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 TGifting 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 TGifting, and based on these observations, apply Extract Interface, too.
1 | <?php |
||
20 | trait TGifting |
||
21 | { |
||
22 | /** @var string */ |
||
23 | protected $giftItemId; |
||
24 | /** @var IPriceGroup */ |
||
25 | protected $giftPricing; |
||
26 | /** @var bool */ |
||
27 | protected $includeGiftWrapping; |
||
28 | /** @var string */ |
||
29 | protected $giftMessageTo; |
||
30 | /** @var string */ |
||
31 | protected $giftMessageFrom; |
||
32 | /** @var string */ |
||
33 | protected $giftMessageContent; |
||
34 | /** @var string */ |
||
35 | protected $giftCardTo; |
||
36 | /** @var string */ |
||
37 | protected $giftCardFrom; |
||
38 | /** @var string */ |
||
39 | protected $giftCardMessage; |
||
40 | /** @var string */ |
||
41 | protected $packslipTo; |
||
42 | /** @var string */ |
||
43 | protected $packslipFrom; |
||
44 | /** @var string */ |
||
45 | protected $packslipMessage; |
||
46 | /** @var string */ |
||
47 | protected $localizedFromLabel; |
||
48 | /** @var string */ |
||
49 | protected $localizedToLabel; |
||
50 | |||
51 | public function getEmptyGiftingPriceGroup() |
||
55 | |||
56 | public function getGiftItemId() |
||
60 | |||
61 | public function setGiftItemId($giftItemId) |
||
62 | { |
||
63 | $this->giftItemId = $this->cleanString($giftItemId, 20); |
||
64 | return $this; |
||
65 | } |
||
66 | |||
67 | public function getGiftPricing() |
||
71 | |||
72 | public function setGiftPricing(IPriceGroup $giftPricing) |
||
73 | { |
||
74 | $this->giftPricing = $giftPricing; |
||
75 | return $this; |
||
76 | } |
||
77 | |||
78 | public function getIncludeGiftWrapping() |
||
82 | |||
83 | public function setIncludeGiftWrapping($includeGiftWrapping) |
||
84 | { |
||
85 | $this->includeGiftWrapping = (bool) $includeGiftWrapping; |
||
86 | return $this; |
||
87 | } |
||
88 | |||
89 | public function getGiftMessageTo() |
||
93 | |||
94 | public function setGiftMessageTo($giftMessageTo) |
||
95 | { |
||
96 | $this->giftMessageTo = $giftMessageTo; |
||
97 | return $this; |
||
98 | } |
||
99 | |||
100 | public function getGiftMessageFrom() |
||
104 | |||
105 | public function setGiftMessageFrom($giftMessageFrom) |
||
106 | { |
||
107 | $this->giftMessageFrom = $giftMessageFrom; |
||
108 | return $this; |
||
109 | } |
||
110 | |||
111 | public function getGiftMessageContent() |
||
115 | |||
116 | public function setGiftMessageContent($giftMessageContent) |
||
117 | { |
||
118 | $this->giftMessageContent = $this->normalizeWhitespace($giftMessageContent); |
||
119 | return $this; |
||
120 | } |
||
121 | |||
122 | public function getGiftCardTo() |
||
126 | |||
127 | public function setGiftCardTo($giftCardTo) |
||
128 | { |
||
129 | $this->giftCardTo = $giftCardTo; |
||
130 | return $this; |
||
131 | } |
||
132 | |||
133 | public function getGiftCardFrom() |
||
137 | |||
138 | public function setGiftCardFrom($giftCardFrom) |
||
139 | { |
||
140 | $this->giftCardFrom = $giftCardFrom; |
||
141 | return $this; |
||
142 | } |
||
143 | |||
144 | public function getGiftCardMessage() |
||
148 | |||
149 | public function setGiftCardMessage($giftCardMessage) |
||
150 | { |
||
151 | $this->giftCardMessage = $this->normalizeWhitespace($giftCardMessage); |
||
152 | return $this; |
||
153 | } |
||
154 | |||
155 | public function getPackslipTo() |
||
159 | |||
160 | public function setPackslipTo($packslipTo) |
||
161 | { |
||
162 | $this->packslipTo = $packslipTo; |
||
163 | return $this; |
||
164 | } |
||
165 | |||
166 | public function getPackslipFrom() |
||
170 | |||
171 | public function setPackslipFrom($packslipFrom) |
||
172 | { |
||
173 | $this->packslipFrom = $packslipFrom; |
||
174 | return $this; |
||
175 | } |
||
176 | |||
177 | public function getPackslipMessage() |
||
181 | |||
182 | public function setPackslipMessage($packslipMessage) |
||
183 | { |
||
184 | $this->packslipMessage = $this->normalizeWhitespace($packslipMessage); |
||
185 | return $this; |
||
186 | } |
||
187 | |||
188 | public function getLocalizedFromLabel() |
||
192 | |||
193 | public function setLocalizedFromLabel($localizedFromLabel) |
||
194 | { |
||
195 | $this->localizedFromLabel = $localizedFromLabel; |
||
196 | return $this; |
||
197 | } |
||
198 | |||
199 | public function getLocalizedToLabel() |
||
203 | |||
204 | public function setLocalizedToLabel($localizedToLabel) |
||
205 | { |
||
206 | $this->localizedToLabel = $localizedToLabel; |
||
207 | return $this; |
||
208 | } |
||
209 | |||
210 | /** |
||
211 | * Serialize gifting data. |
||
212 | * |
||
213 | * @return string |
||
214 | */ |
||
215 | protected function serializeGifting() |
||
216 | { |
||
217 | $serializedData = $this->serializeGift() |
||
218 | . $this->serializeGiftingGiftCard() |
||
219 | . $this->serializeGiftingPackslip(); |
||
220 | return $serializedData ? "<Gifting>$serializedData</Gifting>" : ''; |
||
221 | } |
||
222 | |||
223 | /** |
||
224 | * Serialize the "Gift" gifting data. Will only be included if there is |
||
225 | * a gift item id set. |
||
226 | * |
||
227 | * @return string |
||
228 | */ |
||
229 | protected function serializeGift() |
||
230 | { |
||
231 | if ($this->getGiftItemId()) { |
||
232 | $pricing = $this->getGiftPricing(); |
||
233 | return '<Gift>' |
||
234 | . "<ItemId>{$this->xmlEncode($this->getGiftItemId())}</ItemId>" |
||
235 | . ($pricing ? $pricing->setRootNodeName('Pricing')->serialize() : '') |
||
236 | . $this->serializeGiftingGiftMessage() |
||
237 | . '</Gift>'; |
||
238 | } |
||
239 | return ''; |
||
240 | } |
||
241 | |||
242 | /** |
||
243 | * Serialize the gift message data. Will only be included if there |
||
244 | * are valid to and from fields. |
||
245 | * |
||
246 | * @return string |
||
247 | */ |
||
248 | protected function serializeGiftingGiftMessage() |
||
249 | { |
||
250 | $messageSerialization = $this->serializeGiftingMessage( |
||
251 | $this->getGiftMessageTo(), |
||
252 | $this->getGiftMessageFrom(), |
||
253 | $this->getGiftMessageContent() |
||
254 | ); |
||
255 | return $messageSerialization ? $messageSerialization : ''; |
||
256 | } |
||
257 | |||
258 | /** |
||
259 | * Serialize the gift card message data. Will only be included if there |
||
260 | * are valid to and from fields. |
||
261 | * |
||
262 | * @return string |
||
263 | */ |
||
264 | protected function serializeGiftingGiftCard() |
||
265 | { |
||
266 | $messageSerialization = $this->serializeGiftingMessage( |
||
267 | $this->getGiftCardTo(), |
||
268 | $this->getGiftCardFrom(), |
||
269 | $this->getGiftCardMessage() |
||
270 | ); |
||
271 | // If the gifting includes gift wrapping, the gift card node |
||
272 | // must always be included. |
||
273 | return ($messageSerialization || $this->getIncludeGiftWrapping()) |
||
274 | ? "<GiftCard>$messageSerialization</GiftCard>" |
||
275 | : ''; |
||
276 | } |
||
277 | |||
278 | /** |
||
279 | * Serialize the packslip message data. Will only be included if there |
||
280 | * are valid to and from fields. |
||
281 | * |
||
282 | * @return string |
||
283 | */ |
||
284 | protected function serializeGiftingPackslip() |
||
285 | { |
||
286 | $messageSerialization = $this->serializeGiftingMessage( |
||
287 | $this->getPackslipTo(), |
||
288 | $this->getPackslipFrom(), |
||
289 | $this->getPackslipMessage() |
||
290 | ); |
||
291 | return $messageSerialization ? "<Packslip>$messageSerialization</Packslip>" : ''; |
||
292 | } |
||
293 | |||
294 | /** |
||
295 | * Serialize a gifting message from, to and message. Will only return a |
||
296 | * serialization if at least a from and to name are given. |
||
297 | * |
||
298 | * @param string |
||
299 | * @param string |
||
300 | * @param string |
||
301 | * @return string |
||
302 | */ |
||
303 | protected function serializeGiftingMessage($toName, $fromName, $messageText) |
||
304 | { |
||
305 | $localizedTo = $this->serializeOptionalAttribute( |
||
306 | 'localizedDisplayText', |
||
307 | $this->xmlEncode($this->getLocalizedToLabel()) |
||
308 | ); |
||
309 | $localizedFrom = $this->serializeOptionalAttribute( |
||
310 | 'localizedDisplayText', |
||
311 | $this->xmlEncode($this->getLocalizedFromLabel()) |
||
312 | ); |
||
313 | return $toName && $fromName |
||
314 | ? '<Message>' |
||
315 | . "<To $localizedTo>{$this->xmlEncode($toName)}</To>" |
||
316 | . "<From $localizedFrom>{$this->xmlEncode($fromName)}</From>" |
||
317 | . $this->serializeOptionalXmlEncodedValue('Message', $messageText) |
||
318 | . '</Message>' |
||
319 | : ''; |
||
320 | } |
||
321 | |||
322 | /** |
||
323 | * Extract gifting pricing from the payload in the DOMXPath and, if it is |
||
324 | * included in the serialized data, deserialize it into a new price group. |
||
325 | * |
||
326 | * @return self |
||
327 | */ |
||
328 | View Code Duplication | protected function deserializeGiftPricing(DOMXPath $xpath) |
|
329 | { |
||
330 | $priceNode = $xpath->query('x:Gifting/x:Gift/x:Pricing')->item(0); |
||
331 | if ($priceNode) { |
||
332 | $this->setGiftPricing( |
||
333 | $this->getEmptyGiftingPriceGroup()->deserialize($priceNode->C14N()) |
||
334 | ); |
||
335 | } |
||
336 | return $this; |
||
337 | } |
||
338 | |||
339 | /** |
||
340 | * Serialize an optional element containing a string. The value will be |
||
341 | * xml-encoded if is not null. |
||
342 | * |
||
343 | * @param string |
||
344 | * @param string |
||
345 | * @return string |
||
346 | */ |
||
347 | abstract protected function serializeOptionalXmlEncodedValue($name, $value); |
||
348 | |||
349 | /** |
||
350 | * encode the passed in string to be safe for xml if it is not null, |
||
351 | * otherwise simply return the null parameter. |
||
352 | * |
||
353 | * @param string|null |
||
354 | * @return string|null |
||
355 | */ |
||
356 | abstract protected function xmlEncode($value = null); |
||
357 | } |
||
358 |
This check looks for methods that are used by a trait but not required by it.
To illustrate, let’s look at the following code example
The trait
Idable
provides a methodequalsId
that in turn relies on the methodgetId()
. If this method does not exist on a class mixing in this trait, the method will fail.Adding the
getId()
as an abstract method to the trait will make sure it is available.