Flask-Admin column_formatters not called

Question

I'm using Flask-Admin and would like to add an extra field to my inline model view. Purpose is to display an Image from the filesystem.

Issue is that my column formatter is never called and the image never gets loaded. Any suggestions would be much appreciated.

class ImageView(ModelView):
    form_columns = ['id', 'mime_type', 'path']

    @staticmethod
    def _user_formatter(view, context, model, name):
        logging.warning("NOT CALLED")
        return Markup('<img src="%s">' % form.thumbgen_filename(1))

    column_formatters = dict(path=lambda v, c, m, p: ImageView._user_formatter(v, c, m, p))

    form_extra_fields = {
        'path': form.ImageUploadField('Image', base_path='/app/uploads', thumbnail_size=(400, 400, True))
    }

class VehicleModelView(ModelView):
    inline_models = [ImageView(DbModel, db.session)]

Answer 1

Try calling it without the @staticmethod

class ImageView(ModelView):
    form_columns = ['id', 'mime_type', 'path']

    def _user_formatter(view, context, model, name):
        logging.warning("NOT CALLED")
        return Markup('<img src="%s">' % form.thumbgen_filename(1))

    column_formatters = dict(path=_user_formatter)

    form_extra_fields = {
        'path': form.ImageUploadField('Image', base_path='/app/uploads', thumbnail_size=(400, 400, True))
    }

here is an example given by Flask-Admin

class ImageView(sqla.ModelView):
    def _list_thumbnail(view, context, model, name):
        if not model.path:
            return ''

        return Markup('<img src="%s">' % url_for('static',
                                                 filename=form.thumbgen_filename(model.path)))

    column_formatters = {
        'path': _list_thumbnail
    }

    # Alternative way to contribute field is to override it completely.
    # In this case, Flask-Admin won't attempt to merge various parameters for the field.
    form_extra_fields = {
        'path': form.ImageUploadField('Image',
                                      base_path=file_path,
                                      thumbnail_size=(100, 100, True))
    }