private void DispatchCommandTask(DeviceBase device, Command cCommand)
{
// invoke device
DeviceCommandResult result;
try
{
var command = new DeviceCommand(cCommand.Name.Trim(),
cCommand.Parameters == null ? null : cCommand.Parameters.DeepClone(),
cCommand.UserId);
result = device.HandleCommand(command, _cancellationSource.Token);
}
catch (OperationCanceledException)
{
return;
}
catch (Exception ex)
{
// operation faulted - log the error and send failed result
Logger.Error(string.Format("Exception while handling a command '{0}' by device {1} ({2})", cCommand.Name, device.ID, device.Name), ex);
result = new DeviceCommandResult("Failed", "An error occurred while handling the command");
}
// send command result
cCommand.Status = result.Status;
cCommand.Result = result.Result == null ? null : JToken.FromObject(result.Result, device.JsonSerializer);
SendCommandResult(device, cCommand);
}
/// <summary>
/// Handles incoming device command, override to implement custom logic.
/// Default implementation uses reflection to execute action method with matching <see cref="DeviceCommandAttribute"/> attribute.
/// </summary>
/// <param name="command"><see cref="DeviceCommand"/> object to handle.</param>
/// <param name="token">Thread cancellation token.</param>
/// <returns><see cref="DeviceCommandResult"/> object with command execution result.</returns>
public virtual DeviceCommandResult HandleCommand(DeviceCommand command, CancellationToken token)
{
MethodInfo method;
if (_deviceCommands.TryGetValue(command.Name, out method))
{
var commandType = method.GetParameters()[0].ParameterType;
var parameters = commandType == typeof(DeviceCommand) ? command :
(command.Parameters == null ? Activator.CreateInstance(commandType) :
command.Parameters.ToObject(commandType, JsonSerializer));
return((DeviceCommandResult)method.Invoke(this, new object[] { parameters, token }));
}
return(OnHandleUnknownCommand(command, token));
}
/// <summary>
/// Handles unknown device command, override to implement custom logic.
/// Default implementation returns <see cref="DeviceCommandResult"/> object with "Failed" result.
/// </summary>
/// <param name="command"><see cref="DeviceCommand"/> object to handle.</param>
/// <param name="token">Thread cancellation token.</param>
/// <returns><see cref="DeviceCommandResult"/> object</returns>
protected virtual DeviceCommandResult OnHandleUnknownCommand(DeviceCommand command, CancellationToken token)
{
return(new DeviceCommandResult("Failed", "There is no handler for this command"));
}