Employee Example

Simple example of a class hierarchy built on atom.

Tip

To see this example in action, download it from employee and run:

$ python employee.py

Example Atom Code

# --------------------------------------------------------------------------------------
# Copyright (c) 2013-2022, Nucleic Development Team.
#
# Distributed under the terms of the Modified BSD License.
#
# The full license is in the file LICENSE, distributed with this software.
# --------------------------------------------------------------------------------------
"""Simple example of a class hierarchy built on atom.

"""
import datetime

from atom.api import (
    Atom,
    Bool,
    ChangeDict,
    Int,
    Range,
    Str,
    Tuple,
    Typed,
    Value,
    observe,
)


class Person(Atom):
    """A simple class representing a person object."""

    last_name = Str()

    first_name = Str()

    age = Range(low=0)

    dob = Value(datetime.date(1970, 1, 1))

    debug = Bool(False)

    @observe("age")
    def debug_print(self, change: ChangeDict) -> None:
        """Prints out a debug message whenever the person's age changes."""
        if self.debug:
            templ = "{first} {last} is {age} years old."
            s = templ.format(first=self.first_name, last=self.last_name, age=self.age)
            print(s)


class Employer(Person):
    """An employer is a person who runs a company."""

    # The name of the company
    company_name = Str()


class Employee(Person):
    """An employee is person with a boss and a phone number."""

    # The employee's boss
    boss = Typed(Employer)

    # The employee's phone number as a tuple of 3 ints
    phone = Tuple(Int())

    # This method will be called automatically by atom when the
    # employee's phone number changes
    def _observe_phone(self, val: ChangeDict) -> None:
        if val["type"] == "update":
            msg = "received new phone number for %s: %s"
            print(msg % (self.first_name, val["value"]))


if __name__ == "__main__":
    # Create an employee with a boss
    boss_john = Employer(
        first_name="John", last_name="Paw", company_name="Packrat's Cats"
    )
    employee_mary = Employee(
        first_name="Mary", last_name="Sue", boss=boss_john, phone=(555, 555, 5555)
    )

    employee_mary.phone = (100, 100, 100)
    employee_mary.age = 40  # no debug message
    employee_mary.debug = True
    employee_mary.age = 50