xep_0077_5.py

    def plugin_init(self):
        self.description = "In-Band Registration"
        self.xep = "0077"
        self.form_fields = ('username', 'password')
        ... remainder of plugin_init

    ...

    def __handleRegistration(self, iq):
        if iq['type'] == 'get':
            # Registration form requested
            userData = self.backend[iq['from'].bare]
            self.sendRegistrationForm(iq, userData)

    def setForm(self, *fields):
        self.form_fields = fields

    def sendRegistrationForm(self, iq, userData=None):
        reg = iq['register']
        if userData is None:
            userData = {}
        else:
            reg['registered'] = True

        for field in self.form_fields:
            data = userData.get(field, '')
            if data:
                # Add field with existing data
                reg[field] = data
            else:
                # Add a blank field
                reg.addField(field)

        iq.reply().setPayload(reg.xml)
        iq.send()