|
|
@@ -844,6 +844,33 @@ built-in model methods, adding new arguments. If you use ``*args,
|
|
|
**kwargs`` in your method definitions, you are guaranteed that your
|
|
|
code will automatically support those arguments when they are added.
|
|
|
|
|
|
+If you wish to update a field value in the :meth:`~Model.save` method, you may
|
|
|
+also want to have this field added to the ``update_fields`` keyword argument.
|
|
|
+This will ensure the field is saved when ``update_fields`` is specified. For
|
|
|
+example::
|
|
|
+
|
|
|
+ from django.db import models
|
|
|
+ from django.utils.text import slugify
|
|
|
+
|
|
|
+ class Blog(models.Model):
|
|
|
+ name = models.CharField(max_length=100)
|
|
|
+ slug = models.TextField()
|
|
|
+
|
|
|
+ def save(
|
|
|
+ self, force_insert=False, force_update=False, using=None, update_fields=None
|
|
|
+ ):
|
|
|
+ self.slug = slugify(self.name)
|
|
|
+ if update_fields is not None and "name" in update_fields:
|
|
|
+ update_fields = {"slug"}.union(update_fields)
|
|
|
+ super().save(
|
|
|
+ force_insert=force_insert,
|
|
|
+ force_update=force_update,
|
|
|
+ using=using,
|
|
|
+ update_fields=update_fields,
|
|
|
+ )
|
|
|
+
|
|
|
+See :ref:`ref-models-update-fields` for more details.
|
|
|
+
|
|
|
.. admonition:: Overridden model methods are not called on bulk operations
|
|
|
|
|
|
Note that the :meth:`~Model.delete()` method for an object is not
|
sarahboyce