Django 2.0

[wolnelektury.git] / src / wolnelektury / utils.py

diff --git a/src/wolnelektury/utils.py b/src/wolnelektury/utils.py
index 2657a55..c9b1a18 100644 (file)
--- a/src/wolnelektury/utils.py
+++ b/src/wolnelektury/utils.py
@@ -1,26 +1,28 @@
-# -*- coding: utf-8 -*-
 # This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later.
 # Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
 #
 import codecs
 import csv
-import cStringIO
+from functools import wraps
+from inspect import getargspec
+from io import BytesIO
 import json
 import os
-from functools import wraps
-
 import pytz
-from inspect import getargspec
-
 import re
+
+from django.conf import settings
+from django.core.cache import cache
 from django.core.mail import send_mail
 from django.http import HttpResponse
-from django.template import RequestContext
 from django.template.loader import render_to_string
 from django.utils import timezone
+from django.utils.translation import get_language
 from django.conf import settings
+from django.utils.safestring import mark_safe
 from django.utils.translation import ugettext
 
+
 tz = pytz.timezone(settings.TIME_ZONE)
 
 
@@ -41,7 +43,7 @@ def makedirs(path):
 
 def stringify_keys(dictionary):
     return dict((keyword.encode('ascii'), value)
-                for keyword, value in dictionary.iteritems())
+                for keyword, value in dictionary.items())
 
 
 def json_encode(obj, sort_keys=True, ensure_ascii=False):
@@ -88,11 +90,11 @@ def ajax(login_required=False, method=None, template=None, permission_required=N
                 if request_params:
                     request_params = dict(
                         (key, json_decode_fallback(value))
-                        for key, value in request_params.iteritems()
+                        for key, value in request_params.items()
                         if fun_kwargs or key in fun_params)
                     kwargs.update(stringify_keys(request_params))
                 res = None
-                if login_required and not request.user.is_authenticated():
+                if login_required and not request.user.is_authenticated:
                     res = {'result': 'logout'}
                 if (permission_required and
                         not request.user.has_perm(permission_required)):
@@ -101,7 +103,7 @@ def ajax(login_required=False, method=None, template=None, permission_required=N
                 try:
                     res = fun(request, **kwargs)
                     if res and template:
-                        res = {'html': render_to_string(template, res, RequestContext(request))}
+                        res = {'html': render_to_string(template, res, request=request)}
                 except AjaxError as e:
                     res = {'result': e.args[0]}
             if 'result' not in res:
@@ -130,7 +132,7 @@ class UnicodeCSVWriter(object):
 
     def __init__(self, f, dialect=csv.excel, encoding="utf-8", **kwds):
         # Redirect output to a queue
-        self.queue = cStringIO.StringIO()
+        self.queue = BytesIO()
         self.writer = csv.writer(self.queue, dialect=dialect, **kwds)
         self.stream = f
         self.encoder = codecs.getincrementalencoder(encoding)()
@@ -166,3 +168,42 @@ def is_crawler(request):
         return True
     user_agent = user_agent.lower()
     return any(bot_bit in user_agent for bot_bit in BOT_BITS)
+
+
+def get_cached_render_key(instance, property_name, language=None):
+    if language is None:
+        language = get_language()
+    return 'cached_render:%s.%s:%s:%s' % (
+            type(instance).__name__,
+            property_name,
+            instance.pk,
+            language
+        )
+
+
+def cached_render(template_name, timeout=24 * 60 * 60):
+    def decorator(method):
+        @wraps(method)
+        def wrapper(self):
+            key = get_cached_render_key(self, method.__name__)
+            content = cache.get(key)
+            if content is None:
+                context = method(self)
+                content = render_to_string(template_name, context)
+                cache.set(key, str(content), timeout=timeout)
+            else:
+                content = mark_safe(content)
+            return content
+        return wrapper
+    return decorator
+
+
+def clear_cached_renders(bound_method):
+    for lc, ln in settings.LANGUAGES:
+        cache.delete(
+            get_cached_render_key(
+                bound_method.__self__,
+                bound_method.__name__,
+                lc
+            )
+        )