Re: [SQLObject] How do ForeignKeys work?

[Ian B. <ia...@co...>]

paul wrote:
> Hi,
> 
> I have to classes like so:
> 
> CaCert(CertItem):
>  SignedCerts = MultipleJoin('Cert')
>  ...
> 
> Cert(CertItem):
>  CA = ForeignKey('CaCert')
>  Type = StringCol()
>  ...
> 
>  def _set_Type(self, value):
>   _valid = ['email', 'client', 'object', 'server']
>   if value not in _valid:
>     raise ValueError('Type must be one of %s' % _valid)
>   elif CA.Type not in  ['ca_'+value, 'ca_root']:
>     raise ValueError('CA must support cert type %s.' % type)
>   self._SO_set_Type(value)

The bug is here: CA isn't defined (just like the exception says).  Maybe 
you mean self.CA.Type?  That might not work either.

In SQLObject in SVN you could do something like:

def _create(self, id, **kw):
     if kw['CA'].Type not in ['ca_' + kw['Type'], 'ca_root']:
         raise ValueError, ...
     super(Cert, self)._create(id, **kw)

def _set_Type(self, value):
     _value = ...
     if value not in _valid: ...
     if not self._SO_creating and self.CA.Type not in ...:
     self._SO_set_Type(value)

-- 
Ian Bicking  /  ia...@co...  /  http://blog.ianbicking.org