Question

Imagine I have a coroutine which uses the implementation of Loader included in the CM docs, and I use it to show a busy indicator on my page

Now imagine the user attempts to add an object which already exists to the data store – naturally during the coroutine the ‘save’ operation will fail, meaning the coroutine will cancel execution

If this happens, the enumerator never reaches my Loader.Hide() call to hide the busy indicator – I’m wondering if there is already a mechanism in place to allow some IResult implementations to execute even if the coroutine fails?

Example:

    public IEnumerator<IResult> SaveData()
    {
        yield return Framework.Coroutines.Loader.Show("Saving Data");
        yield return new Framework.Coroutines.SaveOperation(SomeObject);
        yield return Framework.Coroutines.Loader.Hide();
    }

If the coroutine fails legitimately on the second step, the busy indicator remains on screen, leaving the user no chance to correct their errors and attempt a re-save (and stopping any interaction with the underlying UI!)

I could just extend the implementation of coroutine and have iterators that have a flag which says whether they are allowed to execute when there is an error – just wondering if anyone has done this already or if it’s a part of the framework I’m missing?

Answer 1

You could also use Caliburn.Micro Action Filters. See SetBusyAttribute.
The declarative style of attributes is transparent and makes the code easier to manage.