Google providers you huge list of API'S to access the google resources . This resources can be accesses only after passing the authentication layer successfully.Google APIs use the OAuth 2.0 protocol for authentication and authorization. Google supports common OAuth 2.0 scenarios such as those for web server, installed, and client-side applications.
What is OAuth Protocol?
OAuth is an open-source authorization protocol - or set of rules for authorization that allows a third-party application to access a user’s data without the user needing to share login credentials. It purely works on token-based authorization mechanism.
http://www.hakimshabir.blogspot.com/2016/02/using-oauth20-to-access-google-calendar.html
Retrieve Events from GCalendar
Insert Event to GCalendar
What is OAuth Protocol?
OAuth is an open-source authorization protocol - or set of rules for authorization that allows a third-party application to access a user’s data without the user needing to share login credentials. It purely works on token-based authorization mechanism.
http://www.hakimshabir.blogspot.com/2016/02/using-oauth20-to-access-google-calendar.html
JavaScript:
using Google.Apis.Auth.OAuth2;
using Google.Apis.Calendar.v3;
using Google.Apis.Calendar.v3.Data;
using Google.Apis.Services;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
namespace DotNetGoogleCalendarIntegration
{
class Program
{
//I just include calendar scope here because i want to access
//user calendar for event retrieval and insertion
static string[] Scopes = { CalendarService.Scope.Calendar };
static string Applicationname = "Faith Application";
static void Main(string[] args)
{
UserCredential credential;
CalendarService service;
//JSON File created in Google console and added to application folder
using (var stream = new FileStream("..\\..\\googleclient_secret.json",
FileMode.Open, FileAccess.Read))
{
credential = GoogleWebAuthorizationBroker.AuthorizeAsync(
GoogleClientSecrets.Load(stream).Secrets,
Scopes,
Environment.UserName,
CancellationToken.None,
new DatabaseStore(@"Database Server Name", "database username",
"password", "databasename", "tablename")).Result;
//oauth sucks need to get refresh token and save it for persistence and
to avoid popup dialog every time for ACCEPT and DENY
// Console.WriteLine(credential);
}
// Create Calendar Service.
service = new CalendarService(new BaseClientService.Initializer()
{
HttpClientInitializer = credential,
ApplicationName = Applicationname ,
});
// Define parameters of request.
EventsResource.ListRequest request = service.Events.List("primary");
request.TimeMin = DateTime.Now;
request.ShowDeleted = false;
request.SingleEvents = true;
request.MaxResults = 10;
request.OrderBy = EventsResource.ListRequest.OrderByEnum.StartTime;
Console.WriteLine("Upcoming events for Shabir:");
Console.WriteLine("====================================================");
Events events = request.Execute();
if (events.Items.Count > 0)
{
foreach (var eventItem in events.Items)
{
string when = eventItem.Start.DateTime.ToString();
string title = eventItem.Description.ToString();
string organizer = eventItem.Organizer.Email.ToString();
if (String.IsNullOrEmpty(when))
{
when = eventItem.Start.Date;
}
Console.WriteLine("{0}" + Environment.NewLine + "{1}" + Environment.NewLine + "
{2}" + Environment.NewLine + " {3}", eventItem.Summary, when, title, organizer);
Console.WriteLine("------------------------------------------------------");
}
}
else
{
Console.WriteLine("No upcoming events found.");
}
//ADDING EVENT
Event newEvent = new Event();
newEvent.Summary = "Shabir Meeting";
newEvent.Description = "Today going to discuss regarding OAuth Protocol";
newEvent.Start = new EventDateTime();
newEvent.Start.DateTime = DateTime.Now.AddHours(5);
newEvent.End = new EventDateTime();
newEvent.End.DateTime = DateTime.Now.AddHours(8);
service.Events.Insert(newEvent, "primary").ExecuteAsync();
Console.Read();
}
}
}
//Note: In Case you are looking for saving in local file, i mean implementing IFileDataDtore change above function code snippet with
credential = GoogleWebAuthorizationBroker.AuthorizeAsync(
GoogleClientSecrets.Load(stream).Secrets,
Scopes,
Environment.UserName,
CancellationToken.None,
CancellationToken.None,
new FileDataStore(@"D:\CalendarCsharp")).Result;
JavaScript:
//DatabaseStore.cs
using Google.Apis.Json;
using Google.Apis.Util.Store;
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data.SqlClient;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace DotNetGoogleCalendarIntegration
{
public class DatabaseStore : IDataStore
{
//database parameters
readonly string tableName;
readonly string serverName;
readonly string loginName;
readonly string passWord;
readonly string databaseName;
private Boolean _IsConnected { get; set; }
public Boolean connectionAlive { get { return _IsConnected; } }
///
database name</param>
public DatabaseStore(String server, string login, string password, string databasename, string tablename)
{
tableName = tablename;
serverName = server;
loginName = login;
passWord = password;
databaseName = databasename;
SqlConnection myConnection = this.connectdb(); // Opens a connection to the database.
if (_IsConnected)
{
// check if the Table Exists;
try
{
SqlDataReader myReader = null;
SqlCommand myCommand = new SqlCommand("select 1 from GoogleOAuthUser where 1 = 0",myConnection);
myReader = myCommand.ExecuteReader();
while (myReader.Read())
{var hold = myReader["Column1"];}
}
catch
{
// table doesn't exist we create it
SqlCommand myCommand = new SqlCommand("CREATE TABLE [dbo].GoogleOAuthUser( " +
" username [nvarchar](100) NOT NULL," +
" RefreshToken [nvarchar](4000) NOT NULL," +
" Userid [nvarchar](50) NOT NULL" +
" ) ON [PRIMARY]", myConnection);
myCommand.ExecuteNonQuery();
}
}
myConnection.Close();
}
/// Stores the given value for the given key. It creates a new
///file (named <see cref="GenerateStoredKey"/>) in
<typeparam name="T">///type to store in the data store</typeparam>
///
The key</param>
///
The value to store in the data store</param>
public Task StoreAsync<T>(string key, T value)
{
if (string.IsNullOrEmpty(key))
{
throw new ArgumentException("Key MUST have a value");
}
var serialized = NewtonsoftJsonSerializer.Instance.Serialize(value);
SqlConnection myConnection = this.connectdb();
if (!_IsConnected)
{
throw new Exception("Not connected to the database");
}
// Try and find the Row in the DB.
using (SqlCommand command = new SqlCommand
("select Userid from GoogleOAuthUser where UserName = @username", myConnection))
{
command.Parameters.AddWithValue("@username", key);
string hold = null;
SqlDataReader myReader = command.ExecuteReader();
while (myReader.Read())
{
hold = myReader["Userid"].ToString();
}
myReader.Close();
if (hold == null)
{
try
{
// New User we insert it into the database
string insertString = "INSERT INTO [dbo].GoogleOAuthUser (username,RefreshToken,Userid) " +
" VALUES (@key,@value,'1' )";
SqlCommand commandins = new SqlCommand(insertString, myConnection);
commandins.Parameters.AddWithValue("@key", key);
commandins.Parameters.AddWithValue("@value", serialized);
commandins.ExecuteNonQuery();
}
catch (Exception ex)
{
throw new Exception("Error inserting new row: " + ex.Message);
}
}
else
{
try
{
// Existing User We update it
string insertString = "update GoogleOAuthUser " +
" set RefreshToken= @value " +
" where username = @key";
SqlCommand commandins = new SqlCommand(insertString, myConnection);
commandins.Parameters.AddWithValue("@key", key);
commandins.Parameters.AddWithValue("@value", serialized);
commandins.ExecuteNonQuery();
}
catch (Exception ex)
{
throw new Exception("Error updating user: " + ex.Message);
}
}
}
myConnection.Close();
return TaskEx.Delay(0);
}
/// <summary>
/// Deletes the given key. It deletes the <see cref="GenerateStoredKey"/>
/// named file in <see cref="FolderPath"/>.
/// </summary>
///
The key to delete from the data store</param>
public Task DeleteAsync<T>(string key)
{
if (string.IsNullOrEmpty(key))
{
throw new ArgumentException("Key MUST have a value");
}
SqlConnection myConnection = this.connectdb();
if (!_IsConnected)
{
throw new Exception("Not connected to the database");
}
// Deletes the users data.
string deleteString = "delete GoogleOAuthUser from " +
" where username = @key";
SqlCommand commandins = new SqlCommand(deleteString, myConnection);
commandins.Parameters.AddWithValue("@key", key);
commandins.ExecuteNonQuery();
myConnection.Close();
return TaskEx.Delay(0);
}
public Task<T> GetAsync<T>(string key)
{
//Key is the user string sent with AuthorizeAsync
if (string.IsNullOrEmpty(key))
{
throw new ArgumentException("Key MUST have a value");}
TaskCompletionSource<T> tcs = new TaskCompletionSource<T>();
ConnectionStringSettings mySetting = ConfigurationManager.ConnectionStrings["strSqlConnection"];
if (mySetting == null || string.IsNullOrEmpty(mySetting.ConnectionString))
throw new Exception("Fatal error: missing connecting string in web.config file");
string connString = mySetting.ConnectionString;
SqlConnection objConn = new SqlConnection(connString);
objConn.Open();
// Try and find the Row in the DB.
using (SqlCommand command = new SqlCommand("select RefreshToken from GoogleOAuthUser
where UserName = @username;", objConn))
{
command.Parameters.AddWithValue("@username", key);
string RefreshToken = null;
SqlDataReader myReader = command.ExecuteReader();
while (myReader.Read()) {
RefreshToken = myReader["RefreshToken"].ToString();
}
if (RefreshToken == null)
{
// we don't have a record so we request it of the user.
tcs.SetResult(default(T));
}
else
{
try
{
// we have it we use that.
tcs.SetResult(NewtonsoftJsonSerializer.Instance.Deserialize<T>(RefreshToken));
}
catch (Exception ex)
{
tcs.SetException(ex);
}
}
}
return tcs.Task;
}
/// <summary>
/// Clears all values in the data store.
///This method deletes all files in <see cref="FolderPath"/>.
/// </summary>
public Task ClearAsync()
{
SqlConnection myConnection = this.connectdb();
if (!_IsConnected)
{
throw new Exception("Not connected to the database");
}
// Removes all data from the Table.
string truncateString = "truncate table [dbo].GoogleOAuthUser ";
SqlCommand commandins = new SqlCommand(truncateString, myConnection);
commandins.ExecuteNonQuery();
myConnection.Close();
return TaskEx.Delay(0);
}
/// <summary>Creates a unique stored key based on the key and the class type.</summary>
///
The object key</param>
///
The type to store or retrieve</param>
public static string GenerateStoredKey(string key, Type t)
{
return string.Format("{0}-{1}", t.FullName, key);
}
//Handel's creating the connection to the database
private SqlConnection connectdb()
{
ConnectionStringSettings mySetting = ConfigurationManager.ConnectionStrings["strSqlConnection"];
if (mySetting == null || string.IsNullOrEmpty(mySetting.ConnectionString))
throw new Exception("Fatal error: missing connecting string in web.config file");
string connString = mySetting.ConnectionString;
SqlConnection myConnection = null;
try
{
myConnection = new SqlConnection(connString);
try
{
myConnection.Open();
if (myConnection.State == System.Data.ConnectionState.Open)
{
_IsConnected = true;
}
else
{
throw new ArgumentException("Error unable to open connection to the database.");
}
}
catch (Exception ex)
{
throw new ArgumentException("Error opening Connection to the database: " + ex.Message);
}
}
catch (Exception ex)
{
throw new ArgumentException("Error creating Database Connection: " + ex.Message);
}
return myConnection;
}
}
}Retrieve Events from GCalendar
JavaScript:
// // Create Calendar Service.
service = new CalendarService(new BaseClientService.Initializer()
{
HttpClientInitializer = credential,
ApplicationName = ApplicationName,
});
// Define parameters of request.
EventsResource.ListRequest request = service.Events.List("primary");
request.TimeMin = DateTime.Now;
request.ShowDeleted = false;
request.SingleEvents = true;
request.MaxResults = 10;
request.OrderBy = EventsResource.ListRequest.OrderByEnum.StartTime;
Console.WriteLine("Upcoming events for Shabir:");
Console.WriteLine("====================================================");
Events events = request.Execute();
if (events.Items.Count > 0)
{
foreach (var eventItem in events.Items)
{
string when = eventItem.Start.DateTime.ToString();
string title = eventItem.Description.ToString();
string organizer = eventItem.Organizer.Email.ToString();
if (String.IsNullOrEmpty(when))
{
when = eventItem.Start.Date;
}
Console.WriteLine("{0}" + Environment.NewLine + "{1}" + Environment.NewLine + "
{2}" + Environment.NewLine + " {3}", eventItem.Summary, when, title, organizer);
Console.WriteLine("------------------------------------------------------");
}
}
else
{
Console.WriteLine("No upcoming events found.");
}Insert Event to GCalendar
JavaScript:
Event newEvent = new Event();
newEvent.Summary = "Shabir Meeting";
newEvent.Description = "Today going to discuss regarding OAuth Protocol";
newEvent.Start = new EventDateTime();
newEvent.Start.DateTime = DateTime.Now.AddHours(5);
newEvent.End = new EventDateTime();
newEvent.End.DateTime = DateTime.Now.AddHours(8);
service.Events.Insert(newEvent, "primary").ExecuteAsync();
Console.Read();