"""

Constraints

"""

from sqlobject.compat import PY2

if not PY2:

# alias for python 3 compatability

long = int

class BadValue(ValueError):

def __init__(self, desc, obj, col, value, *args):

self.desc = desc

self.col = col

# I want these objects to be garbage-collectable, so

# I just keep their repr:

self.obj = repr(obj)

self.value = repr(value)

fullDesc = "%s.%s %s (you gave: %s)" \

% (obj, col.name, desc, value)

ValueError.__init__(self, fullDesc, *args)

def isString(obj, col, value):

if not isinstance(value, str):

raise BadValue("only allows strings", obj, col, value)

def notNull(obj, col, value):

if value is None:

raise BadValue("is defined NOT NULL", obj, col, value)

def isInt(obj, col, value):

if not isinstance(value, (int, long)):

raise BadValue("only allows integers", obj, col, value)

def isFloat(obj, col, value):

if not isinstance(value, (int, long, float)):

raise BadValue("only allows floating point numbers", obj, col, value)

def isBool(obj, col, value):

if not isinstance(value, bool):

raise BadValue("only allows booleans", obj, col, value)

class InList:

def __init__(self, _l):

self.list = _l

def __call__(self, obj, col, value):

if value not in self.list:

raise BadValue("accepts only values in %s" % repr(self.list),

obj, col, value)

class MaxLength:

def __init__(self, length):

self.length = length

def __call__(self, obj, col, value):

try:

length = len(value)

except TypeError:

raise BadValue("object does not have a length",

obj, col, value)

if length > self.length:

raise BadValue("must be shorter in length than %s"

% self.length,

obj, col, value)