:orphan:

.. _react_to_props.py:

react_to_props.py
=================

.. code-block:: py
    :linenos:


    """
    Example that demonstrates how you can write code that reacts to changes
    in properties.
    """
    
    from flexx import event
    
    
    class MyModel(event.HasEvents):
        
        @event.prop
        def foo(self, v=0):
            return float(v)
        
        @event.connect('foo')
        def react_to_foo_a(self, *events):
            for ev in events:
                print('A: foo changed from %f to %f' % (ev.old_value,
                                                        ev.new_value))
        
        @event.connect('foo')
        def react_to_foo_b(self, *events):
            print('B: foo changed from %f to %f' % (events[0].old_value, 
                                                    events[-1].new_value))
    
    m = MyModel()
    
    m.foo = 3
    m.foo = 7
    
    event.loop.iter()