(Delphi DLL) Get eBay Application Token

This example shows how to request an eBay Application token.

Note: This example requires Chilkat v11.0.0 or greater.

Chilkat for Delphi Downloads Chilkat non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, CkDateTime, FileAccess, HttpResponse, HttpRequest, JsonObject, Http;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
http: HCkHttp;
req: HCkHttpRequest;
endPoint: PWideChar;
resp: HCkHttpResponse;
json: HCkJsonObject;
accessToken: PWideChar;
dtExpire: HCkDateTime;
fac: HCkFileAccess;

begin
success := False;

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

// See the Ebay documentation about Access token types
// Also see the Ebay documentation about client credentials grant flow

http := CkHttp_Create();

// If using the sandbox, the target endpoint will be:
// POST https://api.sandbox.ebay.com/identity/v1/oauth2/token

// If using the production (live) system, the target endpoint will be:
// POST https://api.ebay.com/identity/v1/oauth2/token

// The eBay client_id and client_secret needs to be sent
// in a Basic Authorization  request header, which has this format:
// Authorization: Basic <B64_encoded_oauth_credentials>

// Chilkat takes care of it.  You only need to set the Login = client_id,
// and password = client_secret, and indicate you want "Basic" HTTP Authorization.
CkHttp_putLogin(http,'EBAY_CLIENT_ID');
CkHttp_putPassword(http,'EBAY_CLIENT_SECRET');
CkHttp_putBasicAuth(http,True);

// Let's do the following POST:

//   HTTP method:   POST
//   URL (Sandbox): https://api.sandbox.ebay.com/identity/v1/oauth2/token
// 
//   HTTP headers:
//     Content-Type = application/x-www-form-urlencoded
//     Authorization = Basic <B64-encoded-oauth-credentials>
// 
//   Request body (wrapped for readability):
//     grant_type=client_credentials&
//     redirect_uri=<RuName-value>&
//     scope=<SPACE separated list of scopes>
// 

// Create an HttpRequest object to hold the request params.
req := CkHttpRequest_Create();
CkHttpRequest_putHttpVerb(req,'POST');
CkHttpRequest_AddParam(req,'grant_type','client_credentials');

// The scope query param indicates the access to be provided by the token.
// Multiple scopes can be specified by separating each with a SPACE char.
// See the Ebay OAuth scopes documentation

CkHttpRequest_AddParam(req,'scope','https://api.ebay.com/oauth/api_scope');

endPoint := 'https://api.sandbox.ebay.com/identity/v1/oauth2/token';
CkHttpRequest_putContentType(req,'application/x-www-form-urlencoded');

resp := CkHttpResponse_Create();
success := CkHttp_HttpReq(http,endPoint,req,resp);
if (success = False) then
  begin
    Memo1.Lines.Add(CkHttp__lastErrorText(http));
    Exit;
  end;

// The response is JSON..
json := CkJsonObject_Create();
CkJsonObject_Load(json,CkHttpResponse__bodyStr(resp));
CkJsonObject_putEmitCompact(json,False);

// If the response status code is not 200, then it failed.
Memo1.Lines.Add('Response status code = ' + IntToStr(CkHttpResponse_getStatusCode(resp)));
if (CkHttpResponse_getStatusCode(resp) <> 200) then
  begin
    Memo1.Lines.Add(CkJsonObject__emit(json));
    Memo1.Lines.Add('Failed.');
    Exit;
  end;

// We successfully retrieved an eBay access token.
// The actual access token string can be parsed from the JSON like this:
accessToken := CkJsonObject__stringOf(json,'access_token');

// This application token is only valid for 7200 seconds (2 hours).  We'll want to refresh
// it before it expires.  (There is an online example for that..)
// For now, let's save the JSON to a file for our application to use.

// But before doing that, let's add to the JSON an expiration timestamp
// so we know when to refresh the token.
dtExpire := CkDateTime_Create();
CkDateTime_SetFromCurrentSystemTime(dtExpire);
CkDateTime_AddSeconds(dtExpire,CkJsonObject_IntOf(json,'expires_in'));
CkJsonObject_AppendString(json,'expire_time',CkDateTime__getAsTimestamp(dtExpire,False));

// Persist the JSON to a file.
fac := CkFileAccess_Create();
success := CkFileAccess_WriteEntireTextFile(fac,'qa_data/tokens/ebay.json',CkJsonObject__emit(json),'utf-8',False);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkFileAccess__lastErrorText(fac));
    Memo1.Lines.Add('Failed to save eBay Application token to file.');
    Exit;
  end;

Memo1.Lines.Add(CkJsonObject__emit(json));
Memo1.Lines.Add('Success.');

// The output of this example is:

// 	{ 
// 	  "access_token": "v^1.1#i^1#p^1#I^3#r^0# ... Ajp1BQhJDgAA",
// 	  "token_type": "Application Access Token",
// 	  "expires_in": 7200,
// 	  "refresh_token": "N/A",
// 	  "expire_time": "2017-04-16T14:44:20Z"
// 	}
// 
// 	Success.
// 

CkHttp_Dispose(http);
CkHttpRequest_Dispose(req);
CkHttpResponse_Dispose(resp);
CkJsonObject_Dispose(json);
CkDateTime_Dispose(dtExpire);
CkFileAccess_Dispose(fac);

end;