/// <summary>
/// Primary method for loading more messages when user scrolls to the top of a chat box, aka infinite scrolling.
/// </summary>
/// <returns>
/// A paged list of messages. Client-side will append this new set of messages to the existing set it already has.
/// </returns>
public async Task GetMoreMessages(MemberChatParams memberChatParams)
{
var username = Context.User.GetUsername();
var sender = await _unitOfWork.UserRepository.GetUserByUsernameAsync(username);
var recipient = await _unitOfWork.UserRepository.GetUserByUsernameAsync(memberChatParams.RecipientUsername);
if (recipient == null)
{
throw new HubException("Not found user");
}
var messages = await _unitOfWork.MessageRepository
.GetScrolledMessageThread(Context.User.GetUsername(), memberChatParams.RecipientUsername, memberChatParams);
await Clients.Caller.SendAsync("ReceivedMessageThread", messages);
}
/// <summary>
/// Performs various critical functionality for sending and receiving messages via Signal R.
/// Creates a groupname based on the sender and recipient. Combo of usernames, in alphabetical order.
/// Asynchronously send data to front end that are called in client-side methods
/// The name of the client-side method must match the string passed through in the "SendAsync()"
/// </summary>
public override async Task OnConnectedAsync()
{
var httpContext = Context.GetHttpContext();
// pass in the other user name (via a query string) with the key of user to get it into this variable.
var otherUser = httpContext.Request.Query["user"].ToString();
// initialize the memberChatParams that are needed to get messages from the repo for scrolled pagination.
var memberChatParams = new MemberChatParams {
PageNumber = 1,
PageSize = 10, // SCROLLED PAGE SIZE
RecipientUsername = otherUser
};
// TODO: Consider adding a check here to see if they exist first.
// the group that a pair of users belong to.
var groupName = GetGroupName(Context.User.GetUsername(), otherUser);
await Groups.AddToGroupAsync(Context.ConnectionId, groupName);
var group = await AddToGroup(groupName);
await Clients.Group(groupName).SendAsync("UpdatedGroup", group);
// get messages using GetMessageThread method from repo. (original method, consider removing)
// TODO: Revisit whether this method is necessary anymore. Functionality has been moved to GetScrolledMessageThread()
var messages = await _unitOfWork.MessageRepository
.GetMessageThread(Context.User.GetUsername(), otherUser);
// get messages using GetScrolledMessageThread method from repo (for scrolled pagination)
var messages2 = await _unitOfWork.MessageRepository
.GetScrolledMessageThread(Context.User.GetUsername(), otherUser, memberChatParams);
// check to see if changes in this step. If there are, then save them to the DB here, not within the message repo itself.
if (_unitOfWork.HasChanges())
{
await _unitOfWork.Complete();
}
// send the response back to the caller
await Clients.Caller.SendAsync("ReceiveMessageThread", messages2);
}
/// <summary>
/// Primary method to load a set of messages for a message thread. Used withi infinte scrolling
/// </summary>
/// <param name="currentUsername">The current user's username</param>
/// <param name="recipientUsername">The other user's username</param>
/// <param name="memberChatParams">Params with data for the PagedList settings</param>
/// <returns>
/// A PagedList of messages (used for scrolled apges)
/// </returns>
public async Task <IEnumerable <MessageDto> > GetScrolledMessageThread(string currentUsername, string recipientUsername, MemberChatParams memberChatParams)
{
// store the query. Filter messagse for these users. Include photos. Order descending by MessageSent date
var query = _context.Messages
.Include(u => u.Sender).ThenInclude(p => p.Photos)
.Include(u => u.Recipient).ThenInclude(p => p.Photos)
.Where(m => m.Recipient.UserName == currentUsername && m.RecipientDeleted == false &&
m.Sender.UserName == recipientUsername ||
m.Recipient.UserName == recipientUsername &&
m.Sender.UserName == currentUsername && m.SenderDeleted == false
)
.OrderByDescending(m => m.MessageSent)
.AsQueryable();
// from the list of messages, determine if the current user has unread messages.
var unreadMessages = query.Where(m => m.DateRead == null && m.Recipient.UserName == currentUsername).ToList();
// then mark those unread messages as read
if (unreadMessages.Any())
{
foreach (var message in unreadMessages)
{
message.DateRead = DateTime.UtcNow;
}
// save to DB (slight deviation from Unit of Work framework. But need for now if we still want to return a list of MessageDtos)
// alternative is to have this method return a list of type Message, instead of the MessageDto.
await _context.SaveChangesAsync();
}
return(await PagedList <MessageDto> .CreateScrolledAsync(query.ProjectTo <MessageDto>(_mapper.ConfigurationProvider).AsNoTracking(),
memberChatParams.PageNumber, memberChatParams.PageSize));
}
