Implement album sorting

This adds an 'albums_sort_attr' configuration modeled off of the
'medias_sort_attr'.  It defaults to the existing behavior of sorting
sub-albums by directory name.  It allows sort by any metadata attribute
stored in the album metadata file.

The existing album sort test wasn't really verifying album sorting
behavior, so I just re-wrote the whole thing to include tests for the
old behavior and new.

This should resolve issue #121

sigal/gallery.py

@@ -221,6 +221,7 @@ class Album(UnicodeMixin):
         self.name = path.split(os.path.sep)[-1]
         self.gallery = gallery
         self.settings = settings
+        self.subdirs = dirnames
         self.output_file = settings['output_filename']
         self._thumbnail = None
 
@@ -240,10 +241,6 @@ class Album(UnicodeMixin):
         self.index_url = url_from_path(os.path.relpath(
             settings['destination'], self.dst_path)) + '/' + self.url_ext
 
-        # sort sub-albums
-        dirnames.sort(key=strxfrm, reverse=settings['albums_sort_reverse'])
-        self.subdirs = dirnames
-
         #: List of all medias in the album (:class:`~sigal.gallery.Image` and
         #: :class:`~sigal.gallery.Video`).
         self.medias = medias = []
@@ -313,6 +310,20 @@ class Album(UnicodeMixin):
             self.orig_path = join(self.dst_path, self.settings['orig_dir'])
             check_or_create_dir(self.orig_path)
 
+    def sort_subdirs(self, albums_sort_attr):
+        if self.subdirs:
+            if albums_sort_attr:
+                root_path = self.path if self.path != '.' else ''
+                key = lambda s: strxfrm(getattr(
+                    self.gallery.albums[join(root_path, s)], albums_sort_attr))
+            else:
+                key = strxfrm
+
+            self.subdirs.sort(key=key,
+                              reverse=self.settings['albums_sort_reverse'])
+
+        signals.albums_sorted.send(self)
+
     def sort_medias(self, medias_sort_attr):
         if self.medias:
             if medias_sort_attr == 'date':
@@ -525,6 +536,11 @@ class Gallery(object):
                 album.create_output_directories()
                 albums[relpath] = album
 
+        with progressbar(albums.values(), label="Sorting albums",
+                         file=self.progressbar_target) as progress_albums:
+            for album in progress_albums:
+                album.sort_subdirs(settings['albums_sort_attr'])
+
         with progressbar(albums.values(), label="Sorting media",
                          file=self.progressbar_target) as progress_albums:
             for album in progress_albums:

sigal/settings.py

@@ -31,6 +31,7 @@ from .compat import PY2, text_type
 
 
 _DEFAULT_CONFIG = {
+    'albums_sort_attr': 'name',
     'albums_sort_reverse': False,
     'autorotate_images': True,
     'colorbox_column_size': 4,

sigal/signals.py

@@ -8,4 +8,5 @@ album_initialized = signal('album_initialized')
 gallery_initialized = signal('gallery_initialized')
 gallery_build = signal('gallery_build')
 media_initialized = signal('media_initialized')
+albums_sorted = signal('albums_sorted')
 medias_sorted = signal('medias_sorted')

sigal/templates/sigal.conf.py

@@ -101,6 +101,9 @@ thumb_size = (280, 210)
 # Use symbolic links instead of copying the original images
 # orig_link = False
 
+# Attribute of Album objects which is used to sort medias (eg 'title').
+# albums_sort_attr = 'name'
+
 # Reverse sort for albums
 # albums_sort_reverse = False
 

tests/sample/pictures/dir1/test3/index.md

@@ -0,0 +1 @@
+Title: 01 First title alphabetically

tests/test_gallery.py

@@ -15,7 +15,7 @@ REF = {
         'title': 'An example gallery',
         'name': 'dir1',
         'thumbnail': 'dir1/test1/thumbnails/11.tn.jpg',
-        'subdirs': ['test1', 'test2'],
+        'subdirs': ['test1', 'test2', 'test3'],
         'medias': [],
     },
     'dir1/test1': {
@@ -34,6 +34,13 @@ REF = {
         'subdirs': [],
         'medias': ['21.jpg', '22.jpg', 'archlinux-kiss-1024x640.png'],
     },
+    'dir1/test3': {
+        'title': '01 First title alphabetically',
+        'name': 'test3',
+        'thumbnail': 'test3/thumbnails/3.tn.jpg',
+        'subdirs': [],
+        'medias': ['3.jpg'],
+    },
     'dir2': {
         'title': 'Another example gallery with a very long name',
         'name': 'dir2',
@@ -165,10 +172,29 @@ def test_album_medias(settings):
 def test_albums_sort(settings):
     gal = Gallery(settings, ncpu=1)
     album = REF['dir1']
+    subdirs = list(album['subdirs'])
+
+    settings['albums_sort_reverse'] = False
+    a = Album('dir1', settings, album['subdirs'], album['medias'], gal)
+    a.sort_subdirs('')
+    assert [alb.name for alb in a.albums] == subdirs
 
     settings['albums_sort_reverse'] = True
     a = Album('dir1', settings, album['subdirs'], album['medias'], gal)
-    assert [im.filename for im in a.images] == list(reversed(album['medias']))
+    a.sort_subdirs('')
+    assert [alb.name for alb in a.albums] == list(reversed(subdirs))
+
+    titles = [im.title for im in a.albums]
+    titles.sort()
+    settings['albums_sort_reverse'] = False
+    a = Album('dir1', settings, album['subdirs'], album['medias'], gal)
+    a.sort_subdirs('title')
+    assert [im.title for im in a.albums] == titles
+
+    settings['albums_sort_reverse'] = True
+    a = Album('dir1', settings, album['subdirs'], album['medias'], gal)
+    a.sort_subdirs('title')
+    assert [im.title for im in a.albums] == list(reversed(titles))
 
 
 def test_medias_sort(settings):