"""

Regression tests for proper working of ForeignKey(null=True). Tests these bugs:

    * #7512: including a nullable foreign key reference in Meta ordering has un

xpected results

"""

from django.db import models

# The first two models represent a very simple null FK ordering case.

class Author(models.Model):

    name = models.CharField(max_length=150)

class Article(models.Model):

    title = models.CharField(max_length=150)

    author = models.ForeignKey(Author, null=True)

    def __unicode__(self):

        return u'Article titled: %s' % (self.title, )

    class Meta:

        ordering = ['author__name', ]

# These following 4 models represent a far more complex ordering case.

class SystemInfo(models.Model):

    system_name = models.CharField(max_length=32)

class Forum(models.Model):

    system_info = models.ForeignKey(SystemInfo)

    forum_name = models.CharField(max_length=32)

class Post(models.Model):

    forum = models.ForeignKey(Forum, null=True)

    title = models.CharField(max_length=32)

    def __unicode__(self):

        return self.title

class Comment(models.Model):

    post = models.ForeignKey(Post, null=True)

    comment_text = models.CharField(max_length=250)

    class Meta:

        ordering = ['post__forum__system_info__system_name', 'comment_text']

    def __unicode__(self):

        return self.comment_text