/// <summary>
/// Asychronously executes the current collection of registered commands
/// </summary>
/// <remarks>
/// Opens the connection, begins a transaction, initializes all commands, then serially awaits the execution of each command (if async.) Finally commits transaction.
/// Upon failure, transaction is rolled-back. Null commands automatically return 1 for excution.
/// </remarks>
/// <returns>List of integers returned from each registered command</returns>
public async Task <IEnumerable <int> > ExecuteAsync(System.Threading.CancellationToken cancellationToken = default)
{
List <int> retVal = new List <int>();
using (Microsoft.Data.SqlClient.SqlConnection conn = new Microsoft.Data.SqlClient.SqlConnection(_ConnectionString))
{
await conn.OpenAsync();
var trans = (Microsoft.Data.SqlClient.SqlTransaction) await conn.BeginTransactionAsync(cancellationToken);
try
{
int initialized = _Commands.Count;
for (int i = 0; i < initialized; i++)
{
if (_Commands[i] != null)
{
_Commands[i].Initialize(conn, trans);
}
}
for (int i = 0; i < _Commands.Count; i++)
{
if (_Commands[i] != null)
{
// This following line allows for chaining.
// in other words, a executing command can add more commands.
if (i >= initialized)
{
_Commands[i].Initialize(conn, trans);
}
if (_Commands[i] is ICommandAsync)
{
retVal.Add(await((ICommandAsync)_Commands[i]).ExecuteAsync(cancellationToken));
}
else
{
retVal.Add(_Commands[i].Execute());
}
}
else
{
retVal.Add(1);
}
}
await trans.CommitAsync();
}
catch (Exception)
{
try { await trans.RollbackAsync(); } catch (Exception) { }
throw;
}
finally
{
_Commands.Clear();
}
}
return((IEnumerable <int>)retVal);
}
