Classic ASP
PayPal - Generate Invoice Number

Generates the next invoice number that is available to the user.
Note: This example requires Chilkat v9.5.0.65 or greater.
Chilkat Classic ASP Downloads

Classic ASP
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<%
success = 0

' 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)
set jsonToken = Server.CreateObject("Chilkat.JsonObject")
success = jsonToken.LoadFile("qa_data/tokens/paypal.json")

' Build the Authorization request header field value.
set sbAuth = Server.CreateObject("Chilkat.StringBuilder")
' token_type should be "Bearer"
success = sbAuth.Append(jsonToken.StringOf("token_type"))
success = sbAuth.Append(" ")
success = 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.
set rest = Server.CreateObject("Chilkat.Rest")
bAutoReconnect = 1
success = rest.Connect("api.sandbox.paypal.com",443,1,bAutoReconnect)
If (success <> 1) Then
    Response.Write "<pre>" & Server.HTMLEncode( rest.LastErrorText) & "</pre>"
    Response.End
End If

' ----------------------------------------------------------------------------------------------
' 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.
success = rest.ClearAllHeaders()
success = rest.ClearAllQueryParams()

success = rest.AddHeader("Authorization",sbAuth.GetAsString())

' Send the POST request with an emtpy body and get the JSON response.
set sbJsonRequest = Server.CreateObject("Chilkat.StringBuilder")
set sbJsonResponse = Server.CreateObject("Chilkat.StringBuilder")
success = rest.FullRequestSb("POST","/v1/invoicing/invoices/next-invoice-number",sbJsonRequest,sbJsonResponse)
If (success <> 1) Then
    Response.Write "<pre>" & Server.HTMLEncode( rest.LastErrorText) & "</pre>"
    Response.End
End If

set json = Server.CreateObject("Chilkat.JsonObject")
json.EmitCompact = 0
success = json.LoadSb(sbJsonResponse)

Response.Write "<pre>" & Server.HTMLEncode( "Response Status Code = " & rest.ResponseStatusCode) & "</pre>"

' Did we get a 200 success response?
If (rest.ResponseStatusCode <> 200) Then
    Response.Write "<pre>" & Server.HTMLEncode( json.Emit()) & "</pre>"
    Response.Write "<pre>" & Server.HTMLEncode( "Failed.") & "</pre>"
    Response.End
End If

' Sample JSON response is shown below.
Response.Write "<pre>" & Server.HTMLEncode( json.Emit()) & "</pre>"
Response.Write "<pre>" & Server.HTMLEncode( "----------------------") & "</pre>"
Response.Write "<pre>" & Server.HTMLEncode( "Next invoice number: " & json.StringOf("number")) & "</pre>"
Response.Write "<pre>" & Server.HTMLEncode( "success") & "</pre>"

' ------------------------------------------------
' A sample JSON response:

' 	{ 
' 	  "number": "0003"
' 	}

%>
</body>
</html>