/// <summary>
/// Subscribes the user specified to the thread specified for notifications. A transaction can be specified to save the information inside the
/// transaction specified. If the user is already subscribed to this thread, nothing is done
/// </summary>
/// <param name="threadId">The thread ID.</param>
/// <param name="userId">The user ID.</param>
/// <param name="adapter">The live adapter with an active transaction. Can be null, in which case a local adapter is used.</param>
/// <returns></returns>
public static async Task <bool> AddThreadToSubscriptionsAsync(int threadId, int userId, IDataAccessAdapter adapter)
{
var localAdapter = adapter == null;
var adapterToUse = adapter ?? new DataAccessAdapter();
try
{
// check if this user is already subscribed to this thread. If not, add a new subscription.
if (await ThreadGuiHelper.GetThreadSubscriptionAsync(threadId, userId, adapterToUse) == null)
{
// user isn't yet subscribed, add the subscription
return(await adapterToUse.SaveEntityAsync(new ThreadSubscriptionEntity { UserID = userId, ThreadID = threadId }).ConfigureAwait(false));
}
// already subscribed, no-op.
return(true);
}
finally
{
if (localAdapter)
{
adapterToUse.Dispose();
}
}
}
/// <summary>
/// Unsubscribes the specified user from the specified thread.
/// </summary>
/// <param name="threadId">The thread ID.</param>
/// <param name="userId">The user ID.</param>
/// <returns>true if delete succeeded, false otherwise</returns>
public static async Task <bool> RemoveSingleSubscriptionAsync(int threadId, int userId)
{
var subscription = await ThreadGuiHelper.GetThreadSubscriptionAsync(threadId, userId);
if (subscription != null)
{
// there's a subscription, delete it
using (var adapter = new DataAccessAdapter())
{
return(await adapter.DeleteEntityAsync(subscription).ConfigureAwait(false));
}
}
return(true);
}
/// <summary>
/// Checks if thread is already subscribed. If so, true is returned otherwise false.
/// </summary>
/// <param name="userId">The user ID.</param>
/// <param name="threadId">The thread ID.</param>
/// <returns>true if the user is already subscribed to this thread otherwise false</returns>
public static async Task <bool> CheckIfThreadIsAlreadySubscribedAsync(int userId, int threadId)
{
return(await ThreadGuiHelper.GetThreadSubscriptionAsync(threadId, userId) != null);
}