src/wolnelektury/utils.py

   1 # -*- coding: utf-8 -*-
   2 # This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later.
   3 # Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
   4 #
   5 import json
   6 import os
   7 from functools import wraps
   8
   9 import pytz
  10 from inspect import getargspec
  11
  12 from django.core.mail import send_mail
  13 from django.http import HttpResponse
  14 from django.template import RequestContext
  15 from django.template.loader import render_to_string
  16 from django.utils import timezone
  17 from django.conf import settings
  18 from django.utils.translation import ugettext
  19
  20 tz = pytz.timezone(settings.TIME_ZONE)
  21
  22
  23 def localtime_to_utc(localtime):
  24     return timezone.utc.normalize(
  25         tz.localize(localtime)
  26     )
  27
  28
  29 def utc_for_js(dt):
  30     return dt.strftime('%Y/%m/%d %H:%M:%S UTC')
  31
  32
  33 def makedirs(path):
  34     if not os.path.isdir(path):
  35         os.makedirs(path)
  36
  37
  38 def stringify_keys(dictionary):
  39     return dict((keyword.encode('ascii'), value)
  40                 for keyword, value in dictionary.iteritems())
  41
  42
  43 def json_encode(obj, sort_keys=True, ensure_ascii=False):
  44     return json.dumps(obj, sort_keys=sort_keys, ensure_ascii=ensure_ascii)
  45
  46
  47 def json_decode(obj):
  48     return json.loads(obj)
  49
  50
  51 def json_decode_fallback(value):
  52     try:
  53         return json_decode(value)
  54     except ValueError:
  55         return value
  56
  57
  58 class AjaxError(Exception):
  59     pass
  60
  61
  62 def ajax(login_required=False, method=None, template=None, permission_required=None):
  63     def decorator(fun):
  64         @wraps(fun)
  65         def ajax_view(request):
  66             kwargs = {}
  67             request_params = None
  68             if method == 'post':
  69                 request_params = request.POST
  70             elif method == 'get':
  71                 request_params = request.GET
  72             fun_params, xx, fun_kwargs, defaults = getargspec(fun)
  73             if defaults:
  74                 required_params = fun_params[1:-len(defaults)]
  75             else:
  76                 required_params = fun_params[1:]
  77             missing_params = set(required_params) - set(request_params)
  78             if missing_params:
  79                 res = {
  80                     'result': 'missing params',
  81                     'missing': ', '.join(missing_params),
  82                 }
  83             else:
  84                 if request_params:
  85                     request_params = dict(
  86                         (key, json_decode_fallback(value))
  87                         for key, value in request_params.iteritems()
  88                         if fun_kwargs or key in fun_params)
  89                     kwargs.update(stringify_keys(request_params))
  90                 res = None
  91                 if login_required and not request.user.is_authenticated():
  92                     res = {'result': 'logout'}
  93                 if (permission_required and
  94                         not request.user.has_perm(permission_required)):
  95                     res = {'result': 'access denied'}
  96             if not res:
  97                 try:
  98                     res = fun(request, **kwargs)
  99                     if res and template:
 100                         res = {'html': render_to_string(template, res, RequestContext(request))}
 101                 except AjaxError as e:
 102                     res = {'result': e.args[0]}
 103             if 'result' not in res:
 104                 res['result'] = 'ok'
 105             return HttpResponse(json_encode(res), content_type='application/json; charset=utf-8',
 106                                 status=200 if res['result'] == 'ok' else 400)
 107
 108         return ajax_view
 109
 110     return decorator
 111
 112
 113 def send_noreply_mail(subject, message, recipient_list, **kwargs):
 114     send_mail(
 115         u'[WolneLektury] ' + subject,
 116         message + u"\n\n-- \n" + ugettext(u'Message sent automatically. Please do not reply.'),
 117         'no-reply@wolnelektury.pl', recipient_list, **kwargs)