indico/util/json.py

   1 # This file is part of Indico.
   2 # Copyright (C) 2002 - 2015 European Organization for Nuclear Research (CERN).
   3 #
   4 # Indico is free software; you can redistribute it and/or
   5 # modify it under the terms of the GNU General Public License as
   6 # published by the Free Software Foundation; either version 3 of the
   7 # License, or (at your option) any later version.
   8 #
   9 # Indico is distributed in the hope that it will be useful, but
  10 # WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 # General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU General Public License
  15 # along with Indico; if not, see <http://www.gnu.org/licenses/>.
  16
  17 from __future__ import absolute_import
  18
  19 import traceback
  20 from datetime import datetime, date
  21
  22 from flask import current_app, session
  23 from persistent.dict import PersistentDict
  24 from speaklater import _LazyString
  25 from werkzeug.exceptions import Forbidden
  26
  27 from indico.web.util import get_request_info
  28
  29 try:
  30     import simplejson as _json
  31 except ImportError:
  32     import json as _json
  33
  34
  35 class IndicoJSONEncoder(_json.JSONEncoder):
  36     """
  37     Custom JSON encoder that supports more types
  38      * datetime objects
  39      * PersistentDict
  40     """
  41     def default(self, o):
  42         if isinstance(o, _LazyString):
  43             return o.value
  44         elif isinstance(o, PersistentDict):
  45             return dict(o)
  46         elif isinstance(o, datetime):
  47             return {'date': str(o.date()), 'time': str(o.time()), 'tz': str(o.tzinfo)}
  48         elif isinstance(o, date):
  49             return str(o)
  50         return _json.JSONEncoder.default(self, o)
  51
  52
  53 def dumps(obj, **kwargs):
  54     """
  55     Simple wrapper around json.dumps()
  56     """
  57     if kwargs.pop('pretty', False):
  58         kwargs['indent'] = 4 * ' '
  59     textarea = kwargs.pop('textarea', False)
  60     ret = _json.dumps(obj, cls=IndicoJSONEncoder, **kwargs).replace('/', '\\/')
  61
  62     if textarea:
  63         return '<html><head></head><body><textarea>%s</textarea></body></html>' % ret
  64     else:
  65         return ret
  66
  67
  68 def loads(string):
  69     """
  70     Simple wrapper around json.decode()
  71     """
  72     return _json.loads(string)
  73
  74
  75 def create_json_error_answer(exception, status=200):
  76     from indico.core.config import Config
  77     from indico.core.errors import IndicoError, get_error_description
  78     if isinstance(exception, IndicoError):
  79         details = exception.toDict()
  80     else:
  81         exception_data = exception.__dict__
  82         try:
  83             _json.dumps(exception_data)
  84         except Exception:
  85             exception_data = {}
  86         details = {
  87             'code': type(exception).__name__,
  88             'type': 'noReport' if not session.user and isinstance(exception, Forbidden) else 'unknown',
  89             'message': unicode(get_error_description(exception)),
  90             'data': exception_data,
  91             'requestInfo': get_request_info(),
  92             'inner': traceback.format_exc()
  93         }
  94
  95     return current_app.response_class(dumps({
  96         'version': Config.getInstance().getVersion(),
  97         'result': None,
  98         'error': details
  99     }), mimetype='application/json', status=status)