(MFC) 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.

Chilkat C/C++ Library Downloads MS Visual C/C++ Libs

See Also: Using MFC CString in Chilkat

#include <CkJsonObject.h>
#include <CkStringBuilder.h>
#include <CkRest.h>

void ChilkatSample(void)
    {
    CkString strOut;

    // 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)
    CkJsonObject jsonToken;
    jsonToken.LoadFile("qa_data/tokens/paypal.json");

    // Build the Authorization request header field value.
    CkStringBuilder sbAuth;
    // 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.
    CkRest rest;
    bool bAutoReconnect = true;
    bool success = rest.Connect("api.sandbox.paypal.com",443,true,bAutoReconnect);
    if (success != true) {
        strOut.append(rest.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        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:
    CkJsonObject json;
    json.put_EmitCompact(false);
    json.UpdateString("subject","Past due");
    json.UpdateString("note","Canceling invoice");
    json.UpdateBool("send_to_merchant",true);
    json.UpdateBool("send_to_payer",true);
    strOut.append(json.emit());
    strOut.append("\r\n");

    // 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.
    CkStringBuilder sbPath;
    sbPath.Append("/v1/invoicing/invoices/invoice_id/cancel");
    int numReplacements = sbPath.Replace("invoice_id","INV2-XPWZ-NUTQ-LNWB-P8NC");

    json.put_EmitCompact(true);
    CkStringBuilder sbRequestBody;
    CkStringBuilder sbResponseBody;

    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) {
        strOut.append(rest.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    strOut.append("Response Status Code = ");
    strOut.appendInt(rest.get_ResponseStatusCode());
    strOut.append("\r\n");

    // 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.get_ResponseStatusCode() != 202) && (rest.get_ResponseStatusCode() != 204)) {
        strOut.append(sbResponseBody.getAsString());
        strOut.append("\r\n");
        strOut.append("Failed.");
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // The 202/204 response should be empty.  (Again, our experience differs from the online PayPal documentation..)
    strOut.append("Success.");
    strOut.append("\r\n");


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }