Dart

PayPal - Generate Invoice Number

See more PayPal Examples

Generates the next invoice number that is available to the user.

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

Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // 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)
  final jsonToken = CkJsonObject();
  jsonToken.loadFile('qa_data/tokens/paypal.json');

  // Build the Authorization request header field value.
  final sbAuth = CkStringBuilder();
  // 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.
  final rest = CkRest();
  final bAutoReconnect = true;
  try {
    rest.connect('api.sandbox.paypal.com', 443, true, bAutoReconnect);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    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..
  // ----------------------------------------------------------------------------------------------

  // Clear the REST object of any headers or query params from previous requests.
  rest.clearAllHeaders();
  rest.clearAllQueryParams();

  rest.addHeader('Authorization', sbAuth.getAsString());

  // Send the POST request with an emtpy body and get the JSON response.
  final sbJsonRequest = CkStringBuilder();
  final sbJsonResponse = CkStringBuilder();
  try {
    rest.fullRequestSb('POST', '/v1/invoicing/invoices/next-invoice-number', sbJsonRequest, sbJsonResponse);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  final json = CkJsonObject();
  json.emitCompact = false;
  json.loadSb(sbJsonResponse);

  print('Response Status Code = ${rest.responseStatusCode}');

  // Did we get a 200 success response?
  if (rest.responseStatusCode != 200) {
    print(json.emit());
    print('Failed.');
    return;
  }

  // Sample JSON response is shown below.
  print(json.emit());
  print('----------------------');
  print('Next invoice number: ${json.stringOf('number')}');
  print('success');

  // ------------------------------------------------
  // A sample JSON response:

  // 	{ 
  // 	  "number": "0003"
  // 	}
}