Delphi ActiveX

Get GMail Message Metadata

See more GMail REST API Examples

Demonstrates how to get the metadata for each message in a list of message IDs. Delphi ActiveX

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
success: Integer;
http: TChilkatHttp;
jsonMsgIds: TChilkatJsonObject;
resp: TChilkatHttpResponse;
id: WideString;
i: Integer;
count_i: Integer;
jsonResponse: TChilkatJsonObject;

begin
success := 0;

// 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';

// Let's say we have the following JSON containing a list of message ID's

// {
//   "messages": [
//     {
//       "id": "1712bc1dc22da2a2",
//       "threadId": "1712bc1dc22da2a2"
//     },
//     {
//       "id": "1712b94fa2168040",
//       "threadId": "1712b94fa2168040"
//     },
//     {
//       "id": "1711e4bd96ded05e",
//       "threadId": "1711e4bd96ded05e"
//     },
//     {
//       "id": "1711de0d119e751e",
//       "threadId": "1711de0d119e751e"
//     },
//     {
//       "id": "1711c81a43050f59",
//       "threadId": "1711c81a43050f59"
//     },
//     {
//       "id": "1711c2c1516abce5",
//       "threadId": "1711c2c1516abce5"
//     },
//     {
//       "id": "1711c161e655c915",
//       "threadId": "1711c161e655c915"
//     },
//     {
//       "id": "171199c6e454558c",
//       "threadId": "171199c6e454558c"
//     },
//     {
//       "id": "17119474c8aa248e",
//       "threadId": "17119474c8aa248e"
//     }
//   ],
//   "nextPageToken": "16710921492249671162",
//   "resultSizeEstimate": 309
// }

// Normally your program would have the above JSON in a string variable (obtained from a previous call to get
// a list of message IDs from a GMail mailbox).  In this example, we'll load the JSON from a file.
jsonMsgIds := TChilkatJsonObject.Create(Self);
success := jsonMsgIds.LoadFile('qa_data/json/gmail_message_ids.json');

resp := TChilkatHttpResponse.Create(Self);

i := 0;
count_i := jsonMsgIds.SizeOfArray('messages');
while i < count_i do
  begin
    jsonMsgIds.I := i;
    id := jsonMsgIds.StringOf('messages[i].id');

    // Get the metadata for this message ID.
    http.SetUrlVar('id',id);

    success := http.HttpNoBody('GET','https://www.googleapis.com/gmail/v1/users/userId/messages/{$id}?format=metadata',resp.ControlInterface);
    if (success = 0) 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;

    i := i + 1;
  end;

// Use this online tool to generate parsing code from sample JSON: 
// Generate Parsing Code from JSON
end;