How to redirect to URL from webhook

Question

I have developed a Go app. A webhook has been integrated. I have been successful in getting the payload (JSON format) from the webhook. However, I can't seem to do a redirect.

Step 1: User make payment at page /live.

Step 2: Upon successful payment, my payment processing company send a POST request to my webhook (/paymentsucess). payment function is called. In payment(), I was able to decode the JSON data that was POST to /paymentsucess and fmt.Println accordingly.

http.HandleFunc("/paymentsuccess", payment)

Now in Step 3, I want to redirect the user (which is still seeing /live) to a page (/thankyou) on successful payment. In the JSON posted to the webhook, there is a payment status field. I was able to do a if condition to check that this field has value "success". In such case, fmt.Println("redirecting to thank you"). This is all good. Then in the next line (inside payment() function), I added the below

http.Redirect(w, r, "/thankyou", http.StatusSeeOther)

I was expecting the current client page (which is still at /live) to redirect to /thankyou. But this is not happening.

How should one handle webhook redirects?

UPDATE When the webhook post successfully to payment(), I receive the below response and request

response

&{0xc00029c1e0 0xc0002a0700 0xc000386300 0x1120e20 false false false false 0 {0 0} 0xc000386200 {0xc0003a67e0 map[] false false} map[] false 0 -1 0 false false [] 0 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0] [0 0 0 0 0 0 0 0 0 0] [0 0 0] 0xc0003481c0 0}

request

&{POST /paymentsuccess HTTP/1.1 1 1 map[Accept:[*/*] Accept-Encoding:[gzip] Content-Length:[3162] Content-Type:[application/json] User-Agent:[Omise/2019-05-29] X-Datadog-Parent-Id:[6096593905335487199] X-Datadog-Sampling-Priority:[1] X-Datadog-Trace-Id:[8016780258334486542] X-Forwarded-For:[52.74.199.175] X-Forwarded-Proto:[https]] 0xc000386300 <nil> 3162 [] false d4e7c3fca000.ngrok.io:443 map[] map[] <nil> map[] [::1]:60999 /paymentsuccess <nil> <nil> <nil> 0xc000386340}

UPDATE 2 Thanks to @gipsy I as able to implement the steps he suggested. Right up to Step 4. I have a goroutine who poll query mysql database every two seconds to check for payment status. Once so, I was able to fmt.Println accordingly. So that confirms that I can confirm payment. BUT... I have trouble redirecting the current client page (user is at /live)...

func startPolling1(ShopName, SourceID, Status string) (string, bool) {
    for {
        time.Sleep(2 * time.Second)
        Amount, Result := queryDBForPaymentSuccess(ShopName, SourceID, Status)
        if Result == true {
            fmt.Println("found result")
            fmt.Println("no more polling")

            //HOW DO I DO A REDIRECT HERE? http.Redirect won't work because of error "superfluous response.WriteHeader call"

            break
        }
    }
    return Amount, Result
}

func livemode(res http.ResponseWriter, req *http.Request) {
if !alreadyLoggedIn(req) {
        http.Redirect(res, req, "/", http.StatusSeeOther)
        return
    }
    Shop = getUser(res, req)

    if req.Method == http.MethodPost {
       //Some codes here
       go startPolling1(Shop.Shopname, Charge.Source.ID, "successful")
       //Some codes here
     }
   }
 tpl.ExecuteTemplate(res, "golive.html", data1)
}

What is happening? Can you show some actual debug output? I.e. if you do a query with curl -v, what output do you see? — Flimzy
@Flimzy I'm not sure. I am a new programmer so is still very amateur. I have updated my post with the response and request. The POST request to /paymentsuccess is good. But I just can't redirect my user to /thankyou. I was thinking, if the right way is to set my webhook to be /live? — Ewan Sou

gipsy gipsy · Accepted Answer · 2020-12-12T18:13:47

First of all the web-hook request coming to your server is totally independent from the request you get from your user. So a redirect you try in the web-hook handle is not going to work

I think there could be many way to handle this. One way could be:

Let the user submit the payment at /live( which you are doing)
As part of completing the payment set status for that payment request in your db , say pending.
When the web-hook arrives update the status to completed.
Keep polling for the payment status from /live and when it see completed redirect user to wherever you want.
You could use an ajax call to your server for the status check.

How to redirect to URL from webhook

1 Answers