urlman metaclass hack

"""
If the code in the urlman docs is run with the below Urls class:

.. code-block:: python

    class Group(models.Model):

        ...

        class urls(Urls):
            view = "/{self.slug}/"
            users = "{view}users/"
            admin = "{view}admin/"

This model will also have a ``get_absolute_url`` method also:

.. code-block:: pycon

    >>> group = Group(slug="hello")
    >>> group.get_absolute_url()
    '/hello/'
    >>>> group.urls.view
    '/hello/'
"""

import urlman


class UrlsMeta(urlman.UrlsMetaclass):
    def __set_name__(self, cls, name, **kwargs):
        urls = self.urls
        def get_absolute_url(self):
            return self.urls.view
        if not hasattr(cls, 'get_absolute_url') and 'view' in urls:
            setattr(cls, 'get_absolute_url', get_absolute_url)


class Urls(urlman.Urls, metaclass=UrlsMeta):
    """
    urlman.Urls that adds a get_absolute_url method automatically
    """