public static void setUsernameInactive(string username, OnlineChatDBEntities db = null)
{
if (db == null) db = new OnlineChatDBEntities();
User existing_user = db.Users.Where(u => u.username == username).FirstOrDefault();
if(existing_user != null) {
existing_user.is_session_active = false;
db.SaveChanges();
}
}
public ChatModel(int latest_id)
{
//initialize list object
messages = new List<MessageModel>();
//create reference to entity framework object
OnlineChatDBEntities db = new OnlineChatDBEntities();
foreach (Message msg in db.Messages.Where(m => m.msg_id > latest_id).OrderByDescending(m => m.date_posted))
messages.Add(new MessageModel(msg));
active_users = PosterModel.getActiveUsers(db);
}
//on session end, 'log out' user
protected void Session_End(object sender, EventArgs e)
{
if (Session["username"] != null)
{
String inactive_user = Session["username"].ToString();
OnlineChatDBEntities db = new OnlineChatDBEntities();
User current_user = db.Users.Where(u => u.username == inactive_user).FirstOrDefault();
current_user.is_session_active = false;
db.SaveChanges();
}
}
public Boolean isUsernameTaken(string username, OnlineChatDBEntities db = null)
{
if (db == null) db = new OnlineChatDBEntities();
//if the username is currently taken by the active session, return false
if (Session["username"] != null && Session["username"].ToString() == username)
return false;
Boolean taken = db.Users.Count(u => u.username == username && u.is_session_active == true) > 0;
return taken;
}
public ChatModel(int message_count = 12, int message_index = 0)
{
//initialize list object
messages = new List<MessageModel>();
//create reference to entity framework object
OnlineChatDBEntities db = new OnlineChatDBEntities();
foreach (Message msg in db.Messages.OrderByDescending(m => m.date_posted).Skip(message_index).Take(message_count))
messages.Add(new MessageModel(msg));
active_users = PosterModel.getActiveUsers(db);
if (db.Messages.Count() <= message_count + message_index) end_of_messages = true;
}
public ActionResult createMessage(MessageModel message)
{
OnlineChatDBEntities db = new OnlineChatDBEntities();
Message new_message = new Message();
new_message.message_body = message.body;
new_message.date_posted = DateTime.UtcNow;
String username = HttpContext.Session["username"].ToString();
new_message.fk_poster_id = db.Users.Where(u => u.username == username).FirstOrDefault().user_id;
db.Messages.Add(new_message);
db.SaveChanges();
message.id = new_message.msg_id;
message.posted_by.username = username;
message.date_posted = new_message.date_posted;
//message.time_elapsed_since = MessageModel.getDateSince(new_message.date_posted);
return Json(message, JsonRequestBehavior.AllowGet);
}
public static List<PosterModel> getActiveUsers(OnlineChatDBEntities db = null)
{
if (db == null) db = new OnlineChatDBEntities();
List<PosterModel> users = new List<PosterModel>();
foreach (User user in db.Users.Where(u => u.is_session_active == true))
users.Add(new PosterModel(user));
return users;
}
public ActionResult setUsername(string username)
{
//nothing is done if provided username is blank
if (username != "")
{
OnlineChatDBEntities db = new OnlineChatDBEntities();
//if an existing username is taken by session, set it as inactive
if (Session["username"] != null && username != Session["username"].ToString())
setUsernameInactive(Session["username"].ToString());
//if username doesn't currently exist, create it in the database
User target_user = db.Users.Where(u => u.username == username).FirstOrDefault();
if (target_user == null)
{
target_user = new User();
target_user.username = username;
target_user.is_session_active = false;
db.Users.Add(target_user);
}
//check if username is taken, if free, set session variable to username and session trait in db to true
if (!isUsernameTaken(username, db))
{
HttpContext.Session["username"] = username;
target_user.is_session_active = true;
db.SaveChanges();
return Json(username, JsonRequestBehavior.AllowGet);
}
}
return Json(false, JsonRequestBehavior.AllowGet);
}
public ActionResult findNewUpdates(int latest_id)
{
OnlineChatDBEntities db = new OnlineChatDBEntities();
return Json(db.Messages.Count(m => m.msg_id > latest_id) > 0, JsonRequestBehavior.AllowGet);
}
