Support ordering pages and articles when iterating in templates.

docs/settings.rst

@@ -260,11 +260,19 @@ posts for the month at ``posts/2011/Aug/index.html``.
     arrive at an appropriate archive of posts, without having to specify
     a page name.
 
-======================================================  ========================================================
+======================================================  ==============================================================
 Setting name (followed by default value, if any)        What does it do?
-======================================================  ========================================================
+======================================================  ==============================================================
 ``ARTICLE_URL = '{slug}.html'``                         The URL to refer to an article.
 ``ARTICLE_SAVE_AS = '{slug}.html'``                     The place where we will save an article.
+``ARTICLE_ORDER_BY = 'slug'``                           The metadata attribute used to sort articles. By default,
+                                                        the ``articles_page.object_list`` template variable is
+                                                        ordered by slug. If you modify this, make sure all
+                                                        articles contain the attribute you specify. You can also
+                                                        specify a "sorting" function of one argument that is used
+                                                        to extract a comparison key from each article. For example,
+                                                        sorting by title without using the built-in functionality
+                                                        would use the function ``operator.attrgetter('title')``.
 ``ARTICLE_LANG_URL = '{slug}-{lang}.html'``             The URL to refer to an article which doesn't use the
                                                         default language.
 ``ARTICLE_LANG_SAVE_AS = '{slug}-{lang}.html'``         The place where we will save an article which
@@ -279,6 +287,17 @@ Setting name (followed by default value, if any)        What does it do?
 ``PAGE_SAVE_AS = 'pages/{slug}.html'``                  The location we will save the page. This value has to be
                                                         the same as PAGE_URL or you need to use a rewrite in
                                                         your server config.
+
+``PAGE_ORDER_BY = 'basename'``                          The metadata attribute used to sort pages. By default
+                                                        the ``PAGES`` template variable is ordered by basename
+                                                        (i.e., path not included). Note that the option ``'basename'``
+                                                        is a special option supported in the source code. If
+                                                        you modify this setting, make sure all pages contain
+                                                        the attribute you specify. You can also specify a "sorting"
+                                                        function of one argument that is used to extract a comparison
+                                                        key from each page. For example, the basename function looks
+                                                        similar to
+                                                        ``lambda x: os.path.basename(getattr(x, 'source_path', ''))``.
 ``PAGE_LANG_URL = 'pages/{slug}-{lang}.html'``          The URL we will use to link to a page which doesn't
                                                         use the default language.
 ``PAGE_LANG_SAVE_AS = 'pages/{slug}-{lang}.html'``      The location we will save the page which doesn't
@@ -296,7 +315,7 @@ Setting name (followed by default value, if any)        What does it do?
                                                         non-alphanumerics when generating slugs. Specified
                                                         as a list of 2-tuples of ``(from, to)`` which are
                                                         applied in order.
-======================================================  ========================================================
+======================================================  ==============================================================
 
 .. note::
 

pelican/generators.py

@@ -501,7 +501,8 @@ def generate_context(self):
                                (repr(article.status),
                                 repr(f)))
 
-        self.articles, self.translations = process_translations(all_articles)
+        self.articles, self.translations = process_translations(all_articles,
+                order_by=self.settings['ARTICLE_ORDER_BY'])
         self.drafts, self.drafts_translations = \
             process_translations(all_drafts)
 
@@ -618,7 +619,8 @@ def generate_context(self):
                                (repr(page.status),
                                 repr(f)))
 
-        self.pages, self.translations = process_translations(all_pages)
+        self.pages, self.translations = process_translations(all_pages,
+                order_by=self.settings['PAGE_ORDER_BY'])
         self.hidden_pages, self.hidden_translations = (
             process_translations(hidden_pages))
 

pelican/settings.py

@@ -61,6 +61,7 @@
     'OUTPUT_RETENTION': (),
     'ARTICLE_URL': '{slug}.html',
     'ARTICLE_SAVE_AS': '{slug}.html',
+    'ARTICLE_ORDER_BY': 'slug',
     'ARTICLE_LANG_URL': '{slug}-{lang}.html',
     'ARTICLE_LANG_SAVE_AS': '{slug}-{lang}.html',
     'DRAFT_URL': 'drafts/{slug}.html',
@@ -69,6 +70,7 @@
     'DRAFT_LANG_SAVE_AS': os.path.join('drafts', '{slug}-{lang}.html'),
     'PAGE_URL': 'pages/{slug}.html',
     'PAGE_SAVE_AS': os.path.join('pages', '{slug}.html'),
+    'PAGE_ORDER_BY': 'basename',
     'PAGE_LANG_URL': 'pages/{slug}-{lang}.html',
     'PAGE_LANG_SAVE_AS': os.path.join('pages', '{slug}-{lang}.html'),
     'STATIC_URL': '{path}',

pelican/tests/TestPages/page_used_for_sorting_test.rst

@@ -0,0 +1,6 @@
+A Page (Test) for sorting
+#########################
+
+:slug: zzzz
+
+When using title, should be first. When using slug, should be last.

pelican/tests/test_generators.py

@@ -7,6 +7,7 @@
     from unittest.mock import MagicMock
 except ImportError:
     from mock import MagicMock
+from operator import itemgetter
 from shutil import rmtree
 from tempfile import mkdtemp
 
@@ -55,15 +56,19 @@ def setUpClass(cls):
             context=settings.copy(), settings=settings,
             path=CONTENT_DIR, theme=settings['THEME'], output_path=None)
         cls.generator.generate_context()
-        cls.articles = [[page.title, page.status, page.category.name,
-                         page.template] for page in cls.generator.articles]
+        cls.articles = cls.distill_articles(cls.generator.articles)
 
     def setUp(self):
         self.temp_cache = mkdtemp(prefix='pelican_cache.')
 
     def tearDown(self):
         rmtree(self.temp_cache)
 
+    @staticmethod
+    def distill_articles(articles):
+        return [[article.title, article.status, article.category.name,
+                 article.template] for article in articles]
+
     def test_generate_feeds(self):
         settings = get_settings()
         settings['CACHE_PATH'] = self.temp_cache
@@ -388,7 +393,8 @@ def test_generate_context(self):
             ['This is a test page', 'published', 'page'],
             ['This is a markdown test page', 'published', 'page'],
             ['This is a test page with a preset template', 'published',
-             'custom']
+             'custom'],
+            ['A Page (Test) for sorting', 'published', 'page'],
         ]
         hidden_pages_expected = [
             ['This is a test hidden page', 'hidden', 'page'],
@@ -466,6 +472,42 @@ def test_ignore_cache(self):
         generator.generate_context()
         generator.readers.read_file.assert_called_count == orig_call_count
 
+    def test_generate_sorted(self):
+        settings = get_settings(filenames={})
+        settings['PAGE_DIR'] = 'TestPages'  # relative to CUR_DIR
+        settings['DEFAULT_DATE'] = (1970, 1, 1)
+
+        # default sort (filename)
+        pages_expected_sorted_by_filename = [
+            ['This is a test page', 'published', 'page'],
+            ['This is a markdown test page', 'published', 'page'],
+            ['A Page (Test) for sorting', 'published', 'page'],
+            ['This is a test page with a preset template', 'published',
+             'custom'],
+        ]
+        generator = PagesGenerator(
+            context=settings.copy(), settings=settings,
+            path=CUR_DIR, theme=settings['THEME'], output_path=None)
+        generator.generate_context()
+        pages = self.distill_pages(generator.pages)
+        self.assertEqual(pages_expected_sorted_by_filename, pages)
+
+        # sort by title
+        pages_expected_sorted_by_title = [
+            ['A Page (Test) for sorting', 'published', 'page'],
+            ['This is a markdown test page', 'published', 'page'],
+            ['This is a test page', 'published', 'page'],
+            ['This is a test page with a preset template', 'published',
+             'custom'],
+        ]
+        settings['PAGE_ORDER_BY'] = 'title'
+        generator = PagesGenerator(
+            context=settings.copy(), settings=settings,
+            path=CUR_DIR, theme=settings['THEME'], output_path=None)
+        generator.generate_context()
+        pages = self.distill_pages(generator.pages)
+        self.assertEqual(pages_expected_sorted_by_title, pages)
+
 
 class TestTemplatePagesGenerator(unittest.TestCase):
 

pelican/utils.py

@@ -400,7 +400,7 @@ def truncate_html_words(s, num, end_text='...'):
     return out
 
 
-def process_translations(content_list):
+def process_translations(content_list, order_by=None):
     """ Finds translation and returns them.
 
     Returns a tuple with two lists (index, translations).  Index list includes
@@ -410,6 +410,14 @@ def process_translations(content_list):
     the same slug have that metadata.
 
     For each content_list item, sets the 'translations' attribute.
+
+    order_by can be a string of an attribute or sorting function. If order_by
+    is defined, content will be ordered by that attribute or sorting function.
+    By default, content is ordered by slug.
+
+    Different content types can have default order_by attributes defined
+    in settings, e.g. PAGES_ORDER_BY='sort-order', in which case `sort-order`
+    should be a defined metadata attribute in each page.
     """
     content_list.sort(key=attrgetter('slug'))
     grouped_by_slugs = groupby(content_list, attrgetter('slug'))
@@ -455,6 +463,23 @@ def process_translations(content_list):
         translations.extend([x for x in items if x not in default_lang_items])
         for a in items:
             a.translations = [x for x in items if x != a]
+
+    if order_by:
+        if callable(order_by):
+            try:
+                index.sort(key=order_by)
+            except Exception:
+                logger.error('Error sorting with function {}'.format(order_by))
+        elif order_by == 'basename':
+            index.sort(key=lambda x: os.path.basename(x.source_path or ''))
+        elif order_by != 'slug':
+            try:
+                index.sort(key=attrgetter(order_by))
+            except AttributeError:
+                error_msg = ('There is no "{}" attribute in the item metadata.'
+                             'Defaulting to slug order.')
+                logger.warning(error_msg.format(order_by))
+
     return index, translations