如何将对象从android应用传递到firebase云功能以完成Paypal付款功能？

Question

I am using firebase cloud functions as serverside for Paypal payment. Documentations are not obvious to understand. when I am trying to send an object from android app to firebase cloud functions, nothing has happened. I think I added it wrong. so how can I pass an object from android app to the function??

  public  void  payout(String PayerID,String paymentId) {
    // Create the arguments to the callable function.
    JSONObject postData = new JSONObject();
    try {
        postData.put("PayerID", PayerID);
        postData.put("paymentId",paymentId);


    } catch (JSONException e) {
        e.printStackTrace();
    }
     mFunctions
            .getHttpsCallable("payout")
            .call(postData)
            .continueWith(new Continuation<HttpsCallableResult, Object>() {
                @Override
                public Object then(@NonNull Task<HttpsCallableResult> task) 
    throws Exception {
                    return null;
                }
            });
}

///////////////////////////////////////////

 exports.payout=functions.https.onRequest((req,res)=>{

const sender_batch_id = Math.random().toString(36).substring(9);
const payReq=JSON.stringify({
        sender_batch_header: {
            sender_batch_id: sender_batch_id,
            email_subject: "You have a nice  payment"
        },
        items: [
            {
                recipient_type: "EMAIL",
                amount: {
                    value: 0.90,
                    currency: "USD"
                },
                receiver: "amrmahmoudM@app.com",
                note: "Thank you very much.",
                sender_item_id: "item_3"
            }
        ]
});
paypal.payout.create(payReq,(error, payout)=>{
    if (error) {
        console.warn(error.res);
        res.status('500').end();
        throw error;

    }else{
        console.info("payout created");
        console.info(payout);
        res.status('200').end();

    }
});
   });
  exports.process = functions.https.onRequest((req, res) => {
const paymentId = req.body.paymentId;
var payerId = {
  payer_id: req.body.PayerID
};
return paypal.payout.execute(paymentId, payerId, (error, payout) => {
  if (error) {
    console.error(error);
  } else {
    if (payout.state === 'approved') {
      console.info('payment completed successfully, description: ', 
        payout.transactions[0].description);
      const ref=admin.firestore().collection("Users").doc(payerId);
       ref.set({'paid': true});


    } else {
      console.warn('payment.state: not approved ?');
              }
  }
}).then(r =>
     console.info('promise: ', r));
  });

Answer 1

The problem comes from the fact that in your Android app you call an HTTPS Callable Function (via mFunctions.getHttpsCallable("payout") ) but your Cloud Function is not an HTTPS Callable Function but a "simple" HTTPS Function.

HTTPS Callable Functions are written like:

exports.payout = functions.https.onCall((data, context) => {
  // ...
});

while HTTPS Functions are written like:

exports.payout = functions.https.onRequest((req,res)=> {
  // ...
})

So you should adapt the code of your Cloud Function according to the documentation: https://firebase.google.com/docs/functions/callable

---

Note that another option could be to write to the database (Real Time database or Firestore) and trigger the Cloud Function with an onWrite or onCreate trigger. The advantage of this approach is that you directly save the information of the payment in the database.