def test_state_access():
"""Test whether calling a ``State`` object calls the ``get_state_value`` and
``set_state_value`` methods of the provider object"""
system = System()
state = State(system)
provider = Mock()
# Check read access
state(provider)
provider.get_state_value.assert_called_with(state)
# Check write access
provider.reset_mock()
state.set_value(provider, 10)
provider.set_state_value.assert_called_with(state, 10)
class ZeroOrderHold(Block):
"""A zero-order-hold block which samples an input signal when the connected
event occurs.
The block provides an event port ``event_input`` that should be connected
to the event source that shall trigger the sampling.
"""
def __init__(self, owner, shape=1, initial_condition=None):
"""
Constructor for ``ZeroOrderHold``
Args:
owner: The owner of the block (system or block)
shape: The shape of the input and output signal
initial_condition: The initial state of the sampling output
(before the first tick of the block)
"""
Block.__init__(self, owner)
self.event_input = EventPort(self)
self.event_input.register_listener(self.update_state)
self.input = Port(shape=shape)
self.output = State(
self,
shape=shape,
initial_condition=initial_condition,
derivative_function=None,
)
def update_state(self, data):
"""Update the state on a clock event
Args:
data: The time, states and signals of the system
"""
self.output.set_value(data, self.input(data))