Merge pull request #860 from avaris/strftime-jinja-filter

Fix for #701: adds a 'strftime' jinja fiter that uses LOCALE

.travis.yml

@@ -5,6 +5,7 @@ python:
 before_install:
  - sudo apt-get update -qq
  - sudo apt-get install -qq --no-install-recommends asciidoc
+ - sudo locale-gen fr_FR.UTF-8 tr_TR.UTF-8
 install:
     - if [[ $TRAVIS_PYTHON_VERSION == '2.7' ]]; then ln -s /usr/share/asciidoc/asciidocapi.py ~/virtualenv/python2.7/lib/python2.7/site-packages/; fi
     - pip install mock --use-mirrors

docs/themes.rst

@@ -78,7 +78,7 @@ Sorting
 -------
 
 URL wrappers (currently categories, tags, and authors), have
-comparison methods that allow them to be easily sorted by name:
+comparison methods that allow them to be easily sorted by name::
 
     {% for tag, articles in tags|sort %}
 
@@ -87,6 +87,24 @@ command`__ has a number of options.
 
 __ http://jinja.pocoo.org/docs/templates/#sort
 
+
+Date Formatting
+---------------
+
+Pelican formats the date with according to your settings and locale 
+(``DATE_FORMATS``/``DEFAULT_DATE_FORMAT``) and provides a 
+``locale_date`` attribute. On the other hand, ``date`` attribute will
+be a `datetime`_ object. If you need custom formatting for a date 
+different than your settings, use the Jinja filter ``strftime`` 
+that comes with Pelican. Usage is same as Python `strftime`_ format, 
+but the filter will do the right thing and format your date according
+to the locale given in your settings::
+
+    {{ article.date|strftime('%d %B %Y') }}
+
+.. _datetime: http://docs.python.org/2/library/datetime.html#datetime-objects
+.. _strftime: http://docs.python.org/2/library/datetime.html#strftime-strptime-behavior
+
 index.html
 ----------
 

pelican/generators.py

@@ -23,7 +23,7 @@ from pelican.contents import (
         Article, Page, Category, Static, is_valid_content
 )
 from pelican.readers import read_file
-from pelican.utils import copy, process_translations, mkdir_p
+from pelican.utils import copy, process_translations, mkdir_p, DateFormatter
 from pelican import signals
 import pelican.utils
 
@@ -65,6 +65,9 @@ class Generator(object):
 
         logger.debug('template list: {0}'.format(self.env.list_templates()))
 
+        # provide utils.strftime as a jinja filter
+        self.env.filters.update({'strftime': DateFormatter()})
+
         # get custom Jinja filters from user settings
         custom_filters = self.settings.get('JINJA_FILTERS', {})
         self.env.filters.update(custom_filters)

pelican/tests/test_utils.py

@@ -7,7 +7,11 @@ import datetime
 import time
 import locale
 from sys import platform
+from tempfile import mkdtemp
 
+from pelican.generators import TemplatePagesGenerator
+from pelican.writers import Writer
+from pelican.settings import read_settings
 from pelican import utils
 from .support import get_article, LoggedTestCase, locale_available, unittest
 
@@ -283,3 +287,84 @@ class TestUtils(LoggedTestCase):
 
         # restore locale back
         locale.setlocale(locale.LC_TIME, old_locale)
+
+
+class TestDateFormatter(unittest.TestCase):
+    '''Tests that the output of DateFormatter jinja filter is same as
+    utils.strftime'''
+
+    def setUp(self):
+        # prepare a temp content and output folder
+        self.temp_content = mkdtemp(prefix='pelicantests.')
+        self.temp_output = mkdtemp(prefix='pelicantests.')
+
+        # prepare a template file
+        template_dir = os.path.join(self.temp_content, 'template')
+        template_path = os.path.join(template_dir, 'source.html')
+        os.makedirs(template_dir)
+        with open(template_path, 'w') as template_file:
+            template_file.write('date = {{ date|strftime("%A, %d %B %Y") }}')
+        self.date = datetime.date(2012, 8, 29)
+
+
+    def tearDown(self):
+        shutil.rmtree(self.temp_content)
+        shutil.rmtree(self.temp_output)
+        # reset locale to default
+        locale.setlocale(locale.LC_ALL, '')
+
+
+    @unittest.skipUnless(locale_available('fr_FR.UTF-8') or
+                         locale_available('French'),
+                         'French locale needed')
+    def test_french_locale(self):
+        settings = read_settings(
+            override = {'LOCALE': locale.normalize('fr_FR.UTF-8'),
+                        'TEMPLATE_PAGES': {'template/source.html':
+                                           'generated/file.html'}})
+
+        generator = TemplatePagesGenerator({'date': self.date}, settings,
+                self.temp_content, '', self.temp_output, None)
+        generator.env.filters.update({'strftime': utils.DateFormatter()})
+
+        writer = Writer(self.temp_output, settings=settings)
+        generator.generate_output(writer)
+
+        output_path = os.path.join(
+                self.temp_output, 'generated', 'file.html')
+
+        # output file has been generated
+        self.assertTrue(os.path.exists(output_path))
+
+        # output content is correct
+        with utils.pelican_open(output_path) as output_file:
+            self.assertEqual(output_file,
+                             utils.strftime(self.date, 'date = %A, %d %B %Y'))
+
+
+    @unittest.skipUnless(locale_available('tr_TR.UTF-8') or
+                         locale_available('Turkish'),
+                         'Turkish locale needed')
+    def test_turkish_locale(self):
+        settings = read_settings(
+            override = {'LOCALE': locale.normalize('tr_TR.UTF-8'),
+                        'TEMPLATE_PAGES': {'template/source.html':
+                                           'generated/file.html'}})
+
+        generator = TemplatePagesGenerator({'date': self.date}, settings,
+                self.temp_content, '', self.temp_output, None)
+        generator.env.filters.update({'strftime': utils.DateFormatter()})
+
+        writer = Writer(self.temp_output, settings=settings)
+        generator.generate_output(writer)
+
+        output_path = os.path.join(
+                self.temp_output, 'generated', 'file.html')
+
+        # output file has been generated
+        self.assertTrue(os.path.exists(output_path))
+
+        # output content is correct
+        with utils.pelican_open(output_path) as output_file:
+            self.assertEqual(output_file,
+                             utils.strftime(self.date, 'date = %A, %d %B %Y'))

pelican/utils.py

@@ -65,6 +65,26 @@ def strftime(date, date_format):
     return template % tuple(formatted_candidates)
 
 
+class DateFormatter(object):
+    '''A date formatter object used as a jinja filter
+    
+    Uses the `strftime` implementation and makes sure jinja uses the locale 
+    defined in LOCALE setting
+    '''
+    
+    def __init__(self):
+        self.locale = locale.setlocale(locale.LC_TIME)
+
+    def __call__(self, date, date_format):
+        old_locale = locale.setlocale(locale.LC_TIME)
+        locale.setlocale(locale.LC_TIME, self.locale)
+
+        formatted = strftime(date, date_format)
+
+        locale.setlocale(locale.LC_TIME, old_locale)
+        return formatted
+
+
 def python_2_unicode_compatible(klass):
     """
     A decorator that defines __unicode__ and __str__ methods under Python 2.