(Delphi ActiveX) Get a List of Message IDs in GMail User's Mailbox

Demonstrates how to get a list of message IDs in a GMail mailbox. The "userId" can be either the user's email address or the special value "me" to indicate the authenticated user.

For more information, see https://developers.google.com/gmail/api/v1/reference/users/messages/list

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

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
http: TChilkatHttp;
resp: IChilkatHttpResponse;
jsonResponse: TChilkatJsonObject;
id: WideString;
threadId: WideString;
resultSizeEstimate: Integer;
i: Integer;
count_i: Integer;

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

http := TChilkatHttp.Create(Self);

http.AuthToken := 'ACCESS_TOKEN';

http.Accept := 'application/json';

resp := http.QuickRequest('GET','https://www.googleapis.com/gmail/v1/users/userId/messages');
if (http.LastMethodSuccess <> 1) then
  begin
    Memo1.Lines.Add(http.LastErrorText);
    Exit;
  end;

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

jsonResponse := TChilkatJsonObject.Create(Self);
jsonResponse.Load(resp.BodyStr);
jsonResponse.EmitCompact := 0;
Memo1.Lines.Add(jsonResponse.Emit());

if (resp.StatusCode <> 200) then
  begin
    Memo1.Lines.Add('Failed.');

    Exit;
  end;

// {
//   "messages": [
//     users.messages Resource
//   ],
//   "nextPageToken": string,
//   "resultSizeEstimate": unsigned integer
// }

resultSizeEstimate := jsonResponse.IntOf('resultSizeEstimate');
i := 0;
count_i := jsonResponse.SizeOfArray('messages');
while i < count_i do
  begin
    jsonResponse.I := i;
    id := jsonResponse.StringOf('messages[i].id');
    threadId := jsonResponse.StringOf('messages[i].threadId');
    i := i + 1;
  end;
end;