Fixed #24325 -- Documented change in ModelForm.save() foreign key access. (0af3822d) · Commits · Dom Sekotill / django

docs/releases/1.8.txt

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Original line number	Diff line number	Diff line
		@@ -711,6 +711,28 @@ Now, an error will be raised to prevent data loss::
		...
		ValueError: Cannot assign "<Author: John>": "Author" instance isn't saved in the database.

		Accessing foreign keys in ``ModelForm.save()``
		~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

		In older versions, you could access unsaved foreign key objects in
		``ModelForm.save()`` when adding new objects. For example, given ``Book`` with
		a ``ForeignKey`` to ``Author``::

		class BookForm(forms.ModelForm):
		def save(self, args, *kwargs):
		book = super(BookForm, self).save(args, *kwargs)
		book.title = "%s by %s" % (book.title, book.author.name)
		return book

		Now if the related instance hasn't been saved (for example, when adding an
		author and some inlined books in the admin), accessing the foreign key
		``book.author`` in the example) will raise ``RelatedObjectDoesNotExist``. This
		change was necessary to avoid assigning unsaved objects to relations (as
		described in the previous section).

		To adapt the example above, you could replace ``book.author.name`` with
		``self.cleaned_data['author'].name``.

		Management commands that only accept positional arguments
		~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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