(Delphi DLL) 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 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, HttpResponse, JsonObject;

...

procedure TForm1.Button1Click(Sender: TObject);
var
http: HCkHttp;
resp: HCkHttpResponse;
jsonResponse: HCkJsonObject;
id: PWideChar;
threadId: PWideChar;
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 := CkHttp_Create();

CkHttp_putAuthToken(http,'ACCESS_TOKEN');

CkHttp_putAccept(http,'application/json');

resp := CkHttp_QuickRequest(http,'GET','https://www.googleapis.com/gmail/v1/users/userId/messages');
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)));

jsonResponse := CkJsonObject_Create();
CkJsonObject_Load(jsonResponse,CkHttpResponse__bodyStr(resp));
CkJsonObject_putEmitCompact(jsonResponse,False);
Memo1.Lines.Add(CkJsonObject__emit(jsonResponse));

if (CkHttpResponse_getStatusCode(resp) <> 200) then
  begin
    Memo1.Lines.Add('Failed.');
    CkHttpResponse_Dispose(resp);
    Exit;
  end;

CkHttpResponse_Dispose(resp);

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

resultSizeEstimate := CkJsonObject_IntOf(jsonResponse,'resultSizeEstimate');
i := 0;
count_i := CkJsonObject_SizeOfArray(jsonResponse,'messages');
while i < count_i do
  begin
    CkJsonObject_putI(jsonResponse,i);
    id := CkJsonObject__stringOf(jsonResponse,'messages[i].id');
    threadId := CkJsonObject__stringOf(jsonResponse,'messages[i].threadId');
    i := i + 1;
  end;

CkHttp_Dispose(http);
CkJsonObject_Dispose(jsonResponse);

end;