nopaque/app/errors/handlers.py

from flask import render_template, request
from werkzeug.exceptions import HTTPException
from . import bp


@bp.errorhandler(HTTPException)
def generic_error_handler(e):
    if (request.accept_mimetypes.accept_json
            and not request.accept_mimetypes.accept_html):
        return {'errors': {'message': e.description}}, e.code
    return render_template('errors/error.html.j2', error=e), e.code