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 Paystack 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 Paystack, and based on these observations, apply Extract Interface, too.
1 | <?php |
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19 | class Paystack |
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20 | { |
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21 | /** |
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22 | * Transaction Verification Successful |
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23 | */ |
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24 | const VS = 'Verification successful'; |
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25 | |||
26 | /** |
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27 | * Invalid Transaction reference |
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28 | */ |
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29 | const ITF = "Invalid transaction reference"; |
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30 | |||
31 | /** |
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32 | * Issue Secret Key from your Paystack Dashboard |
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33 | * @var string |
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34 | */ |
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35 | protected $secretKey; |
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36 | |||
37 | /** |
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38 | * Instance of Client |
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39 | * @var Client |
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40 | */ |
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41 | protected $client; |
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42 | |||
43 | /** |
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44 | * Response from requests made to Paystack |
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45 | * @var mixed |
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46 | */ |
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47 | protected $response; |
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48 | |||
49 | /** |
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50 | * Paystack API base Url |
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51 | * @var string |
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52 | */ |
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53 | protected $baseUrl; |
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54 | |||
55 | /** |
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56 | * Authorization Url - Paystack payment page |
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57 | * @var string |
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58 | */ |
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59 | protected $authorizationUrl; |
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60 | |||
61 | public function __construct() |
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67 | |||
68 | /** |
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69 | * Get Base Url from Paystack config file |
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70 | */ |
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71 | public function setBaseUrl() |
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75 | |||
76 | /** |
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77 | * Get secret key from Paystack config file |
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78 | */ |
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79 | public function setKey() |
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83 | |||
84 | /** |
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85 | * Set options for making the Client request |
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86 | */ |
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87 | private function setRequestOptions() |
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102 | |||
103 | /** |
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104 | * Initiate a payment request to Paystack |
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105 | * @return Paystack |
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106 | */ |
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107 | public function makePaymentRequest() |
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140 | |||
141 | |||
142 | /** |
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143 | * @param string $relativeUrl |
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144 | * @param string $method |
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145 | * @param array $body |
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146 | * @return Paystack |
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147 | * @throws IsNullException |
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148 | */ |
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149 | private function setHttpResponse($relativeUrl, $method, $body = []) |
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162 | |||
163 | /** |
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164 | * Get the authorization url from the callback response |
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165 | * @return Paystack |
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166 | */ |
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167 | public function getAuthorizationUrl() |
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175 | |||
176 | /** |
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177 | * Hit Paystack Gateway to Verify that the transaction is valid |
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178 | */ |
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179 | private function verifyTransactionAtGateway() |
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187 | |||
188 | /** |
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189 | * True or false condition whether the transaction is verified |
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190 | * @return boolean |
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191 | */ |
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192 | public function isTransactionVerificationValid() |
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212 | |||
213 | /** |
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214 | * Get Payment details if the transaction was verified successfully |
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215 | * @return json |
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216 | * @throws PaymentVerificationFailedException |
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217 | */ |
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218 | public function getPaymentData() |
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226 | |||
227 | /** |
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228 | * Fluent method to redirect to Paystack Payment Page |
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229 | */ |
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230 | public function redirectNow() |
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234 | |||
235 | /** |
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236 | * Get Access code from transaction callback respose |
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237 | * @return string |
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238 | */ |
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239 | public function getAccessCode() |
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243 | |||
244 | /** |
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245 | * Generate a Unique Transaction Reference |
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246 | * @return string |
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247 | */ |
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248 | public function genTranxRef() |
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252 | |||
253 | /** |
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254 | * Get all the customers that have made transactions on your platform |
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255 | * @return array |
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256 | */ |
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257 | public function getAllCustomers() |
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263 | |||
264 | /** |
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265 | * Get all the plans that you have on Paystack |
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266 | * @return array |
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267 | */ |
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268 | public function getAllPlans() |
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274 | |||
275 | /** |
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276 | * Get all the transactions that have happened overtime |
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277 | * @return array |
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278 | */ |
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279 | public function getAllTransactions() |
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285 | |||
286 | /** |
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287 | * Get the whole response from a get operation |
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288 | * @return array |
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289 | */ |
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290 | private function getResponse() |
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294 | |||
295 | /** |
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296 | * Get the data response from a get operation |
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297 | * @return array |
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298 | */ |
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299 | private function getData() |
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303 | |||
304 | /** |
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305 | * Create a plan |
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306 | */ |
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307 | View Code Duplication | public function createPlan() |
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323 | |||
324 | /** |
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325 | * Fetch any plan based on its plan id or code |
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326 | * @param $plan_code |
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327 | * @return array |
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328 | */ |
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329 | public function fetchPlan($plan_code) |
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334 | |||
335 | /** |
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336 | * Update any plan's details based on its id or code |
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337 | * @param $plan_code |
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338 | * @return array |
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339 | */ |
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340 | View Code Duplication | public function updatePlan($plan_code) |
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355 | |||
356 | /** |
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357 | * Create a customer |
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358 | */ |
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359 | View Code Duplication | public function createCustomer() |
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373 | |||
374 | /** |
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375 | * Fetch a customer based on id or code |
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376 | * @param $customer_id |
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377 | * @return array |
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378 | */ |
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379 | public function fetchCustomer($customer_id) |
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384 | |||
385 | /** |
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386 | * Update a customer's details based on their id or code |
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387 | * @param $customer_id |
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388 | * @return array |
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389 | */ |
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390 | View Code Duplication | public function updateCustomer($customer_id) |
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404 | |||
405 | /** |
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406 | * Export transactions in .CSV |
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407 | * @return array |
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408 | */ |
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409 | public function exportTransactions() |
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420 | |||
421 | /** |
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422 | * Create a subscription to a plan from a customer. |
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423 | */ |
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424 | View Code Duplication | public function createSubscription() |
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435 | |||
436 | /** |
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437 | * Get all the subscriptions made on Paystack. |
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438 | * |
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439 | * @return array |
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440 | */ |
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441 | public function getAllSubscriptions() |
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447 | |||
448 | /** |
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449 | * Get customer subscriptions |
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450 | * |
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451 | * @param integer $customer_id |
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452 | * @return array |
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453 | */ |
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454 | public function getCustomerSubscriptions($customer_id) |
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460 | |||
461 | /** |
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462 | * Get plan subscriptions |
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463 | * |
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464 | * @param integer $plan_id |
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465 | * @return array |
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466 | */ |
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467 | public function getPlanSubscriptions($plan_id) |
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473 | |||
474 | /** |
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475 | * Enable a subscription using the subscription code and token |
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476 | * @return array |
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477 | */ |
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478 | View Code Duplication | public function enableSubscription() |
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488 | |||
489 | /** |
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490 | * Disable a subscription using the subscription code and token |
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491 | * @return array |
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492 | */ |
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493 | View Code Duplication | public function disableSubscription() |
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503 | |||
504 | /** |
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505 | * Fetch details about a certain subscription |
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506 | * @param mixed $subscription_id |
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507 | * @return array |
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508 | */ |
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509 | public function fetchSubscription($subscription_id) |
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514 | |||
515 | /** |
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516 | * Create pages you can share with users using the returned slug |
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517 | */ |
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518 | View Code Duplication | public function createPage() |
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529 | |||
530 | /** |
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531 | * Fetches all the pages the merchant has |
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532 | * @return array |
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533 | */ |
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534 | public function getAllPages() |
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539 | |||
540 | /** |
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541 | * Fetch details about a certain page using its id or slug |
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542 | * @param mixed $page_id |
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543 | * @return array |
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544 | */ |
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545 | public function fetchPage($page_id) |
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550 | |||
551 | /** |
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552 | * Update the details about a particular page |
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553 | * @param $page_id |
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554 | * @return array |
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555 | */ |
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556 | View Code Duplication | public function updatePage($page_id) |
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567 | } |
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568 |
In PHP it is possible to write to properties without declaring them. For example, the following is perfectly valid PHP code:
Generally, it is a good practice to explictly declare properties to avoid accidental typos and provide IDE auto-completion: