(Delphi DLL) Get Google Account Info from OAuth2 Access Token

See more Google APIs Examples

In the Google OAuth2 authorization flow, an application can know the email address of the Google account used to authorize access by requesting and processing user information from the Google UserInfo endpoint after obtaining an access token.

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, StringBuilder, JsonObject;

...

procedure TForm1.Button1Click(Sender: TObject);
var
http: HCkHttp;
success: Boolean;
sbResponseBody: HCkStringBuilder;
jResp: HCkJsonObject;
respStatusCode: Integer;
v_sub: PWideChar;
name: PWideChar;
given_name: PWideChar;
family_name: PWideChar;
profile: PWideChar;
picture: PWideChar;
email: PWideChar;
email_verified: Boolean;
locale: PWideChar;

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

http := CkHttp_Create();

// Implements the following CURL command:

// curl -H "Authorization: Bearer YOUR_ACCESS_TOKEN" https://www.googleapis.com/oauth2/v3/userinfo

// Use the following online tool to generate HTTP code from a CURL command
// Convert a cURL Command to HTTP Source Code

// Adds the "Authorization: Bearer YOUR_ACCESS_TOKEN" header.
CkHttp_putAuthToken(http,'YOUR_ACCESS_TOKEN');

sbResponseBody := CkStringBuilder_Create();
success := CkHttp_QuickGetSb(http,'https://www.googleapis.com/oauth2/v3/userinfo',sbResponseBody);
if (success = False) then
  begin
    Memo1.Lines.Add(CkHttp__lastErrorText(http));
    Exit;
  end;

jResp := CkJsonObject_Create();
CkJsonObject_LoadSb(jResp,sbResponseBody);
CkJsonObject_putEmitCompact(jResp,False);

Memo1.Lines.Add('Response Body:');
Memo1.Lines.Add(CkJsonObject__emit(jResp));

respStatusCode := CkHttp_getLastStatus(http);
Memo1.Lines.Add('Response Status Code = ' + IntToStr(respStatusCode));
if (respStatusCode >= 400) then
  begin
    Memo1.Lines.Add('Response Header:');
    Memo1.Lines.Add(CkHttp__lastHeader(http));
    Memo1.Lines.Add('Failed.');
    Exit;
  end;

// Sample JSON response:
// (Sample code for parsing the JSON response is shown below)

// {
//   "sub": "112233445678901234567",
//   "name": "John Doe",
//   "given_name": "John",
//   "family_name": "Doe",
//   "profile": "https://plus.google.com/112233445678901234567",
//   "picture": "https://lh3.googleusercontent.com/a-/AOh14GiU-EXAMPLE",
//   "email": "johndoe@example.com",
//   "email_verified": true,
//   "locale": "en"
// }

// Sample code for parsing the JSON response...
// Use the following online tool to generate parsing code from sample JSON:
// Generate Parsing Code from JSON

v_sub := CkJsonObject__stringOf(jResp,'sub');
name := CkJsonObject__stringOf(jResp,'name');
given_name := CkJsonObject__stringOf(jResp,'given_name');
family_name := CkJsonObject__stringOf(jResp,'family_name');
profile := CkJsonObject__stringOf(jResp,'profile');
picture := CkJsonObject__stringOf(jResp,'picture');
email := CkJsonObject__stringOf(jResp,'email');
email_verified := CkJsonObject_BoolOf(jResp,'email_verified');
locale := CkJsonObject__stringOf(jResp,'locale');

CkHttp_Dispose(http);
CkStringBuilder_Dispose(sbResponseBody);
CkJsonObject_Dispose(jResp);

end;