Detecting changes of model field values.

dirtydecector.py

""" Detect changes of Django Models.
"""


class ChangeDetector:
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self._dirty_fields = {f: False for f in self._get_field_names()}
        self._inited = True

    def __setattr__(self, name, value):
        super().__setattr__(name, value)
        if hasattr(self, '_inited'):
            if name in self._get_field_names():
                self._dirty_fields[name] = True

    def _get_field_names(self):
        return (f.name for f in self._meta.fields)

    def is_dirty(self, fields=None):
        fields = fields or self._get_field_names()
        return any(self._dirty_fields[f] for f in fields)