Created
April 12, 2018 15:16
-
-
Save AlwxSin/2d7cee6731907a4d10c52dd6204b9c2e to your computer and use it in GitHub Desktop.
Mixin for tracking class attributes
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
class TrackAttrsMixin: | |
""" | |
Keep eye on TRACK_ATTRS, so we can know if they changed before doing any actions | |
TRACK_ATTRS should not be empty | |
""" | |
TRACK_ATTRS: Iterable[str] = () | |
def __init__(self, *args, **kwargs): | |
if not self.TRACK_ATTRS: | |
raise ValueError("TRACK_ATTRS should contain at least one value") | |
super().__init__(*args, **kwargs) | |
for field in self.TRACK_ATTRS: | |
value = getattr(self, field) | |
setattr(self, f"__original_{field}", value) | |
def has_changed_attributes(self) -> bool: | |
for field in self.TRACK_ATTRS: | |
old_val = getattr(self, f"__original_{field}") | |
new_val = getattr(self, field) | |
if old_val != new_val: | |
return True | |
return False | |
def attribute_changed(self, field: str) -> bool: | |
if field in self.TRACK_ATTRS: | |
old_val = getattr(self, f"__original_{field}") | |
new_val = getattr(self, field) | |
return old_val != new_val | |
else: | |
raise KeyError(f"Attribute {field} does not in tracked attributes") | |
def get_original_attribute(self, field): | |
if field not in self.TRACK_ATTRS: | |
raise KeyError(f"Attribute {field} is not in the tracked attributes") | |
return getattr(self, f"__original_{field}") |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment