[1.1.X] Apply doc addition that somehow was left out of r11834. Refs #7977.

something like this::

    class Hand(object):

        """A hand of cards (bridge style)"""

        def __init__(self, north, east, south, west):

            # Input parameters are lists of cards ('Ah', '9s', etc)

            self.north = north

    from django.db import models

    class HandField(models.Field):

        """A hand of cards (bridge style)"""

        def __init__(self, *args, **kwargs):

            kwargs['max_length'] = 104

            super(HandField, self).__init__(*args, **kwargs)

For example::

    class HandField(models.Field):

        """A hand of cards (bridge style)"""

        __metaclass__ = models.SubfieldBase

        def __init__(self, *args, **kwargs):

This ensures that the :meth:`to_python` method, documented below, will always be

called when the attribute is initialized.

Documenting your Custom Field

-----------------------------

As always, you should document your field type, so users will know what it is.

The best way to do this is to simply provide a docstring for it.  This will 

automatically be picked up by ``django.contrib.admindocs``, if you have it

installed, and the first line of it will show up as the field type in the 

documentation for any model that uses your field.  In the above examples, it 

will show up as 'A hand of cards (bridge style)'.  Note that if you provide a 

more verbose docstring, only the first line will show up in 

``django.contrib.admindocs``.  The full docstring will, of course, still be

available through ``pydoc`` or the interactive interpreter's ``help()`` 

function.

Useful methods

--------------