56 lines
1.6 KiB
Python
56 lines
1.6 KiB
Python
import copy
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from django.db import models
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from django.db.models.query import Q
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class RevisionableModel(models.Model):
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base = models.ForeignKey('self', null=True)
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title = models.CharField(blank=True, max_length=255)
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def __unicode__(self):
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return u"%s (%s, %s)" % (self.title, self.id, self.base.id)
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def save(self):
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super(RevisionableModel, self).save()
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if not self.base:
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self.base = self
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super(RevisionableModel, self).save()
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def new_revision(self):
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new_revision = copy.copy(self)
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new_revision.pk = None
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return new_revision
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__test__ = {"API_TESTS": """
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### Regression tests for #7314 and #7372
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>>> rm = RevisionableModel.objects.create(title='First Revision')
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>>> rm.pk, rm.base.pk
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(1, 1)
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>>> rm2 = rm.new_revision()
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>>> rm2.title = "Second Revision"
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>>> rm2.save()
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>>> print u"%s of %s" % (rm2.title, rm2.base.title)
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Second Revision of First Revision
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>>> rm2.pk, rm2.base.pk
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(2, 1)
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Queryset to match most recent revision:
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>>> qs = RevisionableModel.objects.extra(where=["%(table)s.id IN (SELECT MAX(rev.id) FROM %(table)s AS rev GROUP BY rev.base_id)" % {'table': RevisionableModel._meta.db_table,}],)
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>>> qs
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[<RevisionableModel: Second Revision (2, 1)>]
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Queryset to search for string in title:
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>>> qs2 = RevisionableModel.objects.filter(title__contains="Revision")
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>>> qs2
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[<RevisionableModel: First Revision (1, 1)>, <RevisionableModel: Second Revision (2, 1)>]
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Following queryset should return the most recent revision:
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>>> qs & qs2
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[<RevisionableModel: Second Revision (2, 1)>]
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"""}
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