Source code for crappy.modifier.trig_on_change

# coding: utf-8

from typing import Union
from .modifier import Modifier


[docs]class Trig_on_change(Modifier): """Can be used to trig an event when the value of a given label changes."""
[docs] def __init__(self, name: str) -> None: """Sets the instance attributes. Args: name (:obj:`str`): The name of the label to monitor. """ self.name = name
def evaluate(self, data: dict) -> Union[dict, None]: if not hasattr(self, 'last'): self.last = data[self.name] return data if data[self.name] == self.last: return None self.last = data[self.name] return data