BoundField.as_hidden() assumes hidden_widget is a class

[Chris Beaven]

The hidden_widget of a field could just as easily be (and is, in a case I'm using) a Widget instance rather than a Widget class but BoundField.as_hidden() assumes that it is always a class.

Simple patch attached checks first before trying to instantiate the hidden_widget.

[Adrian Holovaty]

What's the use case for hidden_widget being an instance rather than a class?

[Luke Plant]

isinstance bad, duck typing good: this patch would break if hidden_widget:

• was a class but not a subclass of Widget
• was some other callable that returned a widget e.g. a function that wraps a Widget constructor

In fact, thinking of the latter, you can work around this perfectly if you set hidden_widget = lambda: my_widget_instance, AFAICS

So, seeing it is currently flexible enough to cope, and adding this would make it much less flexible, I'm closing WONTFIX, please reopen if I missed something.