tabletop-frog/ttfrog/webserver/forms.py

from ttfrog.db.manager import db
from wtforms.fields import SelectField, SelectMultipleField

class DeferredSelectMultipleField(SelectMultipleField):
    def __init__(self, *args, model=None, **kwargs):
        super().__init__(*args, **kwargs)
        self.choices = db.query(model).all()

class DeferredSelectField(SelectField):
    def __init__(self, *args, model=None, **kwargs):
        super().__init__(*args, **kwargs)
        self.choices = db.query(model).all()