Source code for auditlog.diff

from __future__ import unicode_literals

from django.conf import settings
from django.core.exceptions import ObjectDoesNotExist
from django.db.models import Model, NOT_PROVIDED, DateTimeField
from django.utils import timezone
from django.utils.encoding import smart_text

[docs]def track_field(field): """ Returns whether the given field should be tracked by Auditlog. Untracked fields are many-to-many relations and relations to the Auditlog LogEntry model. :param field: The field to check. :type field: Field :return: Whether the given field should be tracked. :rtype: bool """ from auditlog.models import LogEntry # Do not track many to many relations if field.many_to_many: return False # Do not track relations to LogEntry if getattr(field, 'rel', None) is not None and == LogEntry: return False return True
[docs]def get_fields_in_model(instance): """ Returns the list of fields in the given model instance. Checks whether to use the official _meta API or use the raw data. This method excludes many to many fields. :param instance: The model instance to get the fields for :type instance: Model :return: The list of fields for the given model (instance) :rtype: list """ assert isinstance(instance, Model) # Check if the Django 1.8 _meta API is available use_api = hasattr(instance._meta, 'get_fields') and callable(instance._meta.get_fields) if use_api: return [f for f in instance._meta.get_fields() if track_field(f)] return instance._meta.fields
[docs]def get_field_value(obj, field): """ Gets the value of a given model instance field. :param obj: The model instance. :type obj: Model :param field: The field you want to find the value of. :type field: Any :return: The value of the field as a string. :rtype: str """ if isinstance(field, DateTimeField): # DateTimeFields are timezone-aware, so we need to convert the field # to its naive form before we can accuratly compare them for changes. try: value = field.to_python(getattr(obj,, None)) if value is not None and settings.USE_TZ: value = timezone.make_naive(value, timezone=timezone.utc) except ObjectDoesNotExist: value = field.default if field.default is not NOT_PROVIDED else None else: try: value = smart_text(getattr(obj,, None)) except ObjectDoesNotExist: value = field.default if field.default is not NOT_PROVIDED else None return value
[docs]def model_instance_diff(old, new): """ Calculates the differences between two model instances. One of the instances may be ``None`` (i.e., a newly created model or deleted model). This will cause all fields with a value to have changed (from ``None``). :param old: The old state of the model instance. :type old: Model :param new: The new state of the model instance. :type new: Model :return: A dictionary with the names of the changed fields as keys and a two tuple of the old and new field values as value. :rtype: dict """ from auditlog.registry import auditlog if not(old is None or isinstance(old, Model)): raise TypeError("The supplied old instance is not a valid model instance.") if not(new is None or isinstance(new, Model)): raise TypeError("The supplied new instance is not a valid model instance.") diff = {} if old is not None and new is not None: fields = set(old._meta.fields + new._meta.fields) model_fields = auditlog.get_model_fields(new._meta.model) elif old is not None: fields = set(get_fields_in_model(old)) model_fields = auditlog.get_model_fields(old._meta.model) elif new is not None: fields = set(get_fields_in_model(new)) model_fields = auditlog.get_model_fields(new._meta.model) else: fields = set() model_fields = None # Check if fields must be filtered if model_fields and (model_fields['include_fields'] or model_fields['exclude_fields']) and fields: filtered_fields = [] if model_fields['include_fields']: filtered_fields = [field for field in fields if in model_fields['include_fields']] else: filtered_fields = fields if model_fields['exclude_fields']: filtered_fields = [field for field in filtered_fields if not in model_fields['exclude_fields']] fields = filtered_fields for field in fields: old_value = get_field_value(old, field) new_value = get_field_value(new, field) if old_value != new_value: diff[] = (smart_text(old_value), smart_text(new_value)) if len(diff) == 0: diff = None return diff