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C#

PayPal - Generate Invoice Number

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

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

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C#
bool success = false;

// 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)
Chilkat.JsonObject jsonToken = new Chilkat.JsonObject();
jsonToken.LoadFile("qa_data/tokens/paypal.json");

// Build the Authorization request header field value.
Chilkat.StringBuilder sbAuth = new Chilkat.StringBuilder();
// 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.
Chilkat.Rest rest = new Chilkat.Rest();
bool bAutoReconnect = true;
success = rest.Connect("api.sandbox.paypal.com",443,true,bAutoReconnect);
if (success != true) {
    Debug.WriteLine(rest.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.
Chilkat.StringBuilder sbJsonRequest = new Chilkat.StringBuilder();
Chilkat.StringBuilder sbJsonResponse = new Chilkat.StringBuilder();
success = rest.FullRequestSb("POST","/v1/invoicing/invoices/next-invoice-number",sbJsonRequest,sbJsonResponse);
if (success != true) {
    Debug.WriteLine(rest.LastErrorText);
    return;
}

Chilkat.JsonObject json = new Chilkat.JsonObject();
json.EmitCompact = false;
json.LoadSb(sbJsonResponse);

Debug.WriteLine("Response Status Code = " + Convert.ToString(rest.ResponseStatusCode));

// Did we get a 200 success response?
if (rest.ResponseStatusCode != 200) {
    Debug.WriteLine(json.Emit());
    Debug.WriteLine("Failed.");
    return;
}

// Sample JSON response is shown below.
Debug.WriteLine(json.Emit());
Debug.WriteLine("----------------------");
Debug.WriteLine("Next invoice number: " + json.StringOf("number"));
Debug.WriteLine("success");

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

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