implemented multi-page display of frontpage polls

wortschlucker/src/wortschlucker.py

@@ -417,9 +417,30 @@ def base():
     return bobo.redirect(BASE_DICT["base_url"])
 
 @bobo.query('/')
-def show_frontpage():
+def show_frontpage(page=None):
     value_dict = get_default_values()
-    value_dict["polls"] = Poll.select()
+    polls = Poll.select().orderBy("-timestamp_creation")
+    # TODO: speed the filtering up by using SQL statements (see sqlobject "filter")
+    polls = [poll for poll in polls if poll.get_settings()["public"]]
+    if page is None:
+        page = 1
+    else:
+        try:
+            page = int(page)
+        except ValueError:
+            page = 1
+    page_size = 10
+    start = (page - 1) * page_size
+    if start >= len(polls):
+        start = 0
+        page = 1
+    end = start + page_size - 1
+    value_dict["polls"] = polls[start : end + 1]
+    print value_dict["polls"]
+    # show a link for the next page, if more polls are available
+    value_dict["show_next_link"] = (end + 1 < len(polls))
+    value_dict["show_previous_link"] = (start > 0)
+    value_dict["page"] = page
     return render("frontpage.html", **value_dict)
 
 def render_poll_admin(poll, add_related, del_related):