code for testing model inheritance with flask-admin

app.py

from flask import Flask, request, redirect, url_for
from flask_mongoengine import MongoEngine
from flask_admin import Admin
from flask_admin.base import expose
from flask_admin.contrib.mongoengine import ModelView
from flask_admin.helpers import get_form_data 
from flask_admin.model.helpers import get_mdict_item_or_list


app = Flask(__name__)
app.config['SECRET_KEY'] = '8e12c91677b3b3df266a770b22c82f2f'
app.config['MONGODB_SETTINGS'] = {'DB': 'testing'}

db = MongoEngine(app)


class User(db.Document):
    name = db.StringField(max_length=40)
    tags = db.ListField(db.ReferenceField('Tag'))
    password = db.StringField(max_length=40)

    def __str__(self):
        return self.name


class Tag(db.Document):
    name = db.StringField(max_length=10)
    meta = {'allow_inheritance': True}

    def __str__(self):
        return self.name


class CommentedTag(Tag):
    comment = db.StringField(max_length=180)


class ValueTag(Tag):
    value = db.IntField()


class UserView(ModelView):
    column_filters = ['name']

    column_searchable_list = ('name', 'password')

    form_ajax_refs = {
        'tags': {
            'fields': ('name',)
        }
    }


class CommentedTagView(ModelView):
    pass


class TagView(ModelView):
    @expose('/edit/', methods=('GET', 'POST'))
    def edit_view(self, *args, **kwargs):
        id = get_mdict_item_or_list(request.args, 'id')

        model = self.get_one(id)
        if isinstance(model, CommentedTag):
            return redirect(url_for('commentedtag.edit_view', id=id))
        elif isinstance(model, ValueTag):
            return redirect(url_for('valuetag.edit_view', id=id))
        return super().edit_view(*args, **kwargs)


@app.route('/')
def index():
    return 'Hello World'


if __name__ == '__main__':
    admin = Admin(app)
    admin.add_view(UserView(User))
    admin.add_view(TagView(Tag, category='Tags'))
    admin.add_view(ModelView(ValueTag, category='Tags'))
    admin.add_view(CommentedTagView(CommentedTag, category='Tags'))
    app.run(host='0.0.0.0', debug=True)