Make findNearestUsers() code in soc/logic/site/id_user.py more generic and
move it to soc/logic/model.py. Orginal findNearest...() functions in
id_user.py are now convenience wrappers.
Add typed-query string construction functions to model.py.
Move getFulLClassName() from key_name.py model.py, since it has more to do
with Model types than key names.
Swap 'offset' and 'limit' and make 'limit' arguments non-optional. Also,
stop adding 1 inside the ...ForLimitAndOffset() functions and make the
callers do it (since it was being added for a very UI-specific reason of
whether or not to display a "Next>" link).
Patch by: Todd Larsen
Review by: Pawel Solyga
Review URL: http://codereviews.googleopensourceprograms.com/1401
"""
Various data structures used in query construction.
Factored out from django.db.models.query so that they can also be used by other
modules without getting into circular import difficulties.
"""
from copy import deepcopy
from django.utils import tree
class QueryWrapper(object):
"""
A type that indicates the contents are an SQL fragment and the associate
parameters. Can be used to pass opaque data to a where-clause, for example.
"""
def __init__(self, sql, params):
self.data = sql, params
class Q(tree.Node):
"""
Encapsulates filters as objects that can then be combined logically (using
& and |).
"""
# Connection types
AND = 'AND'
OR = 'OR'
default = AND
def __init__(self, *args, **kwargs):
super(Q, self).__init__(children=list(args) + kwargs.items())
def _combine(self, other, conn):
if not isinstance(other, Q):
raise TypeError(other)
obj = deepcopy(self)
obj.add(other, conn)
return obj
def __or__(self, other):
return self._combine(other, self.OR)
def __and__(self, other):
return self._combine(other, self.AND)
def __invert__(self):
obj = deepcopy(self)
obj.negate()
return obj