id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
23349	Document that migrations must have dependencies in order to access other apps' models	no	nobody	"When using `migrations.RunPython` the first parameter passed to the function is documented as being equivalent to South's `orm['app.Model']`. In South, the orm has a complete view of all the models, whereas the `app` parameter only contains apps/models for which the current migration depends on.

I've attached a simple project. To demonstrate this issue, run `python manage.py migrate` in the app.
The project contains 3 apps: spam, eggs, and cheese. There are dependencies between spam and eggs, but cheese is isolated. I created an empty migration in eggs, and print all the models I can find via the `apps` parameter. I was expecting it to output all of the models in all three apps, but instead it only prints the models for which the migration depends on.

The apps models are as follows:
eggs: Egg (links to spam.Beef)
cheese: Cheese (no links)
spam: Beef (no links), Potato( links to spam.Beef)

I created an empty migration in eggs which lists all the models in the apps parameter, this is what it prints:

{{{
# print(cls) for cls in (for cls in  apps.get_app_configs())
AppConfigStub: eggs
class 'Egg'
AppConfigSub: spam
class 'Beef'
class 'Potato'
----
# print(cls) for cls in apps.get_models()
class 'Egg'
class 'Beef'
class 'Potato'
}}}

Notice how it neglects to print out anything from the 'cheese' app."	Cleanup/optimization	closed	Documentation	1.7-rc-3	Normal	fixed			Accepted	0	0	0	0	0	0