Populate ForeignKey's attributes like django queryset field lookup

[berinhard]

Supose that we have two models:

from django.db import models

class Bar(models.Model):
    name = models.CharField(max_length=30)

class Foo(models.Model):
    bar = models.ForeignKey(Bar)

Now, imagine if we have a single test method that needs an instance of Foo which has a reference to a Bar's instance with a specif name value such as "Bob". In the current state of mode_mommy, the way to achieve this problem is just like the code bellow:

bar = mommy.make_one(Bar, name='Bob')
foo = mommy.make_one(Foo, bar=bar)

I'm imagining an API similar to Django Queryset Field Lookup. Something lke the following code:

foo = mommy.make_one(Foo, bar__name="Bob")

What do you think? I' want to work on this feature by now...

[vandersonmota]

Looks good. It would be good to work with prepare_one, since ForeignKeys associations are persisted. Also, it can work with recipes, in order to keep a consistent API.

[berinhard]

I've looked at the recipe API but I couldn't add this feature to that API.

This is because the recipe lays on creating a model instance given specific fields. At the ends, the recipes are quita a shortcut or alias to a Model.objects.create call. So, as it lays on fields explicitly determined I think this feature just doesn't make sense with the recipes API.

PS. I've updated the pull request updating the docs

[vandersonmota]

I'm thinking if we could use the Mommy's _make_one method in order to provide such thing.