django-model-snapshot-diff 1.0.1

Django model snapshot difference

Django model snapshot difference

Make snapshot from Django model with all deep relations and get difference

Example models with other relations like OneToOne, ManyToMany etc.:

from django.db import models
from django_model_snapshot_diff.mixins import SnapshotMixin
from django_model_snapshot_diff.models import SnapshotModel


class ManyToMany(SnapshotMixin, models.Model):
    description = models.CharField(max_length=255)

    snapshot_fields = [
        ('description', 'ManyToMany DESCRIPTION field'),
    ]


class ForeignKeyDeeper(SnapshotMixin, models.Model):
    name = models.CharField(max_length=255)
    many_to_many = models.ManyToManyField('example.ManyToMany')

    snapshot_fields = [
        ('name', 'ForeignKeyDeeper NAME field'),
        ('many_to_many', 'ForeignKeyDeeper MANYTOMANY field'),
    ]


class ForeignKey(SnapshotMixin, models.Model):
    title = models.CharField(max_length=255)
    foreign_key_deeper = models.ForeignKey('example.ForeignKeyDeeper',
                                           on_delete=models.CASCADE)

    snapshot_fields = [
        ('title', 'ForeignKey TITLE field'),
        ('foreign_key_deeper', 'ForeignKey DEEPER field'),
    ]


class Relation(SnapshotMixin, models.Model):
    choice = models.CharField(choices=((1, 'A'), (2, 'B')), default=1,
                              max_length=2)
    rel_to_example = models.ForeignKey('example.Example',
                                       on_delete=models.CASCADE,
                                       related_name='relation_to_example')

    snapshot_fields = [
        ('choice', 'Relation CHOICE field'),
    ]


class Example(SnapshotModel):
    text = models.CharField(max_length=255)
    boolean = models.BooleanField(default=False)
    datetime = models.DateTimeField(auto_now=True)
    foreign_key = models.ForeignKey('example.ForeignKey',
                                    on_delete=models.CASCADE)

    snapshot_fields = [
        ('text', 'Example TEXT field'),
        ('boolean', 'Example BOOL field'),
        ('datetime', 'Example DATETIME field'),
        ('foreign_key', 'Example ForeignKey field'),
        ('relation_to_example', 'Example Relation field'),
    ]

snapshot_fields should be a list of tuples with fields to track, for example:

snapshot_fields = [
    ('model_field_name', 'Verbose name, any text')
]

How to use?

example = Example.objects.first()
example.save_snapshot()

example.text = 'new text'
example.save()

diff = example.diff(verbose=True)
assert diff == {'Example TEXT field': {'New Value:': 'new text',
                                        'Old Value': 'text'}}

Diff will contain all difference with relations, for full example look for a tests.

Testing

Tests are found in a simplified Django project in the /testapp folder. Install the project requirements and do ./manage.py test to run them.

License

See License.