A good way to show server initiated feedback

[wallytax]

When saving/deleting data, I sometimes would like to show feedback to the user when the save/delete action is performed by the server (I use a JSON RestDataSource). As an example, I could think of a employee reporting hours per day and after a save action I could show a dialog with the total hours in the month.

What kind of event/callback mechanism would I use? I am thinking about transformResponse in the data source and using extra meta data. For a create or update action, this could be:

response: {
  status: 0,
  data: {
    id: 1,
    name: 'John Doe',
    date: '2010-09-16',
    hours: 5
  },
  hours_per_month: 100
}

For a delete action, it's something like this:

response: {
  status: 0,
  data: {
    id: 1
  },
  hours_per_month: 95
}

The reason I choose transformResponse is that it seems to be triggered for all data operations (fetch, add, update, delete) and it is widget independent: it works for a form and a editable grid.

My objections to this approach is that a data source doesn't feel like the right place to update visual components.

Any thoughts or ideas?
Thanks in advance.

[Isomorphic]

There's really no shortcut for using component-specific callbacks to do this (such as the callback for saveData(), or editComplete()). While you could add this at the DataSource layer as a short-term hack, it's likely to misfire some time in the future, for example, confirmation dialogs popping up in the middle of a multi-row drag and drop that happens to be issuing "update" or "add" operations.