thirdparty/google_appengine/lib/django/tests/modeltests/properties/models.py
author Sverre Rabbelier <srabbelier@gmail.com>
Sat, 06 Dec 2008 14:23:53 +0000
changeset 679 77a286ff6667
parent 109 620f9b141567
permissions -rwxr-xr-x
Introduce dynamic scope_path regexps Instead of relying on scope_path's being "one slash deep", we should instead allow for either: 1. scope_paths that have a pre-defined depth 2. scope_paths that can be arbitrarily deep We achieve 1 by setting an entities scope_logic to another logic module. We then recursively call getScopeDepth until we get to the topmost entity (that is, an unscoped entity). A little different is the solution to 2, since some entities can have an arbitrarily deep scope (such as Documents), we need to have some way of signaling this to getScopePattern. A clean solution is to return None, rather than a number. If None is returned, the SCOPE_PATH_ARG_PATTERN is returned as regexp instead, which will match an arbitrarily deeply nested scope. The solution for 2 requires that we return None somewhere in the scope_logic chain, the most straight forward method to do so is to override getScopeDepth anywhere such a scope is needed and make it return None. A more elegant solution however, is to set the scope_logic to that module in all entities that require it. Patch by: Sverre Rabbelier

"""
22. Using properties on models

Use properties on models just like on any other Python object.
"""

from django.db import models

class Person(models.Model):
    first_name = models.CharField(maxlength=30)
    last_name = models.CharField(maxlength=30)

    def _get_full_name(self):
        return "%s %s" % (self.first_name, self.last_name)

    def _set_full_name(self, combined_name):
        self.first_name, self.last_name = combined_name.split(' ', 1)

    full_name = property(_get_full_name)

    full_name_2 = property(_get_full_name, _set_full_name)

__test__ = {'API_TESTS':"""
>>> a = Person(first_name='John', last_name='Lennon')
>>> a.save()
>>> a.full_name
'John Lennon'

# The "full_name" property hasn't provided a "set" method.
>>> a.full_name = 'Paul McCartney'
Traceback (most recent call last):
    ...
AttributeError: can't set attribute

# But "full_name_2" has, and it can be used to initialise the class.
>>> a2 = Person(full_name_2 = 'Paul McCartney')
>>> a2.save()
>>> a2.first_name
'Paul'
"""}