private static async Task ViewModelExecute(IExecution sender,
List <IBaseOperation> operations,
Func <Task> notifyOfActivity = null,
Func <Task> notifyActivityFinished = null,
Func <Exception, Task <bool> > handleUnhandledException = null,
Func <Task> handleTimeout = null,
int timeoutMilliseconds = 0,
IApplicationInsights insights = null,
string name = "",
object parameter = null)
{
// If currently executing, ignore the latest request
lock (sender)
{
if (!_status.ContainsKey(sender))
{
_status.Add(sender, true);
}
else if (_status[sender])
{
return;
}
else
{
_status[sender] = true;
}
}
if (sender == null)
{
throw new Exception($"The {nameof(IExecution)} sender can not be null");
}
if (notifyOfActivity == null)
{
throw new Exception($"{nameof(notifyOfActivity)} is null: You must notify the user that something is happening");
}
await notifyOfActivity();
// Background thread
var insightTask = Task.Run(() =>
{
try
{
if (insights != null)
{
insights.TrackEvent(name, $"User activated {name}");
}
}
catch (Exception ex)
{
Debug.WriteLine($"insights.TrackEvent({name}) {ex.Message}");
}
}).ConfigureAwait(false);
await Task.Run(async() =>
{
sender.Result = null;
List <Func <Task> > rollbacks = new List <Func <Task> >();
bool transactionRunning = false;
// Setup Cancellation of Tasks if long running
var task = new CancellationTokenSource();
var exceptionState = new PropertyArgs()
{
Value = false
};
if (timeoutMilliseconds > 0)
{
if (handleTimeout != null)
{
task.Token.Register(async(state) => { if (!(bool)((PropertyArgs)state).Value)
{
await handleTimeout();
}
}, exceptionState);
}
else if (handleUnhandledException != null)
{
task.Token.Register(async(state) => { if (!(bool)((PropertyArgs)state).Value)
{
await handleUnhandledException(new TimeoutException());
}
}, exceptionState);
}
else
{
throw new Exception($"You must specify either {nameof(handleTimeout)} or {nameof(handleUnhandledException)} to handle a timeout.");
}
task.CancelAfter(timeoutMilliseconds);
}
IList <IResult> results = new List <IResult>();
try
{
// Transaction Block
transactionRunning = true;
foreach (var operation in operations)
{
if (operation.Rollback != null)
{
rollbacks.Add(operation.Rollback);
}
if (operation is IOperation || operation is IChainedOperation)
{
var op = operation as IOperation;
if (op.Function != null)
{
try
{
await op.Function(results, parameter, task.Token);
}
catch
{
exceptionState.Value = true; // Stops registered cancel function from running, since this is exception not timeout
task?.Cancel(); // Cancel all tasks
throw; // Go to unhandled exception
}
}
}
else
{
var op = operation as ISingleOperation;
try
{
if (op.Function != null)
{
var resultList = await op.Function(parameter, task.Token);
if (resultList != null)
{
foreach (var result in resultList)
{
results.Add(result);
}
}
}
}
catch
{
exceptionState.Value = true; // Stops registered cancel function from running, since this is exception not timeout
task?.Cancel(); // Cancel all tasks
throw; // Go to unhandled exception
}
}
if (!operation.ChainedRollback)
{
rollbacks.Remove(operation.Rollback);
}
}
rollbacks.Clear();
transactionRunning = false;
// End of Transaction Block
}
catch (Exception e)
{
if (handleUnhandledException == null)
{
throw;
}
var handled = await handleUnhandledException(e);
if (!handled)
{
throw;
}
}
finally
{
try
{
task?.Dispose();
if (transactionRunning)
{
rollbacks.Reverse(); // Do rollbacks in reverse order
foreach (var rollback in rollbacks)
{
await rollback();
}
}
// Set final result
sender.Result = results;
// Handle the result
await sender.HandleResult(sender.Result);
}
finally
{
if (notifyActivityFinished == null)
{
throw new Exception($"{nameof(notifyActivityFinished)} is null: You need to specify what happens when the operations finish");
}
try
{
await notifyActivityFinished();
}
catch (Exception e)
{
var handled = await handleUnhandledException(e);
if (!handled)
{
throw;
}
}
finally
{
_status.Remove(sender);
}
}
}
});
}
/// <summary>
/// Singular Operation
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="sender"></param>
/// <param name="operation"></param>
/// <param name="handleUnhandledException"></param>
/// <param name="handleTimeout"></param>
/// <param name="timeoutMilliseconds"></param>
/// <param name="insights"></param>
/// <param name="name"></param>
/// <param name="parameter"></param>
/// <returns></returns>
private static async Task <T> ModelExecute <T>(IModelExecution sender,
IOperation <T> operation,
Func <Exception, Task <bool> > handleUnhandledException = null,
Func <ITimeoutEvent, Task> handleTimeout = null,
int timeoutMilliseconds = 0,
IApplicationInsights insights = null,
string name = ""
)
{
if (sender == null)
{
throw new Exception($"The IModelExecution sender can not be null");
}
// Background thread
Task insight = Task.Run(() =>
{
try
{
if (insights != null)
{
insights.TrackEvent(name, $"User activated {name}");
}
}
catch (Exception ex)
{
Debug.WriteLine($"insights.TrackEvent({name}) {ex.Message}");
}
});
List <Func <IResult, Task> > rollbacks = new List <Func <IResult, Task> >();
bool transactionRunning = false;
// Setup Cancellation of Tasks if long running
var task = new CancellationTokenSource();
var exceptionState = new PropertyArgs()
{
Value = false
};
if (timeoutMilliseconds > 0)
{
if (handleTimeout != null)
{
task.Token.Register(async(state) => { if (!(bool)((PropertyArgs)state).Value)
{
await handleTimeout(new TimeoutEvent("", timeoutMilliseconds));
}
}, exceptionState);
}
else if (handleUnhandledException != null)
{
task.Token.Register(async(state) => { if (!(bool)((PropertyArgs)state).Value)
{
await handleUnhandledException(new TimeoutException());
}
}, exceptionState);
}
else
{
throw new Exception($"You must specify either {nameof(handleTimeout)} or {nameof(handleUnhandledException)} to handle a timeout.");
}
task.CancelAfter(timeoutMilliseconds);
}
T result = default(T);
try
{
// Transaction Block
transactionRunning = true;
if (operation.Function != null)
{
try
{
await Task.Run(async() => { result = await operation.Function(task.Token); }, task.Token); // Background Thread
}
catch
{
exceptionState.Value = true; // Stops registered cancel function from running, since this is exception not timeout
task?.Cancel(); // Cancel all tasks
throw; // Go to unhandled exception
}
}
transactionRunning = false;
// End of Transaction Block
}
catch (Exception e)
{
if (handleUnhandledException == null)
{
throw;
}
var handled = await handleUnhandledException(e);
if (!handled)
{
throw;
}
}
finally
{
try
{
task?.Dispose();
if (transactionRunning)
{
await operation.Rollback();
}
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message);
}
}
return(result);
}
private static async Task ViewModelExecute(IExecution sender,
List<IBaseOperation> operations,
Func<Task> notifyOfActivity = null,
Func<Task> notifyActivityFinished = null,
Func<Exception, Task<bool>> handleUnhandledException = null,
Func<Task> handleTimeout = null,
int timeoutMilliseconds = 0,
IApplicationInsights insights = null,
string name = "",
object parameter = null)
{
// If currently executing, ignore the latest request
lock (sender)
{
if (!_status.ContainsKey(sender))
_status.Add(sender, true);
else if (_status[sender])
return;
else
_status[sender] = true;
}
if (sender == null)
throw new Exception($"The {nameof(IExecution)} sender can not be null");
if (notifyOfActivity == null)
throw new Exception($"{nameof(notifyOfActivity)} is null: You must notify the user that something is happening");
await notifyOfActivity();
// Background thread
var insightTask = Task.Run(() =>
{
try
{
if (insights != null)
insights.TrackEvent(name, $"User activated {name}");
}
catch (Exception ex)
{
Debug.WriteLine($"insights.TrackEvent({name}) {ex.Message}");
}
}).ConfigureAwait(false);
await Task.Run(async () =>
{
// Debug Remove Timeout
if (App.IsDebugging)
timeoutMilliseconds = 0;
sender.Result = null;
List<Func<Task>> rollbacks = new List<Func<Task>>();
bool transactionRunning = false;
// Setup Cancellation of Tasks if long running
var task = new CancellationTokenSource();
var exceptionState = new PropertyArgs() { Value = false };
if (timeoutMilliseconds > 0)
{
if (handleTimeout != null)
task.Token.Register(async (state) => { if (!(bool)((PropertyArgs)state).Value) await handleTimeout(); }, exceptionState);
else if (handleUnhandledException != null)
task.Token.Register(async (state) => { if (!(bool)((PropertyArgs)state).Value) await handleUnhandledException(new TimeoutException()); }, exceptionState);
else
throw new Exception($"You must specify either {nameof(handleTimeout)} or {nameof(handleUnhandledException)} to handle a timeout.");
task.CancelAfter(timeoutMilliseconds);
}
IList<IResult> results = new List<IResult>();
try
{
// Transaction Block
transactionRunning = true;
foreach (var operation in operations)
{
if (operation.Rollback != null)
rollbacks.Add(operation.Rollback);
if (operation is IOperation || operation is IChainedOperation)
{
var op = operation as IOperation;
if (op.Function != null)
{
try
{
await op.Function(results, parameter, task.Token);
}
catch
{
exceptionState.Value = true; // Stops registered cancel function from running, since this is exception not timeout
task?.Cancel(); // Cancel all tasks
throw; // Go to unhandled exception
}
}
}
else
{
var op = operation as ISingleOperation;
try
{
if (op.Function != null)
{
var resultList = await op.Function(parameter, task.Token);
if (resultList != null)
foreach (var result in resultList)
results.Add(result);
}
}
catch
{
exceptionState.Value = true; // Stops registered cancel function from running, since this is exception not timeout
task?.Cancel(); // Cancel all tasks
throw; // Go to unhandled exception
}
}
if (!operation.ChainedRollback)
rollbacks.Remove(operation.Rollback);
}
rollbacks.Clear();
transactionRunning = false;
// End of Transaction Block
}
catch (Exception e)
{
if (handleUnhandledException == null)
throw;
var handled = await handleUnhandledException(e);
if (!handled)
throw;
}
finally
{
try
{
task?.Dispose();
if (transactionRunning)
{
rollbacks.Reverse(); // Do rollbacks in reverse order
foreach (var rollback in rollbacks)
await rollback();
}
// Set final result
sender.Result = results;
// Handle the result
await sender.HandleResult(sender.Result);
}
finally
{
if (notifyActivityFinished == null)
throw new Exception($"{nameof(notifyActivityFinished)} is null: You need to specify what happens when the operations finish");
try
{
await notifyActivityFinished();
}
catch (Exception e)
{
var handled = await handleUnhandledException(e);
if (!handled)
throw;
}
finally
{
_status.Remove(sender);
}
}
}
});
}