Delphi DLL
List Events on a Specified Google Calendar

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".
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Delphi 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
success: Boolean;
jsonToken: HCkJsonObject;
http: HCkHttp;
sbResponse: HCkStringBuilder;
json: HCkJsonObject;
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 := CkJsonObject_Create();
success := CkJsonObject_LoadFile(jsonToken,'qa_data/tokens/googleCalendar.json');
if (CkJsonObject_HasMember(jsonToken,'access_token') = False) then
  begin
    Memo1.Lines.Add('No access token found.');
    Exit;
  end;
http := CkHttp_Create();
CkHttp_putAuthToken(http,CkJsonObject__stringOf(jsonToken,'access_token'));

// Let's get the primary calendar.  A calendar ID could have be used instead of "primary".
CkHttp_SetUrlVar(http,'calendarId','primary');
sbResponse := CkStringBuilder_Create();
success := CkHttp_QuickGetSb(http,'https://www.googleapis.com/calendar/v3/calendars/{$calendarId}/events',sbResponse);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkHttp__lastErrorText(http));
    Exit;
  end;

if (CkHttp_getLastStatus(http) <> 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.
    Memo1.Lines.Add('Error response status: ' + IntToStr(CkHttp_getLastStatus(http)));
    Memo1.Lines.Add(CkStringBuilder__getAsString(sbResponse));
    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 := CkJsonObject_Create();
CkJsonObject_LoadSb(json,sbResponse);

numEvents := CkJsonObject_SizeOfArray(json,'items');
i := 0;
while i < numEvents do
  begin
    CkJsonObject_putI(json,i);
    Memo1.Lines.Add(CkJsonObject__stringOf(json,'items[i].summary'));
    Memo1.Lines.Add(CkJsonObject__stringOf(json,'items[i].start.dateTime'));
    Memo1.Lines.Add(CkJsonObject__stringOf(json,'items[i].end.dateTime'));
    Memo1.Lines.Add('--');
    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
// --
// 

CkJsonObject_Dispose(jsonToken);
CkHttp_Dispose(http);
CkStringBuilder_Dispose(sbResponse);
CkJsonObject_Dispose(json);

end;