[Twisted-web] support for other languages in newov

[Mike Mueller]

I am playing around with newov and especially freeform. It is very nice.
Since I need to support German at my web site it would nice if error=20
messages and other information that are sent back to the visitor could be=20
in an other language.
I came up with a simple solution using a dict that holds all the messages=20
in different languages.

multilang.py

multilangDict =3D {'emptyPasswd':{'eng':"Please enter a non-empty=
 password.",
                                'de':"Ein leeres Passwort ist nicht=20
erlaubt. Eingabe bitte wiederholen!"
                                 },
                  'passwdDontMatch':{'eng':"Passwords do not match. Please=
=20
reenter.",
                                     'de':"Die Passw=F6rter stimmen nicht=20
=FCberrein. Eingabe bitte wiederholen!"
                                     }
                  }

Umlauts (=F6 and =FC) work with my browser settings but might need to use &=
=20
uml; notation:

multilang2.py

from newov stan import xml
multilangDict =3D {'emptyPasswd':{'eng':"Please enter a non-empty=
 password.",
                                'de':"Ein leeres Passwort ist nicht=20
erlaubt. Eingabe bitte wiederholen!"
                                 },
                  'passwdDontMatch':{'eng':"Passwords do not match. Please=
=20
reenter.",
                                     'de':xml("Die Passw¨rter stimmen=20
nicht =E6uuml;berrein. Eingabe bitte wiederholen!")
                                     }
                  }

Unicode might be necessary if languages like Chinese are needed.

in freeform.py you just put:

from nevow import multilang
multilangDict =3D multilang.multilangDict
lang =3D 'de'  #read from configuration somewhere or set by visitor or url=
=20
like www.example.com/mylang/foo

and change the formless.InputError arguments to dict lookups, e.g.:

class PasswordValidator(components.Adapter):
     __implements__ =3D IInputValidator,

     def validate(self, context, boundTo, data):
         """Password needs to look at two passwords in the data,
         """
         pw1 =3D data[0]
         if pw1 =3D=3D '':
             raise formless.InputError(multilangDict['emptyPasswd'][lang])=
=20
#changed
         args =3D context.locate(iwoven.IRequest).args
         binding =3D context.locate(formless.IBinding)
         pw2 =3D args.get("%s____2" % binding.name, [''])[0]
         if pw1 !=3D pw2:
             raise=20
formless.InputError(multilangDict['passwdDontMatch'][lang]) #changed f
         return self.original.coerce(data[0])


This works the way I want it. Since the number of messages is rather small=
=20
a dict seems ok in terms of memory usage.

Because the languages part is in a separate file, it can be maintained by=20
anybody who knows the (foreign) languages without the need of looking=20
through the code. If the same message is used at several places changing it=
=20
becomes much easier too.

How do you thing about it?


Mike