Paypal实现循环扣款（订阅）功能

$param = [
 "name" => "standard_monthly",
 "display_name" => "standard plan",
 "desc" => "standard plan for one month",
 "type" => "regular",
 "frequency" => "month",
 "frequency_interval" => 1,
 "cycles" => 0,
 "amount" => 20,
 "currency" => "usd"
 ];

 //上面的$param例子是个数组，我的实际应用传入的实际是个对象，用户理解下就好。
 public function createplan($param)
 {
 $apicontext = $this->getapicontext();
 $plan = new plan();
 // # basic information
 // fill up the basic information that is required for the plan
 $plan->setname($param->name)
 ->setdescription($param->desc)
 ->settype('infinite');//例子总是设置为无限循环
 // # payment definitions for this billing plan.
 $paymentdefinition = new paymentdefinition();
 // the possible values for such setters are mentioned in the setter method documentation.
 // just open the class file. e.g. lib/paypal/api/paymentdefinition.php and look for setfrequency method.
 // you should be able to see the acceptable values in the comments.
 $paymentdefinition->setname($param->name)
 ->settype($param->type)
 ->setfrequency($param->frequency)
 ->setfrequencyinterval((string)$param->frequency_interval)
 ->setcycles((string)$param->cycles)
 ->setamount(new currency(array('value' => $param->amount, 'currency' => $param->currency)));
 // charge models
 $chargemodel = new chargemodel();
 $chargemodel->settype('tax')
 ->setamount(new currency(array('value' => 0, 'currency' => $param->currency)));
 $returnurl = config('payment.returnurl');
 $merchantpreferences = new merchantpreferences();
 $merchantpreferences->setreturnurl("$returnurl?success=true")
 ->setcancelurl("$returnurl?success=false")
 ->setautobillamount("yes")
 ->setinitialfailamountaction("continue")
 ->setmaxfailattempts("0")
 ->setsetupfee(new currency(array('value' => $param->amount, 'currency' => 'usd')));
 $plan->setpaymentdefinitions(array($paymentdefinition));
 $plan->setmerchantpreferences($merchantpreferences);
 // for sample purposes only.
 $request = clone $plan;
 // ### create plan
 try {
 $output = $plan->create($apicontext);
 } catch (exception $ex) {
 return false;
 }
 $patch = new patch();
 $value = new paypalmodel('{"state":"active"}');
 $patch->setop('replace')
 ->setpath('/')
 ->setvalue($value);
 $patchrequest = new patchrequest();
 $patchrequest->addpatch($patch);
 $output->update($patchrequest, $apicontext);
 return $output;
 }

$param = [
 'id' => 'p-26t36113jt475352643kgihy',//上一步创建plan时生成的id
 'name' => 'standard', 
 'desc' => 'standard plan for one month'
];

 public function createpayment($param)
 {
 $apicontext = $this->getapicontext();
 $agreement = new agreement();
 $agreement->setname($param['name'])
 ->setdescription($param['desc'])
 ->setstartdate(carbon::now()->addmonths(1)->toiso8601string());
 // add plan id
 // please note that the plan id should be only set in this case.
 $plan = new plan();
 $plan->setid($param['id']);
 $agreement->setplan($plan);
 // add payer
 $payer = new payer();
 $payer->setpaymentmethod('paypal');
 $agreement->setpayer($payer);
 // for sample purposes only.
 $request = clone $agreement;
 // ### create agreement
 try {
 // please note that as the agreement has not yet activated, we wont be receiving the id just yet.
 $agreement = $agreement->create($apicontext);
 // ### get redirect url
 // the api response provides the url that you must redirect
 // the buyer to. retrieve the url from the $agreement->getapprovallink()
 // method
 $approvalurl = $agreement->getapprovallink();
 } catch (exception $ex) {
 return "create payment failed, please retry or contact the merchant.";
 }
 return $approvalurl;//跳转到$approvalurl，等待用户同意
 }

 public function onpay($request)
 {
 $apicontext = $this->getapicontext();
 if ($request->has('success') && $request->success == 'true') {
 $token = $request->token;
 $agreement = new paypalapiagreement();
 try {
 $agreement->execute($token, $apicontext);
 } catch(exception $e) {
 return ull;
 return $agreement;
 }
 return null;
 }

 /** 获取交易记录
 * @param $id subscription payment_id
 * @warning 总是获取该subscription的所有记录
 */
 public function transactions($id)
 {
 $apicontext = $this->getapicontext();
 $params = ['start_date' => date('y-m-d', strtotime('-15 years')), 'end_date' => date('y-m-d', strtotime('+5 days'))];
 try {
 $result = agreement::searchtransactions($id, $params, $apicontext);
 } catch(exception $e) {
 log::error("get transactions failed" . $e->getmessage());
 return null;
 }
 return $result->getagreementtransactionlist() ;
 }