No ResultHandlers

[leecrossley]

DispatchCommandResult -> ResultHandlers.ContainsKey(result.CallbackId) always fails, as ResultHandlers is an empty array :/

[leecrossley]

The webBrowser_Unloaded method which detaches event handlers of plugin commands (to prevent memory leak on page navigation) clears ALL plugin callbacks (aka ResultHandlers).

This results in the callback being lost and a "Failed to locate callback for id" error.

I'm unable to see a workaround for this without modifying the BaseCommand or NativeExecution.

[leecrossley]

As a temporary workaround, the platforms\wp8\cordovalib\Commands\BaseCommand.cs DetatchHandlers() method could be replaced with:

        public void DetachHandlers()
        {
            this.OnCommandResult = null;
            this.OnCustomScript = null;
            foreach (string callbackId in new List<string>(ResultHandlers.Keys))
            {
                if (!callbackId.ToLower().Contains("datetimepicker"))
                {
                    RemoveResultHandler(callbackId);
                }
            }
        }

[Frix33]

For avoiding monkey patching you can save the handler in selectDate method of DateTimePicker.cs class an then readd that on ResultHandler dictionary before DispatchCommandResult, its work great for me:

public event EventHandler<PluginResult> mySavedHandler;
    ....
public void selectDate(string options)
{
   ....
    if (ResultHandlers.ContainsKey(CurrentCommandCallbackId))
    {
        mySavedHandler = ResultHandlers[CurrentCommandCallbackId];
    }
    ....
}

private void dateTimePickerTask_Completed(object sender, DateTimePickerTask.DateTimeResult e)
{
......
 try {
      if (!ResultHandlers.ContainsKey(CurrentCommandCallbackId))
      {
          ResultHandlers.Add(CurrentCommandCallbackId, mySavedHandler);
      }
        .....
      DispatchCommandResult(new PluginResult(PluginResult.Status.OK, result + ""));
    }
}

[leecrossley]

Great - thanks! I've not it tested yet it but it looks good so I'll merge into master. Not sure why I didn't do this...