Events

Shows how a client loads an Aseba script to a remote node, and interacts with it using user-defined events.

from pyaseba.client import Client

client = Client()
client.connect("tcp", port=33333)
node_id, connection = client.wait_node()

The remote node defines variables

desc = client.get_description(node_id=node_id)
assert desc
list(desc.variables)

['_productId', 'args', 'counter', 'id', 'source', 'value']

and events

list(desc.local_events)

['event']

which are accessible from Aseba scripts like this one

script = """
onevent reset
counter = 0

onevent event
emit count counter
"""

where

• event reset resets the counter variable when received on the remote node,

• event count is broadcasted each time the local event (which is not accessible outside the remote node) is emitted by the remote node.

client.load_script(node_id=node_id,
                   script=script,
                   events={"count": 1, "reset": 0})

The description should now contain the new events

desc = client.get_description(node_id=node_id)
assert desc
desc.user_events

{'count': 1, 'reset': 0}

Let us ask the remote node to start running the script

client.cmd_run(node_id)

Let us reset the counter

client.emit_event(node_id=node_id, name="reset")

and start waiting for count events.

for _ in range(5):
    event = client.get_event(node_id=node_id, name="count", wait_ms=1000)
    print(f"Received {event}")

Received Event(source=0, name='count', data=[1])
Received Event(source=0, name='count', data=[2])
Received Event(source=0, name='count', data=[3])
Received Event(source=0, name='count', data=[4])
Received Event(source=0, name='count', data=[5])

client.close()