src/wolnelektury/utils.py

   1 # This file is part of Wolne Lektury, licensed under GNU Affero GPLv3 or later.
   2 # Copyright © Fundacja Wolne Lektury. See NOTICE for more information.
   3 #
   4 import codecs
   5 import csv
   6 from functools import wraps
   7 from io import BytesIO
   8 import os
   9 import re
  10
  11 from django.conf import settings
  12 from django.contrib import admin
  13 from django.core.cache import cache
  14 from django.core.mail import send_mail
  15 from django.template.loader import render_to_string
  16 from django.utils.translation import get_language
  17 from django.conf import settings
  18 from django.utils.safestring import mark_safe
  19
  20
  21 def utc_for_js(dt):
  22     return dt.strftime('%Y/%m/%d %H:%M:%S UTC')
  23
  24
  25 def makedirs(path):
  26     if not os.path.isdir(path):
  27         os.makedirs(path)
  28
  29
  30 def send_noreply_mail(subject, message, recipient_list, **kwargs):
  31     send_mail(
  32         '[WolneLektury] ' + subject,
  33         message + "\n\n-- \nWiadomość wysłana automatycznie. Prosimy nie odpowiadać.",
  34         'no-reply@wolnelektury.pl', recipient_list, **kwargs)
  35
  36
  37 # source: https://docs.python.org/2/library/csv.html#examples
  38 class UnicodeCSVWriter(object):
  39     """
  40     A CSV writer which will write rows to CSV file "f",
  41     which is encoded in the given encoding.
  42     """
  43
  44     def __init__(self, f, dialect=csv.excel, encoding="utf-8", **kwds):
  45         # Redirect output to a queue
  46         self.queue = BytesIO()
  47         self.writer = csv.writer(self.queue, dialect=dialect, **kwds)
  48         self.stream = f
  49         self.encoder = codecs.getincrementalencoder(encoding)()
  50
  51     def writerow(self, row):
  52         self.writer.writerow([s.encode("utf-8") for s in row])
  53         # Fetch UTF-8 output from the queue ...
  54         data = self.queue.getvalue()
  55         data = data.decode("utf-8")
  56         # ... and reencode it into the target encoding
  57         data = self.encoder.encode(data)
  58         # write to the target stream
  59         self.stream.write(data)
  60         # empty queue
  61         self.queue.truncate(0)
  62
  63     def writerows(self, rows):
  64         for row in rows:
  65             self.writerow(row)
  66
  67
  68 # the original re.escape messes with unicode
  69 def re_escape(s):
  70     return re.sub(r"[(){}\[\].*?|^$\\+-]", r"\\\g<0>", s)
  71
  72
  73 def get_cached_render_key(instance, property_name, language=None):
  74     if language is None:
  75         language = get_language()
  76     return 'cached_render:%s.%s:%s:%s' % (
  77             type(instance).__name__,
  78             property_name,
  79             instance.pk,
  80             language
  81         )
  82
  83
  84 def cached_render(template_name, timeout=24 * 60 * 60):
  85     def decorator(method):
  86         @wraps(method)
  87         def wrapper(self):
  88             key = get_cached_render_key(self, method.__name__)
  89             content = cache.get(key)
  90             if content is None:
  91                 context = method(self)
  92                 content = render_to_string(template_name, context)
  93                 cache.set(key, str(content), timeout=timeout)
  94             else:
  95                 content = mark_safe(content)
  96             return content
  97         return wrapper
  98     return decorator
  99
 100
 101 def clear_cached_renders(bound_method):
 102     for lc, ln in settings.LANGUAGES:
 103         cache.delete(
 104             get_cached_render_key(
 105                 bound_method.__self__,
 106                 bound_method.__name__,
 107                 lc
 108             )
 109         )
 110
 111
 112 class YesNoFilter(admin.SimpleListFilter):
 113     def lookups(self, request, model_admin):
 114         return (
 115             ('yes', 'Tak'),
 116             ('no', 'Nie'),
 117         )
 118
 119     def queryset(self, request, queryset):
 120         if self.value() == 'yes':
 121             return queryset.filter(self.q)
 122         elif self.value() == 'no':
 123             return queryset.exclude(self.q)
 124
 125
 126 def is_ajax(request):
 127     return request.headers.get('x-requested-with') == 'XMLHttpRequest'