Observe Example
Demonstration of the use of static and dynamic observers.
Example Atom Code
# --------------------------------------------------------------------------------------
# Copyright (c) 2013-2024, Nucleic Development Team.
#
# Distributed under the terms of the Modified BSD License.
#
# The full license is in the file LICENSE, distributed with this software.
# --------------------------------------------------------------------------------------
"""Demonstration of the use of static and dynamic observers."""
from atom.api import Atom, ChangeDict, Range, Str, Typed, observe
class Dog(Atom):
name = Str()
class Person(Atom):
"""A simple class representing a person object."""
name = Str()
age = Range(low=0)
dog = Typed(Dog, ())
def _observe_age(self, change: ChangeDict) -> None:
print("Age changed: {0}".format(change["value"]))
@observe("name")
def any_name_i_want(self, change: ChangeDict) -> None:
print("Name changed: {0}".format(change["value"]))
@observe("dog.name")
def another_random_name(self, change: ChangeDict) -> None:
print("Dog name changed: {0}".format(change["value"]))
class Employee(Person):
title = Str()
@observe("title")
def on_title_change(self, change: ChangeDict) -> None:
super().any_name_i_want(change)
def main():
bob = Person(name="Robert Paulson", age=40)
bob.name = "Bobby Paulson"
bob.age = 50
bob.dog.name = "Scruffy"
def watcher_func(change):
print("Watcher func change: {0}".format(change["value"]))
bob.observe("age", watcher_func)
bob.age = 51
bob.unobserve("age", watcher_func)
bob.age = 52 # No call to watcher func
if __name__ == "__main__":
main()