[PHP] How to integrated Paypal with PHP

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Today topic I will show you how to integrated paypal with PHP

PayPal Holdings, Inc. is an American company operating a worldwide online payments system that supports online money transfers and serves as an electronic alternative to traditional paper methods like checks and money orders

These are paypal url helpful link: https://developer.paypal.com/developer/applications/

First, you have to recreate a App information:
Client Id and Client Credentials

If you running above api got below message, that mean you run api had succeed

How to pass the params:
Let take a look on postman demo
Authorization: username (client id, client credentials)

Headers.

Body: grant_type:

// php code here

// Author: Zidane (huuvi168@gmail.com)
// "intent": "order" 用途，如果商戶有過渡期，一般會onhold 客人信用卡信用額，到佐貨品發貨時扣除；或客人在過渡期期間申請退款，直接release 信用額，避免手續費
// 如果"intent": "sale"， 直接扣款，無佐中間onhold
 public function create_paypal_payment($invoice_number, $price, $description, $access_token, $currency = 'HKD', $role)  {

  $curl = curl_init();
  curl_setopt_array($curl, array(
   CURLOPT_URL => Environment::read('paypal.url_create_payment'),  
   CURLOPT_RETURNTRANSFER => true,
   CURLOPT_ENCODING => "",
   CURLOPT_MAXREDIRS => 10,
   CURLOPT_TIMEOUT => 30,
   CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
   CURLOPT_CUSTOMREQUEST => "POST",
  ));

 
  $intent = "sale";
  $return_url = Environment::read('paypal.url_return_teacher');
  $cancel_url = Environment::read('paypal.url_cancel');
 
  if ($role == Environment::read('member.student')) {
   $return_url = Environment::read('paypal.url_return_student');
   $cancel_url = Environment::read('paypal.url_cancel'); 
   $intent = 'authorize'; // need approve by teacher
   
  }

  $params = array(
   
   "intent" => $intent,
   'payer' => array(
    'payment_method' => 'paypal',
   ),
   'redirect_urls' => array(
    "return_url" => $this->get_current_host_server_name() . $return_url, // "http://localhost/masterx/api/payment/payments/get_info_from_return_url_paypal.json", // get payer_id from this link
    "cancel_url" => $this->get_current_host_server_name() . $cancel_url,  // "https://youtu.be/FigKDd_yhFo"
   ),
   'transactions' => array(
    array(
     'invoice_number'  => $invoice_number, // must be different, because same invoice which paid, so the paypal will block it (Duplicate invoice Id detected.).
     'amount' => array(
      'total'   => $price,
      'currency'   => $currency,
     ),
     'description'  => $description,
    )
   ),
  );

  //save transaction for later call

  curl_setopt($curl, CURLOPT_POSTFIELDS, json_encode($params));
  curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, true);
  curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, 2);

  if (!empty($access_token) && !is_null($access_token)) {
   curl_setopt($curl, CURLOPT_HTTPHEADER, 
    array(      // use this so we MUST post to header (postman)
     "authorization: Bearer " . $access_token,
     "cache-control: no-cache",
     "content-type: application/json"
    )
   );
  } else {
   curl_setopt($curl, CURLOPT_HTTPHEADER, 
    array(      // use this so we MUST post to header (postman)
     "accept: application/json",
     "accept-language: en_US",
     "authorization: Basic ".  base64_encode($this->client_id . ":" . $this->secret),
     "cache-control: no-cache",
     "content-type: application/x-www-form-urlencoded"
    )
   );
  }

  $response = curl_exec($curl);
  $err = curl_error($curl);
  curl_close($curl);
  $result = array();

  if ($err) {
   $result = array(
    'err' => $err,
   );

  } else {
   $result = json_decode($response, true);
  }
  return $result;
 }

Hope you solved your problem,
Any feedback or question, leave your comment, we can discuss about it~
Zidane