[storm] python properties and storm properties...

[Jamu Kakar]

Hi Jason,

Please CC the list when you respond to messages so that everyone can see 
the complete thread.

Thanks,
J.

Jason R Briggs wrote:
> Thanks for that.    I'd already come up with the former solution, but 
> decided it wasn't the right answer since it then requires the column 
> name to be changed -- thus the column is different from the actual 
> property.  Not a big deal, but I figured there might be a more elegant 
> way.  Your second solution might be the answer, thanks.
> 
> Jamu Kakar wrote:
>> Hi Jason,
>>
>> Jason R Briggs wrote:
>> > This might be a bit of a dumb question, but I have to admit I'm
>> > struggling to find the right answer.
>>
>> The only dumb question is the one you don't ask. :)
>>
>> > Is there a way to use a Storm property in a similar way to a python
>> > property?  For example, in a normal class I can define a setter and
>> > getter and then a property which uses those methods:
>> >
>> > def set_password(self, password):
>> >     self._password = encrypt_password(self.username, password)
>> >
>> > def get_password(self):
>> >     return self._password
>> >
>> > password = property(get_password, set_password)
>> >
>> > Can I do something similar with a storm property?
>>
>> You can do this:
>>
>> class Person(Storm):
>>
>>     __storm_table__ = "person"
>>
>>     id = Int(primary=True)
>>     password_hash = RawStr(allow_none=False)
>>
>>     def set_password(self, password):
>>         self.password_hash = encrypt_password(self.username, password)
>>
>>     def get_password(self):
>>         return self.password_hash
>>
>>     password = property(get_password, set_password)
>>
>> Another option is to create a custom property to do what you want
>> (useful if you need the behaviour in more than one place and don't
>> want to repeat the set/get property boilerplate):
>>
>> from storm.variables import RawStrVariable
>> from storm.properties import SimpleProperty
>>
>> class PasswordVariable(RawStrVariable):
>>
>>     def parse_set(self, value, from_db):
>>         return super(PasswordVariable, 
>> self).parse_set(encrypt_password(value),
>>                                                        from_db)
>>
>> class Password(SimpleProperty):
>>
>>     variable_class = PasswordVariable
>>
>> And then do:
>>
>> class Person(Storm):
>>
>>     __storm_table__ = "person"
>>
>>     id = Int(primary=True)
>>     password = Password(allow_none=False)
>>
>> I haven't tested either of these solutions, but I believe they will
>> both work.
>>
>> Thanks,
>> J.
>>
>