def switch_light(number, state):
if state:
print(
"************************************************************************"
)
print(" User {} (local identifier: {})".format(
weblab_user.username, weblab_user.data['local_identifier']))
print(
" Imagine that light {} is turning on! "
.format(number))
print(
"************************************************************************"
)
redis.set('hardware:lights:{}'.format(number), 'off')
else:
print(
"************************************************************************"
)
print(
" Imagine that light {} is turning off! "
.format(number))
print(
"************************************************************************"
)
redis.set('hardware:lights:{}'.format(number), 'on')
def program_device(code):
if weblab_user.time_left < 10:
print("************************************************************************")
print("Error: typically, programming the device takes around 10 seconds. So if ")
print("the user has less than 10 seconds (%.2f) to use the laboratory, don't start " % weblab_user.time_left)
print("this task. Otherwise, the user session will still wait until the task")
print("finishes, delaying the time assigned by the administrator")
print("************************************************************************")
return {
'success': False,
'reason': "Too few time: {}".format(weblab_user.time_left)
}
print("************************************************************************")
print("You decided that you wanted to program the robot, and for some reason, ")
print("this takes time. In weblablib, you can create a 'task': something that ")
print("you can start, and it will be running in a different thread. In this ")
print("case, this is lasting for 10 seconds from now ")
print("************************************************************************")
if redis.set('hardware:microcontroller:programming', 0) == 0:
# Just in case two programs are sent at the very same time
return {
'success': False,
'reason': "Already programming"
}
socketio.emit('board-status', hardware_status(), namespace='/mylab')
for step in range(10):
time.sleep(1)
redis.set('hardware:microcontroller:programming', step)
socketio.emit('board-status', hardware_status(), namespace='/mylab')
print("Still programming...")
if code == 'division-by-zero':
print("************************************************************************")
print("Oh no! It was a division-by-zero code! Expect an error!")
print("************************************************************************")
pipeline = redis.pipeline()
pipeline.set('hardware:microcontroller:state', 'failed')
pipeline.delete('hardware:microcontroller:programming')
pipeline.execute()
socketio.emit('board-status', hardware_status(), namespace='/mylab')
10 / 0 # Force an exception to be raised
print("************************************************************************")
print("Yay! the robot has been programmed! Now you can retrieve the result ")
print("************************************************************************")
pipeline = redis.pipeline()
pipeline.set('hardware:microcontroller:state', 'programmed')
pipeline.delete('hardware:microcontroller:programming')
pipeline.execute()
socketio.emit('board-status', hardware_status(), namespace='/mylab')
return {
'success': True
}
def clean_resources():
"""
This code could be in dispose(). However, since we want to call this low-level
code from outside any request and we can't (since we're using
weblab_user.username in dispose())... we separate it. This way, this code can
be called from outside using 'flask clean-resources'
"""
redis.set('hardware:microcontroller', 'empty')
print("Microcontroller restarted")
def start(client_data, server_data):
print("************************************************************************")
print("Preparing laboratory for user {}...".format(weblab_user.username))
print()
print(" - Typically, here you prepare resources.")
print(" - Since this method is run *before* the user goes to the lab, you can't")
print(" store information on Flask's 'session'. But you can store it on:")
print(" weblab_user.data")
weblab_user.data['local_identifier'] = weblab.create_token()
print(" In this case: {}".format(weblab_user.data['local_identifier']))
print()
print("************************************************************************")
for light in range(LIGHTS):
redis.set('hardware:lights:{}'.format(light), 'off')
redis.set('hardware:microcontroller:state', 'empty')
redis.delete('hardware:microcontroller:programming')