Flask-Admin: How to change model using on_model_change?

Question

I'm trying to set a field's value to be based on another field in the same form:

    def on_model_change(form, model, is_created):
        model.textcolumn.data = model.textcolumn2.data

Updating via the Flask-Admin interface raises no exceptions, but no changes were made to the value in model.textcolumn.

Inspecting the "model" object, I also noticed this is not the same as the SQLAlchemy model used to generate the ModelView.

How can I change model.textcolumn's value to model.textcolumn2's value? Is there a way to access the SQLAlchemy model object directly? This would be much better.

Answer 1

I did it using the admin form for a specific model

class YourModelAdmin(MyModelView):
    form_overrides = dict(filename=FileField)

    def on_model_change(self, form, instance):
        pass

   admin.add_view(YourModelAdmin(YourModel, db.session))