Flask Error Handlers

errorhandlers.py

#!/usr/bin/env python

from flask import jsonify, current_app
from werkzeug.datastructures import WWWAuthenticate
from werkzeug.http import HTTP_STATUS_CODES

from flask_principal import PermissionDenied


def _make_errorhandler(code):
    def errorhandler(e):
        return jsonify({
            'message': HTTP_STATUS_CODES[code],
            'status': code,
        }), code
    return errorhandler


def unauthorized(e):
    data, status = _make_errorhandler(401)(e)
    r = Response('')
    www_auth = WWWAuthenticate()
    www_auth.type = 'Bearer'
    www_auth.realm = current_app.config['APP_NAME']
    headers = {
        'WWW-Authenticate': www_auth.to_header(),
    }
    return data, status, headers


def unprocessable_entity(e):
    try:
        messages = e.data['exc'].messages
    except Exception:  # pragma: no cover
        messages = ['Invalid Request']
    return jsonify({
        'messages': messages,
        'status': 422
    }), 422

# Install default handlers
handler_map = {
    code: _make_errorhandler(code) for code in HTTP_STATUS_CODES.iterkeys()
}

handler_map[401] = unauthorized
handler_map[422] = unprocessable_entity
handler_map[PermissionDenied] = handler_map[403]