |
||
169 | * @return FieldSet |
||
170 | */ |
||
171 | public function getCMSFields() |
||
311 | |||
312 | |||
313 | |||
314 | /** |
||
315 | * casted variable |
||
316 | * @return String |
||
317 | */ |
||
318 | public function FullName() |
||
326 | |||
327 | /** |
||
328 | * casted variable |
||
329 | * @return String |
||
330 | */ |
||
331 | public function Title() |
||
339 | |||
340 | /** |
||
341 | * |
||
342 | * @return FormField |
||
343 | */ |
||
344 | public function getFieldForProduct($product, $value = null) |
||
376 | |||
377 | public function getFieldForProductName(Product $product) |
||
381 | |||
382 | /** |
||
383 | * |
||
384 | * making sure all the data is clean |
||
385 | */ |
||
386 | public function onBeforeWrite() |
||
409 | |||
410 | public function onAfterWrite() |
||
417 | |||
418 | /** |
||
419 | * link to edit the record |
||
420 | * @param String | Null $action - e.g. edit |
||
421 | * @return String |
||
422 | */ |
||
423 | public function CMSEditLink($action = null) |
||
431 | } |
||
432 |
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.