forms.py 文件源码

def __call__(self, field, **kwargs):
            kwargs.setdefault('id', field.id)
            kwargs.setdefault('type', self.input_type)
            kwargs.setdefault('value', field.id)
            return HTMLString('<button %s>%s</button>' % (self.html_params(name=field.name, **kwargs),
                                                          field.label.text))

    # Represents a <button type="submit">, allowing checking if a submit button has been pressed.