(Go) PayPal - Cancel Sent Invoice

Cancels a sent invoice, by ID, and, optionally, sends a notification about the cancellation to the payer, merchant, and Cc: emails.

Note: This example requires Chilkat v9.5.0.65 or greater.

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    // Note: Requires Chilkat v9.5.0.65 or greater.

    // This requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // Load our previously obtained access token. (see PayPal OAuth2 Access Token)
    jsonToken := chilkat.NewJsonObject()
    jsonToken.LoadFile("qa_data/tokens/paypal.json")

    // Build the Authorization request header field value.
    sbAuth := chilkat.NewStringBuilder()
    // token_type should be "Bearer"
    sbAuth.Append(*jsonToken.StringOf("token_type"))
    sbAuth.Append(" ")
    sbAuth.Append(*jsonToken.StringOf("access_token"))

    // Make the initial connection.
    // A single REST object, once connected, can be used for many PayPal REST API calls.
    // The auto-reconnect indicates that if the already-established HTTPS connection is closed,
    // then it will be automatically re-established as needed.
    rest := chilkat.NewRest()
    bAutoReconnect := true
    success := rest.Connect("api.sandbox.paypal.com",443,true,bAutoReconnect)
    if success != true {
        fmt.Println(rest.LastErrorText())
        jsonToken.DisposeJsonObject()
        sbAuth.DisposeStringBuilder()
        rest.DisposeRest()
        return
    }

    // ----------------------------------------------------------------------------------------------
    // The code above this comment could be placed inside a function/subroutine within the application
    // because the connection does not need to be made for every request.  Once the connection is made
    // the app may send many requests..
    // ----------------------------------------------------------------------------------------------

    // Build the JSON request body containing the reminder information:
    json := chilkat.NewJsonObject()
    json.SetEmitCompact(false)
    json.UpdateString("subject","Past due")
    json.UpdateString("note","Canceling invoice")
    json.UpdateBool("send_to_merchant",true)
    json.UpdateBool("send_to_payer",true)
    fmt.Println(*json.Emit())

    // The JSON created by the above code:

    // 	{ 
    // 	  "subject": "Past due",
    // 	  "note": "Canceling invoice",
    // 	  "send_to_merchant": true,
    // 	  "send_to_payer": true
    // 	}

    // Build a path using a previously-sent invoice ID.
    sbPath := chilkat.NewStringBuilder()
    sbPath.Append("/v1/invoicing/invoices/invoice_id/cancel")
    numReplacements := sbPath.Replace("invoice_id","INV2-XPWZ-NUTQ-LNWB-P8NC")

    json.SetEmitCompact(true)
    sbRequestBody := chilkat.NewStringBuilder()
    sbResponseBody := chilkat.NewStringBuilder()

    rest.AddHeader("Content-Type","application/json")
    rest.AddHeader("Authorization",*sbAuth.GetAsString())
    json.EmitSb(sbRequestBody)

    success = rest.FullRequestSb("POST",*sbPath.GetAsString(),sbRequestBody,sbResponseBody)
    if success != true {
        fmt.Println(rest.LastErrorText())
        jsonToken.DisposeJsonObject()
        sbAuth.DisposeStringBuilder()
        rest.DisposeRest()
        json.DisposeJsonObject()
        sbPath.DisposeStringBuilder()
        sbRequestBody.DisposeStringBuilder()
        sbResponseBody.DisposeStringBuilder()
        return
    }

    fmt.Println("Response Status Code = ", rest.ResponseStatusCode())

    // In our testing, we received a 204 response, which is a success HTTP response code, but 
    // differs from the PayPal REST API reference documentation, which states that a 202 response
    // is expected.  I suspect an error in the PayPal documentation, or in the PayPal responder.
    // Check for either 202 or 204..
    // Did we get a 202 accepted response?
    if (rest.ResponseStatusCode() != 202) && (rest.ResponseStatusCode() != 204) {
        fmt.Println(*sbResponseBody.GetAsString())
        fmt.Println("Failed.")
        jsonToken.DisposeJsonObject()
        sbAuth.DisposeStringBuilder()
        rest.DisposeRest()
        json.DisposeJsonObject()
        sbPath.DisposeStringBuilder()
        sbRequestBody.DisposeStringBuilder()
        sbResponseBody.DisposeStringBuilder()
        return
    }

    // The 202/204 response should be empty.  (Again, our experience differs from the online PayPal documentation..)
    fmt.Println("Success.")

    jsonToken.DisposeJsonObject()
    sbAuth.DisposeStringBuilder()
    rest.DisposeRest()
    json.DisposeJsonObject()
    sbPath.DisposeStringBuilder()
    sbRequestBody.DisposeStringBuilder()
    sbResponseBody.DisposeStringBuilder()