From a88bb7caf3b09d87ab57c976d732ca75246d8f32 Mon Sep 17 00:00:00 2001
From: Chris Dodge <cdodge@edx.org>
Date: Wed, 17 Oct 2012 16:08:16 -0400
Subject: [PATCH 1/2] hide 'View Live' button if no units have been published

---
 cms/djangoapps/contentstore/views.py | 12 ++++++++++--
 cms/templates/edit_subsection.html   |  2 ++
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/cms/djangoapps/contentstore/views.py b/cms/djangoapps/contentstore/views.py
index 28b1742621..638db228cd 100644
--- a/cms/djangoapps/contentstore/views.py
+++ b/cms/djangoapps/contentstore/views.py
@@ -55,7 +55,7 @@ from cache_toolbox.core import set_cached_content, get_cached_content, del_cache
 from auth.authz import is_user_in_course_group_role, get_users_in_course_group_by_role
 from auth.authz import get_user_by_email, add_user_to_course_group, remove_user_from_course_group
 from auth.authz import INSTRUCTOR_ROLE_NAME, STAFF_ROLE_NAME, create_all_course_groups
-from .utils import get_course_location_for_item, get_lms_link_for_item, compute_unit_state, get_date_display
+from .utils import get_course_location_for_item, get_lms_link_for_item, compute_unit_state, get_date_display, UnitState
 
 from xmodule.templates import all_templates
 from xmodule.modulestore.xml_importer import import_from_xml
@@ -214,6 +214,13 @@ def edit_subsection(request, location):
     policy_metadata = dict((key,value) for key, value in item.metadata.iteritems() 
         if key not in ['display_name', 'start', 'due', 'format'] and key not in item.system_metadata_fields)
 
+    can_view_live = False
+    for unit in item.get_children():
+        state = compute_unit_state(unit)
+        if state == UnitState.public or state == UnitState.draft:
+            can_view_live = True
+            break
+
     return render_to_response('edit_subsection.html',
                               {'subsection': item,
                                'context_course': course,
@@ -221,7 +228,8 @@ def edit_subsection(request, location):
                                'lms_link': lms_link,
                                'preview_link': preview_link,
                                'parent_item': parent,
-                               'policy_metadata' : policy_metadata
+                               'policy_metadata' : policy_metadata,
+                               'can_view_live' : can_view_live
                                })
 
 
diff --git a/cms/templates/edit_subsection.html b/cms/templates/edit_subsection.html
index 15753e9720..4eb8210816 100644
--- a/cms/templates/edit_subsection.html
+++ b/cms/templates/edit_subsection.html
@@ -95,7 +95,9 @@
     <div class="row unit-actions">
       <a href="#" class="save-button save-subsection" data-id="${subsection.location}">Save</a>
       <a href="${preview_link}" target="_blank" class="preview-button">Preview Drafts</a>
+      %if can_view_live:
       <a href="${lms_link}" target="_blank" class="preview-button">View Live</a>
+      %endif
     </div>
       </div>
     </div>

From 1a6845b07fcea7b474243956c58aa87350ecff57 Mon Sep 17 00:00:00 2001
From: Chris Dodge <cdodge@edx.org>
Date: Wed, 17 Oct 2012 16:17:52 -0400
Subject: [PATCH 2/2] optimize slightly, allow caller to pass in the list of
 units in a subsection, so we don't have to refetch

---
 cms/djangoapps/contentstore/views.py | 4 +++-
 cms/templates/edit_subsection.html   | 2 +-
 cms/templates/widgets/units.html     | 8 ++++++--
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/cms/djangoapps/contentstore/views.py b/cms/djangoapps/contentstore/views.py
index 638db228cd..1f206539f3 100644
--- a/cms/djangoapps/contentstore/views.py
+++ b/cms/djangoapps/contentstore/views.py
@@ -215,7 +215,8 @@ def edit_subsection(request, location):
         if key not in ['display_name', 'start', 'due', 'format'] and key not in item.system_metadata_fields)
 
     can_view_live = False
-    for unit in item.get_children():
+    subsection_units = item.get_children()
+    for unit in subsection_units:
         state = compute_unit_state(unit)
         if state == UnitState.public or state == UnitState.draft:
             can_view_live = True
@@ -229,6 +230,7 @@ def edit_subsection(request, location):
                                'preview_link': preview_link,
                                'parent_item': parent,
                                'policy_metadata' : policy_metadata,
+                               'subsection_units' : subsection_units,
                                'can_view_live' : can_view_live
                                })
 
diff --git a/cms/templates/edit_subsection.html b/cms/templates/edit_subsection.html
index 4eb8210816..4c2a7d7516 100644
--- a/cms/templates/edit_subsection.html
+++ b/cms/templates/edit_subsection.html
@@ -29,7 +29,7 @@
         </div>
         <div class="unit-list">
           <label>Units:</label>
-          ${units.enum_units(subsection)}
+          ${units.enum_units(subsection, subsection_units=subsection_units)}
         </div>
         <div>
           <label>Policy:</label>
diff --git a/cms/templates/widgets/units.html b/cms/templates/widgets/units.html
index fe955baafe..df632ac3d8 100644
--- a/cms/templates/widgets/units.html
+++ b/cms/templates/widgets/units.html
@@ -4,9 +4,13 @@
 <!--
 This def will enumerate through a passed in subsection and list all of the units
 -->
-<%def name="enum_units(subsection, actions=True, selected=None, sortable=True)">
+<%def name="enum_units(subsection, actions=True, selected=None, sortable=True, subsection_units=None)">
 <ol ${'class="sortable-unit-list"' if sortable else ''} data-subsection-id="${subsection.location}">
-  % for unit in subsection.get_children():
+  <%
+    if subsection_units is None:
+      subsection_units = subsection.get_children()
+  %>
+  % for unit in subsection_units:
   <li class="leaf unit" data-id="${unit.location}">
     <%
       unit_state = compute_unit_state(unit)