(Delphi DLL) Twitter - Application Only Authentication

Demonstrates how to get a Twitter OAuth2 token for application-only authentication.

This example is deprecated and no longer valid.

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, Http, HttpRequest, HttpResponse, JsonObject;

...

procedure TForm1.Button1Click(Sender: TObject);
var
consumerKey: PWideChar;
consumerSecret: PWideChar;
http: HCkHttp;
req: HCkHttpRequest;
resp: HCkHttpResponse;
json: HCkJsonObject;

begin
// It requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// Note: Define your Twitter apps at https://apps.twitter.com/

// We're going to send an HTTPS POST that looks like this:

// POST /oauth2/token HTTP/1.1
// Host: api.twitter.com
// User-Agent: My Twitter App v1.0.23
// Authorization: Basic eHZ6MWV2RlM0d0VFUFRHRUZQSEJvZzpMOHFxOVBaeVJn
//                      NmllS0dFS2hab2xHQzB2SldMdzhpRUo4OERSZHlPZw==
// Content-Type: application/x-www-form-urlencoded;charset=UTF-8
// Content-Length: 29
// Accept-Encoding: gzip
// 
// grant_type=client_credentials

// Update these values with your consumer key and secret (also known as API key and API secret).
consumerKey := 'TWITTER_CONSUMER_KEY';
consumerSecret := 'TWITTER_CONSUMER_SECRET';

http := CkHttp_Create();

CkHttp_putBasicAuth(http,True);
CkHttp_putLogin(http,consumerKey);
CkHttp_putPassword(http,consumerSecret);

req := CkHttpRequest_Create();
CkHttpRequest_AddParam(req,'grant_type','client_credentials');

resp := CkHttp_PostUrlEncoded(http,'https://api.twitter.com/oauth2/token',req);
if (CkHttp_getLastMethodSuccess(http) <> True) then
  begin
    Memo1.Lines.Add(CkHttp__lastErrorText(http));
    Exit;
  end;

Memo1.Lines.Add('Response Status Code: ' + IntToStr(CkHttpResponse_getStatusCode(resp)));

if (CkHttpResponse_getStatusCode(resp) <> 200) then
  begin
    Memo1.Lines.Add('Expected a 200 response status code for success.');
    Memo1.Lines.Add(CkHttpResponse__bodyStr(resp));
    Exit;
  end;

// We should get a JSON response like this:

// {
//     "token_type":"bearer",
//     "access_token":"..."
// }

json := CkJsonObject_Create();
CkJsonObject_Load(json,CkHttpResponse__bodyStr(resp));

Memo1.Lines.Add('Access token = ' + CkJsonObject__stringOf(json,'access_token'));

CkHttpResponse_Dispose(resp);

CkHttp_Dispose(http);
CkHttpRequest_Dispose(req);
CkJsonObject_Dispose(json);

end;