Sample code for 30+ languages & platforms
Pascal (Lazarus/Delphi)

List Events on a Specified Google Calendar

See more Google Calendar Examples

Demonstrates how to fetch the list of events on a particular Google Calendar. The calendar can be referenced by the calendar ID, or by the keyword "primary".

Chilkat Pascal (Lazarus/Delphi) Downloads

Pascal (Lazarus/Delphi)
program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.Http,
  Chilkat.StringBuilder,
  Chilkat.JsonObject;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  jsonToken: TJsonObject;
  http: THttp;
  sbResponse: TStringBuilder;
  json: TJsonObject;
  numEvents: Integer;
  i: Integer;

begin
  success := False;

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

  //  This example uses a previously obtained access token having permission for the 
  //  Google Calendar scope.

  //  In this example, Get Google Calendar OAuth2 Access Token, the access
  //  token was saved to a JSON file.  This example fetches the access token from the file..
  jsonToken := TJsonObject.Create;
  success := jsonToken.LoadFile('qa_data/tokens/googleCalendar.json');
  if (jsonToken.HasMember('access_token') = False) then
    begin
      WriteLn('No access token found.');
      Exit;
    end;
  http := THttp.Create;
  http.AuthToken := jsonToken.StringOf('access_token');

  //  Let's get the primary calendar.  A calendar ID could have be used instead of "primary".
  http.SetUrlVar('calendarId','primary');
  sbResponse := TStringBuilder.Create;
  success := http.QuickGetSb('https://www.googleapis.com/calendar/v3/calendars/{$calendarId}/events',sbResponse);
  if (success <> True) then
    begin
      WriteLn(http.LastErrorText);
      Exit;
    end;

  if (http.LastStatus <> 200) then
    begin
      //  Note: If a 401 unauthorized response is received, it likely means that the OAuth2 access token needs
      //  to be refreshed or re-fetched.
      WriteLn('Error response status: ' + http.LastStatus);
      WriteLn(sbResponse.GetAsString());
      Exit;
    end;

  //  A sample JSON response:
  //  (Code for parsing the Google Calendar events is shown below.)

  //  {
  //   "kind": "calendar#events",
  //   "etag": "\"p32cfpufit76da0g\"",
  //   "summary": "support@chilkatcloud.com",
  //   "updated": "2017-08-10T14:00:27.199Z",
  //   "timeZone": "America/Chicago",
  //   "accessRole": "owner",
  //   "defaultReminders": [
  //    {
  //     "method": "popup",
  //     "minutes": 10
  //    }
  //   ],
  //   "nextSyncToken": "CJj8-fLpzNUCEJj8-fLpzNUCGAU=",
  //   "items": [
  //    {
  //     "kind": "calendar#event",
  //     "etag": "\"3004746854620000\"",
  //     "id": "5jt9fopfg3rr9eftegiuq7gc5k",
  //     "status": "confirmed",
  //     "htmlLink": "https://www.google.com/calendar/event?eid=NWp0OWZvcGZnM3JyOWVmdGVnaXVxN2djNWsgc3VwcG9ydEBjaGlsa2F0Y2xvdWQuY29t",
  //     "created": "2017-08-10T13:57:07.000Z",
  //     "updated": "2017-08-10T13:57:07.310Z",
  //     "summary": "Run 10 miles",
  //     "creator": {
  //      "email": "support@chilkatcloud.com",
  //      "self": true
  //     },
  //     "organizer": {
  //      "email": "support@chilkatcloud.com",
  //      "self": true
  //     },
  //     "start": {
  //      "dateTime": "2017-08-10T12:00:00-05:00"
  //     },
  //     "end": {
  //      "dateTime": "2017-08-10T13:00:00-05:00"
  //     },
  //     "iCalUID": "5jt9fopfg3rr9eftegiuq7gc5k@google.com",
  //     "sequence": 0,
  //     "hangoutLink": "https://plus.google.com/hangouts/_/chilkatcloud.com/support?hceid=c3VwcG9ydEBjaGlsa2F0Y2xvdWQuY29t.5jt9fopfg3rr9eftegiuq7gc5k",
  //     "reminders": {
  //      "useDefault": true
  //     }
  //    },
  //    {
  //     "kind": "calendar#event",
  //     "etag": "\"3004746898118000\"",
  //     "id": "7dvh49vd219r3sq7jdueieu8rc",
  //     "status": "confirmed",
  //     "htmlLink": "https://www.google.com/calendar/event?eid=N2R2aDQ5dmQyMTlyM3NxN2pkdWVpZXU4cmMgc3VwcG9ydEBjaGlsa2F0Y2xvdWQuY29t",
  //     "created": "2017-08-10T13:57:29.000Z",
  //     "updated": "2017-08-10T13:57:29.059Z",
  //     "summary": "Eat Giordano's Pizza",
  //     "creator": {
  //      "email": "support@chilkatcloud.com",
  //      "self": true
  //     },
  //     "organizer": {
  //      "email": "support@chilkatcloud.com",
  //      "self": true
  //     },
  //     "start": {
  //      "dateTime": "2017-08-10T15:00:00-05:00"
  //     },
  //     "end": {
  //      "dateTime": "2017-08-10T16:00:00-05:00"
  //     },
  //     "iCalUID": "7dvh49vd219r3sq7jdueieu8rc@google.com",
  //     "sequence": 0,
  //     "hangoutLink": "https://plus.google.com/hangouts/_/chilkatcloud.com/support?hceid=c3VwcG9ydEBjaGlsa2F0Y2xvdWQuY29t.7dvh49vd219r3sq7jdueieu8rc",
  //     "reminders": {
  //      "useDefault": true
  //     }
  //    },
  //    {
  //     "kind": "calendar#event",
  //     "etag": "\"3004746915224000\"",
  //     "id": "5btd89ljn07bg3tlgpimcaqrro",
  //     "status": "confirmed",
  //     "htmlLink": "https://www.google.com/calendar/event?eid=NWJ0ZDg5bGpuMDdiZzN0bGdwaW1jYXFycm8gc3VwcG9ydEBjaGlsa2F0Y2xvdWQuY29t",
  //     "created": "2017-08-10T13:57:37.000Z",
  //     "updated": "2017-08-10T13:57:37.612Z",
  //     "summary": "Nap",
  //     "creator": {
  //      "email": "support@chilkatcloud.com",
  //      "self": true
  //     },
  //     "organizer": {
  //      "email": "support@chilkatcloud.com",
  //      "self": true
  //     },
  //     "start": {
  //      "dateTime": "2017-08-10T16:30:00-05:00"
  //     },
  //     "end": {
  //      "dateTime": "2017-08-10T17:30:00-05:00"
  //     },
  //     "iCalUID": "5btd89ljn07bg3tlgpimcaqrro@google.com",
  //     "sequence": 0,
  //     "hangoutLink": "https://plus.google.com/hangouts/_/chilkatcloud.com/support?hceid=c3VwcG9ydEBjaGlsa2F0Y2xvdWQuY29t.5btd89ljn07bg3tlgpimcaqrro",
  //     "reminders": {
  //      "useDefault": true
  //     }
  //    }
  //   ]
  //  }
  //  

  json := TJsonObject.Create;
  json.LoadSb(sbResponse);

  numEvents := json.SizeOfArray('items');
  i := 0;
  while i < numEvents do
    begin
      json.I := i;
      WriteLn(json.StringOf('items[i].summary'));
      WriteLn(json.StringOf('items[i].start.dateTime'));
      WriteLn(json.StringOf('items[i].end.dateTime'));
      WriteLn('--');
      i := i + 1;
    end;

  //  Sample output:

  //  Run 10 miles
  //  2017-08-10T12:00:00-05:00
  //  2017-08-10T13:00:00-05:00
  //  --
  //  Eat Giordano's Pizza
  //  2017-08-10T15:00:00-05:00
  //  2017-08-10T16:00:00-05:00
  //  --
  //  Nap
  //  2017-08-10T16:30:00-05:00
  //  2017-08-10T17:30:00-05:00
  //  --
  //  


  jsonToken.Free;
  http.Free;
  sbResponse.Free;
  json.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.