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 | * Included the option to pass the payload to this method for situations |
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106 | * when the payload is built on the fly (not passed to the controller from a view) |
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107 | * @return Paystack |
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108 | */ |
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109 | public function makePaymentRequest( $data = null) |
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144 | |||
145 | |||
146 | /** |
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147 | * @param string $relativeUrl |
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148 | * @param string $method |
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149 | * @param array $body |
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150 | * @return Paystack |
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151 | * @throws IsNullException |
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152 | */ |
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153 | private function setHttpResponse($relativeUrl, $method, $body = []) |
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166 | |||
167 | /** |
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168 | * Get the authorization url from the callback response |
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169 | * @return Paystack |
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170 | */ |
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171 | public function getAuthorizationUrl() |
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179 | |||
180 | /** |
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181 | * Get the authorization callback response |
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182 | * In situations where Laravel serves as an backend for a detached UI, the api cannot redirect |
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183 | * and might need to take different actions based on the success or not of the transaction |
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184 | * @return array |
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185 | */ |
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186 | public function getAuthorizationResponse($data) |
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194 | |||
195 | /** |
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196 | * Hit Paystack Gateway to Verify that the transaction is valid |
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197 | */ |
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198 | private function verifyTransactionAtGateway() |
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206 | |||
207 | /** |
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208 | * True or false condition whether the transaction is verified |
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209 | * @return boolean |
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210 | */ |
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211 | public function isTransactionVerificationValid() |
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231 | |||
232 | /** |
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233 | * Get Payment details if the transaction was verified successfully |
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234 | * @return json |
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235 | * @throws PaymentVerificationFailedException |
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236 | */ |
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237 | public function getPaymentData() |
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245 | |||
246 | /** |
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247 | * Fluent method to redirect to Paystack Payment Page |
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248 | */ |
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249 | public function redirectNow() |
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253 | |||
254 | /** |
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255 | * Get Access code from transaction callback respose |
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256 | * @return string |
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257 | */ |
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258 | public function getAccessCode() |
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262 | |||
263 | /** |
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264 | * Generate a Unique Transaction Reference |
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265 | * @return string |
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266 | */ |
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267 | public function genTranxRef() |
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271 | |||
272 | /** |
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273 | * Get all the customers that have made transactions on your platform |
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274 | * @return array |
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275 | */ |
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276 | public function getAllCustomers() |
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282 | |||
283 | /** |
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284 | * Get all the plans that you have on Paystack |
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285 | * @return array |
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286 | */ |
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287 | public function getAllPlans() |
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293 | |||
294 | /** |
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295 | * Get all the transactions that have happened overtime |
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296 | * @return array |
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297 | */ |
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298 | public function getAllTransactions() |
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304 | |||
305 | /** |
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306 | * Get the whole response from a get operation |
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307 | * @return array |
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308 | */ |
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309 | private function getResponse() |
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313 | |||
314 | /** |
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315 | * Get the data response from a get operation |
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316 | * @return array |
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317 | */ |
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318 | private function getData() |
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322 | |||
323 | /** |
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324 | * Create a plan |
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325 | */ |
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326 | View Code Duplication | public function createPlan() |
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342 | |||
343 | /** |
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344 | * Fetch any plan based on its plan id or code |
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345 | * @param $plan_code |
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346 | * @return array |
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347 | */ |
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348 | public function fetchPlan($plan_code) |
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353 | |||
354 | /** |
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355 | * Update any plan's details based on its id or code |
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356 | * @param $plan_code |
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357 | * @return array |
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358 | */ |
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359 | View Code Duplication | public function updatePlan($plan_code) |
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374 | |||
375 | /** |
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376 | * Create a customer |
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377 | */ |
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378 | View Code Duplication | public function createCustomer() |
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392 | |||
393 | /** |
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394 | * Fetch a customer based on id or code |
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395 | * @param $customer_id |
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396 | * @return array |
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397 | */ |
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398 | public function fetchCustomer($customer_id) |
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403 | |||
404 | /** |
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405 | * Update a customer's details based on their id or code |
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406 | * @param $customer_id |
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407 | * @return array |
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408 | */ |
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409 | View Code Duplication | public function updateCustomer($customer_id) |
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423 | |||
424 | /** |
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425 | * Export transactions in .CSV |
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426 | * @return array |
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427 | */ |
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428 | public function exportTransactions() |
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439 | |||
440 | /** |
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441 | * Create a subscription to a plan from a customer. |
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442 | */ |
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443 | View Code Duplication | public function createSubscription() |
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454 | |||
455 | /** |
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456 | * Get all the subscriptions made on Paystack. |
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457 | * |
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458 | * @return array |
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459 | */ |
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460 | public function getAllSubscriptions() |
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466 | |||
467 | /** |
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468 | * Get customer subscriptions |
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469 | * |
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470 | * @param integer $customer_id |
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471 | * @return array |
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472 | */ |
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473 | public function getCustomerSubscriptions($customer_id) |
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479 | |||
480 | /** |
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481 | * Get plan subscriptions |
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482 | * |
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483 | * @param integer $plan_id |
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484 | * @return array |
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485 | */ |
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486 | public function getPlanSubscriptions($plan_id) |
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492 | |||
493 | /** |
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494 | * Enable a subscription using the subscription code and token |
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495 | * @return array |
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496 | */ |
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497 | View Code Duplication | public function enableSubscription() |
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507 | |||
508 | /** |
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509 | * Disable a subscription using the subscription code and token |
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510 | * @return array |
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511 | */ |
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512 | View Code Duplication | public function disableSubscription() |
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522 | |||
523 | /** |
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524 | * Fetch details about a certain subscription |
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525 | * @param mixed $subscription_id |
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526 | * @return array |
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527 | */ |
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528 | public function fetchSubscription($subscription_id) |
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533 | |||
534 | /** |
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535 | * Create pages you can share with users using the returned slug |
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536 | */ |
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537 | View Code Duplication | public function createPage() |
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548 | |||
549 | /** |
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550 | * Fetches all the pages the merchant has |
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551 | * @return array |
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552 | */ |
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553 | public function getAllPages() |
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558 | |||
559 | /** |
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560 | * Fetch details about a certain page using its id or slug |
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561 | * @param mixed $page_id |
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562 | * @return array |
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563 | */ |
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564 | public function fetchPage($page_id) |
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569 | |||
570 | /** |
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571 | * Update the details about a particular page |
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572 | * @param $page_id |
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573 | * @return array |
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574 | */ |
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575 | View Code Duplication | public function updatePage($page_id) |
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586 | } |
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587 |
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: