X-Git-Url: https://git.mdrn.pl/wolnelektury.git/blobdiff_plain/2856ae6ae36213ca7997366e0c7790e3c855e62f..85800bcf632ba3e027667835b08f8e0dc5ab6177:/apps/catalogue/utils.py

diff --git a/apps/catalogue/utils.py b/apps/catalogue/utils.py
index b023f1a2f..fd74c9498 100644
--- a/apps/catalogue/utils.py
+++ b/apps/catalogue/utils.py
@@ -38,8 +38,12 @@ def get_random_hash(seed):
     return urlsafe_b64encode(sha_digest).replace('=', '').replace('_', '-').lower()
 
 
-def split_tags(tags):
-    result = {}
+def split_tags(tags, initial=None):
+    if initial is None:
+        result = {}
+    else:
+        result = initial
+    
     for tag in tags:
         result.setdefault(tag.category, []).append(tag)
     return result
@@ -188,6 +192,52 @@ class MultiQuerySet(object):
                     stop = total_len - len(items)
                     continue
 
+class SortedMultiQuerySet(MultiQuerySet):
+    def __init__(self, *args, **kwargs):
+        self.order_by = kwargs.pop('order_by', None)
+        self.sortfn = kwargs.pop('sortfn', None)
+        if self.order_by is not None:
+            self.sortfn = lambda a, b: cmp(getattr(a, self.order_by), 
+                                           getattr(b, self.order_by))
+        super(SortedMultiQuerySet, self).__init__(*args, **kwargs)
+
+    def __getitem__(self, item):
+        sort_heads = [0] * len(self.querysets)
+        try:
+            indices = (offset, stop, step) = item.indices(self.count())
+        except AttributeError:
+            # it's not a slice - make it one
+            return self[item : item + 1][0]
+        items = []
+        total_len = stop - offset
+        skipped = 0
+        i_s = range(len(sort_heads))
+
+        while len(items) < total_len:
+            candidate = None
+            for i in i_s:
+                def get_next():
+                    return self.querysets[i][sort_heads[i]]
+                try:
+                    if candidate is None:
+                        candidate = get_next()
+                    else:
+                        competitor = get_next()
+                        if self.sortfn(candidate, competitor) > 0:
+                            candidate = competitor
+                except IndexError:
+                    continue # continue next sort_head
+                sort_heads[i] += 1
+            # we have no more elements:
+            if candidate is None:
+                break
+            if skipped < offset:
+                skipped += 1
+                continue # continue next item
+            items.append(candidate)
+        
+        return items
+
 
 def truncate_html_words(s, num, end_text='...'):
     """Truncates HTML to a certain number of words (not counting tags and
@@ -317,7 +367,7 @@ This can sometimes occupy lots of memory, so trim it here a bit.
 
 def related_tag_name(tag_info, language=None):
     return tag_info.get("name_%s" % (language or get_language()),
-        tag_info.get("name_%s" % settings.LANGUAGE_CODE))
+        tag_info.get("name_%s" % settings.LANGUAGE_CODE, ""))
 
 
 def delete_from_cache_by_language(cache, key_template):