Show Lesson post and comments in discussion forum

 - Use trash icon instead of DELETE button
 - Sidebar to navigate between course forum and lesson forum
 - Course forum displays all the questions (posts) linked with the
 course model, and Lesson forum displays all the questions (posts)
 linked with the Lesson model.

9 files changed, 286 insertions, 125 deletions

diff --git a/yaksh/models.py b/yaksh/models.py
index 67f981e..df70fc1 100644
--- a/yaksh/models.py
+++ b/yaksh/models.py
@@ -1102,6 +1102,25 @@ class Course(models.Model):
             learning_units.extend(module.get_learning_units())
         return learning_units
 
+    def get_lesson_posts(self, user):
+        learning_units = self.get_learning_units()
+        comments = []
+        for unit in learning_units:
+            if unit.lesson is not None:
+                lesson_ct = ContentType.objects.get_for_model(unit.lesson)
+                title = unit.lesson.name
+                try:
+                    post = Post.objects.get(
+                        target_ct=lesson_ct,
+                        target_id=unit.lesson.id,
+                        active=True, title=title, creator=user
+                    )
+                except Post.DoesNotExist:
+                    post = None
+                if post is not None:
+                    comments.append(post)
+        return comments
+
     def remove_trial_modules(self):
         learning_modules = self.learning_module.all()
         for module in learning_modules:
diff --git a/yaksh/static/yaksh/css/custom.css b/yaksh/static/yaksh/css/custom.css
index 26efbed..edb9530 100644
--- a/yaksh/static/yaksh/css/custom.css
+++ b/yaksh/static/yaksh/css/custom.css
@@ -109,12 +109,49 @@ body, .dropdown-menu {
     FORUM STYLE
 ----------------------------------------------------- */
 
-.brown-light {
-    background: #f4a460;
-    padding-left: 0.3em;
-    padding-right: 0.3em;
-    padding-top: 0.2em;
-    padding-bottom: 0.2em;
+ #wrapper {
+    overflow-x: hidden;
+ }
+
+#sidebar-wrapper {
+  min-height: 100vh;
+  margin-left: -15rem;
+  -webkit-transition: margin .25s ease-out;
+  -moz-transition: margin .25s ease-out;
+  -o-transition: margin .25s ease-out;
+  transition: margin .25s ease-out;
+}
+
+#sidebar-wrapper .sidebar-heading {
+  padding: 0.875rem 1.25rem;
+  font-size: 1.2rem;
+}
+
+#sidebar-wrapper .list-group {
+  width: 15rem;
+}
+
+#page-content-wrapper {
+  min-width: 100vw;
+}
+
+#wrapper.toggled #sidebar-wrapper {
+  margin-left: 0;
+}
+
+@media (min-width: 768px) {
+  #sidebar-wrapper {
+    margin-left: 0;
+  }
+
+  #page-content-wrapper {
+    min-width: 0;
+    width: 100%;
+  }
+
+  #wrapper.toggled #sidebar-wrapper {
+    margin-left: -15rem;
+  }
 }
 
 .post_image, .comment_image {
diff --git a/yaksh/templates/yaksh/course_forum.html b/yaksh/templates/yaksh/course_forum.html
index 4724981..a9bda6f 100644
--- a/yaksh/templates/yaksh/course_forum.html
+++ b/yaksh/templates/yaksh/course_forum.html
@@ -4,124 +4,126 @@
     {{course.name}}: Discussion Forum
 {% endblock title %}
 {% block content %}
-    <div class="container">
-        <div>
-            <h2><center>{{course.name}}</center></h2>
-            <center>Discussion Forum</center>
-        </div>
-        <div class="d-flex p-2 bd-highlight">
-            <div class="col-md-4">
-                {% if moderator %}
-                    <a href="{% url 'yaksh:course_detail' course.id %}" class="btn btn-primary">
-                        <i class="fa fa-arrow-left"></i>&nbsp;Back
-                    </a>
-                {% else %}
-                    <a href="{% url 'yaksh:course_modules' course.id %}" class="btn btn-primary">
-                        <i class="fa fa-arrow-left"></i>&nbsp;Back
-                    </a>
-                {% endif %}
+    <div id="wrapper" class="d-flex">
+        {% include "yaksh/sidebar.html" %}
+        <div class="container" id="page-content-wrapper">
+            <div>
+                <h2><center>{{course.name}}</center></h2>
+                <center>Discussion Forum</center>
             </div>
-            <div class="col-md">
-                <button type="button" class="btn btn-success pull-right" data-toggle="modal" data-target="#newPostModal">
-                    <i class="fa fa-plus-circle"></i>&nbsp;New Post
-                </button>
+            <div class="d-flex p-2 bd-highlight">
+                <div class="col-md-4">
+                    {% if moderator %}
+                        <a href="{% url 'yaksh:course_detail' course.id %}" class="btn btn-primary">
+                            <i class="fa fa-arrow-left"></i>&nbsp;Back
+                        </a>
+                    {% else %}
+                        <a href="{% url 'yaksh:course_modules' course.id %}" class="btn btn-primary">
+                            <i class="fa fa-arrow-left"></i>&nbsp;Back
+                        </a>
+                    {% endif %}
+                </div>
+                <div class="col-md">
+                    <button type="button" class="btn btn-success pull-right" data-toggle="modal" data-target="#newPostModal">
+                        <i class="fa fa-plus-circle"></i>&nbsp;New Post
+                    </button>
+                </div>
             </div>
-        </div>
-        <!-- Modal -->
-        <div id="newPostModal" class="modal fade" role="dialog">
-          <div class="modal-dialog">
+            <!-- Modal -->
+            <div id="newPostModal" class="modal fade" role="dialog">
+              <div class="modal-dialog">
 
-            <!-- Modal content-->
-            <div class="modal-content">
-              <div class="modal-header">
-                <h4 class="modal-title">Create a new Post</h4>
-                <button type="button" class="close" data-dismiss="modal">&times;</button>
-              </div>
-              <div class="modal-body">
-                <form action="." method="POST" enctype='multipart/form-data'>
-                    <div class="form-group">
-                        {% csrf_token %}
-                        {{form}}
-                    </div>
-                    <input type="submit" class="btn btn-primary" value="Create Post">
-                </form>
-              </div>
-              <div class="modal-footer">
-                <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
+                <!-- Modal content-->
+                <div class="modal-content">
+                  <div class="modal-header">
+                    <h4 class="modal-title">Create a new Post</h4>
+                    <button type="button" class="close" data-dismiss="modal">&times;</button>
+                  </div>
+                  <div class="modal-body">
+                    <form action="." method="POST" enctype='multipart/form-data'>
+                        <div class="form-group">
+                            {% csrf_token %}
+                            {{form}}
+                        </div>
+                        <input type="submit" class="btn btn-primary" value="Create Post">
+                    </form>
+                  </div>
+                  <div class="modal-footer">
+                    <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
+                  </div>
+                </div>
               </div>
             </div>
-            
-          </div>
-        </div>
-        <br>
-        <div class="row justify-content-center">
-            <div class="col-md-6">
-                <form class="my-2 my-lg-0" action="" method="GET">
-                    <div class="input-group">
-                        <input type="search" placeholder="Search Post" name="search_post" class="form-control">
-                        <span class="input-group-append">
-                            <button class="btn btn-outline-info">
-                                <i class="fa fa-search"></i>&nbsp;Search
-                            </button>
-                        </span>
-                    </div>
-                </form>
-            </div>
-            <div class="col-md-4">
-                <a class="btn btn-outline-danger" href="{% url 'yaksh:course_forum' course.id %}">
-                    <i class="fa fa-times"></i>&nbsp;Clear Search
-                </a>
-            </div>
-        </div>
-        <br>
-        {% with objects as posts %}
-        {% if posts %}
-            {% include "yaksh/paginator.html" %}
             <br>
-            <table id="posts_table" class="tablesorter table">
-                <thead class="thread-inverse">
-                    <tr>
-                        <th width="700">Posts</th>
-                        <th>Created by</th>
-                        <th>Replies</th>
-                        <th>Last reply</th>
-                        <th></th>
-                    </tr>
-                </thead>
-                <tbody>
-                    {% for post in posts %}
-                        <tr>
-                            <td>
-                                <a href="{% url 'yaksh:post_comments' course.id post.uid %}">{{post.title}}</a>
-                                <small class="text-muted d-block">{{ post.description|truncatewords:30 }}</small>
-                                <small class="text-muted"><strong>Last updated: {{post.modified_at}}</strong></small>
-                            </td>
-                            <td>{{post.creator.username}}</td>
-                            <td>{{post.get_comments_count}}</td>
-                            <td>
-                                {% with post.get_last_comment as last_comment %}
-                                    {% if last_comment %}
-                                        {{last_comment.creator}}
-                                    {% else %}
-                                        None
-                                    {% endif %}
-                                {% endwith %}
-                            </td>
-                            <td>
-                                {% if user.profile.is_moderator %}
-                                    <small><a href="{% url 'yaksh:hide_post' course.id post.uid %}" class="pull-right btn btn-danger">Delete</i></a></small>
-                                {% endif %}
-                            </td>
-                        </tr>
-                    {% endfor %}
-                </tbody>
-            </table>
+            <div class="row justify-content-center">
+                <div class="col-md-6">
+                    <form class="my-2 my-lg-0" action="" method="GET">
+                        <div class="input-group">
+                            <input type="search" placeholder="Search Post" name="search_post" class="form-control">
+                            <span class="input-group-append">
+                                <button class="btn btn-outline-info">
+                                    <i class="fa fa-search"></i>&nbsp;Search
+                                </button>
+                            </span>
+                        </div>
+                    </form>
+                </div>
+                <div class="col-md-4">
+                    <a class="btn btn-outline-danger" href="{% url 'yaksh:course_forum' course.id %}">
+                        <i class="fa fa-times"></i>&nbsp;Clear Search
+                    </a>
+                </div>
+            </div>
             <br>
-            {% include "yaksh/paginator.html" %}
-        {% else %}
-            No discussion posts are there yet. Create one to start discussing.
-        {% endif %}
-        {% endwith %}
+            {% with objects as posts %}
+                {% if posts %}
+                    {% include "yaksh/paginator.html" %}
+                    <br>
+                    <table id="posts_table" class="tablesorter table">
+                        <thead class="thread-inverse">
+                            <tr>
+                                <th width="700">Posts</th>
+                                <th>Created by</th>
+                                <th>Replies</th>
+                                <th>Last reply</th>
+                                <th></th>
+                            </tr>
+                        </thead>
+                        <tbody>
+                            {% for post in posts %}
+                                <tr>
+                                    <td>
+                                        <a href="{% url 'yaksh:post_comments' course.id post.uid %}">{{post.title}}</a>
+                                        <small class="text-muted d-block">{{ post.description|truncatewords:30 }}</small>
+                                        <small class="text-muted"><strong>Last updated: {{post.modified_at}}</strong></small>
+                                    </td>
+                                    <td>{{post.creator.username}}</td>
+                                    <td>{{post.get_comments_count}}</td>
+                                    <td>
+                                        {% with post.get_last_comment as last_comment %}
+                                            {% if last_comment %}
+                                                {{last_comment.creator}}
+                                            {% else %}
+                                                None
+                                            {% endif %}
+                                        {% endwith %}
+                                    </td>
+                                    <td>
+                                        {% if user.profile.is_moderator %}
+                                            <small><a href="{% url 'yaksh:hide_post' course.id post.uid %}" class="pull-right fa fa-trash"></i></a></small>
+                                        {% endif %}
+                                    </td>
+                                </tr>
+                            {% endfor %}
+                        </tbody>
+                    </table>
+                    <br>
+                    {% include "yaksh/paginator.html" %}
+                {% else %}
+                    No discussion posts are there yet. Create one to start discussing.
+                {% endif %}
+            {% endwith %}
+        </div>
     </div>
 {% endblock content %}
 {% block script %}
diff --git a/yaksh/templates/yaksh/lessons_forum.html b/yaksh/templates/yaksh/lessons_forum.html
new file mode 100644
index 0000000..a4fd23b
--- /dev/null
+++ b/yaksh/templates/yaksh/lessons_forum.html
@@ -0,0 +1,70 @@
+{% extends base_template %}
+{% load static %}
+{% block title %}
+    {{course.name}}: Lessons Forum
+{% endblock title %}
+{% block content %}
+    <div id="wrapper" class="d-flex">
+        {% include "yaksh/sidebar.html" %}
+        <div class="container" id="page-content-wrapper">
+            <div>
+                <h2><center>{{course.name}}</center></h2>
+                <center>Discussion Forum</center>
+            </div>
+            <div class="d-flex p-2 bd-highlight">
+                <div class="col-md-4">
+                    {% if moderator %}
+                        <a href="{% url 'yaksh:course_detail' course.id %}" class="btn btn-primary">
+                            <i class="fa fa-arrow-left"></i>&nbsp;Back
+                        </a>
+                    {% else %}
+                        <a href="{% url 'yaksh:course_modules' course.id %}" class="btn btn-primary">
+                            <i class="fa fa-arrow-left"></i>&nbsp;Back
+                        </a>
+                    {% endif %}
+                </div>
+            </div>
+            {% if posts %}
+                <table class="table">
+                    <thead class="thread-inverse">
+                        <tr>
+                            <th width="700">Posts</th>
+                            <th>Created by</th>
+                            <th>Replies</th>
+                            <th>Last reply</th>
+                            <th></th>
+                        </tr>
+                    </thead>
+                    <tbody>
+                        {% for post in posts %}
+                                <tr>
+                                    <td>
+                                        <a href="{% url 'yaksh:post_comments' course.id post.uid %}">{{post.title}}</a>
+                                        <small class="text-muted d-block">{{ post.description|truncatewords:30 }}</small>
+                                        <small class="text-muted"><strong>Last updated: {{post.modified_at}}</strong></small>
+                                    </td>
+                                    <td>{{post.creator.username}}</td>
+                                    <td>{{post.get_comments_count}}</td>
+                                    <td>
+                                        {% with post.get_last_comment as last_comment %}
+                                            {% if last_comment %}
+                                                {{last_comment.creator}}
+                                            {% else %}
+                                                None
+                                            {% endif %}
+                                        {% endwith %}
+                                    </td>
+                                    <td>
+                                        {% if user.profile.is_moderator %}
+                                            <small><a href="{% url 'yaksh:hide_post' course.id post.uid %}" class="pull-right fa fa-trash"></i></a></small>
+                                        {% endif %}
+                                    </td>
+                                </tr>
+                            {% endfor %}
+                    </tbody>
+                </table>
+            {% endif %}
+        </div>
+    </div>
+{% endblock content %}
+
diff --git a/yaksh/templates/yaksh/post_comments.html b/yaksh/templates/yaksh/post_comments.html
index f0f1593..6051b6e 100644
--- a/yaksh/templates/yaksh/post_comments.html
+++ b/yaksh/templates/yaksh/post_comments.html
@@ -6,7 +6,7 @@
 
 {% block content %}
     <div class="container">
-        <a class="btn btn-primary" href="{% url 'yaksh:course_forum' post.target.id %}">
+        <a class="btn btn-primary" href="{% url 'yaksh:course_forum' course.id %}">
             <i class="fa fa-arrow-left"></i>&nbsp;Back to Posts
         </a>
         <br>
@@ -18,7 +18,7 @@
                 <small>
                     <strong>{{post.creator.username}}</strong>
                     {{post.created_at}}
-                    {% if user.profile.is_moderator %}<a href="{% url 'yaksh:hide_post' post.target.id post.uid %}" class="pull-right btn btn-danger">Delete</a>{% endif %}
+                    {% if user.profile.is_moderator %}<a href="{% url 'yaksh:hide_post' post.target.id post.uid %}" class="pull-right fa fa-trash"></a>{% endif %}
                 </small>
 
             </div>
@@ -41,7 +41,7 @@
                                 <strong class="text-muted">{{comment.creator.username}}</strong>
                             </div>
                             <div class="col-6 text-right">
-                                <small class="text-muted">{{comment.created_at}} {% if user.profile.is_moderator %} <a href="{% url 'yaksh:hide_comment' post.target.id comment.uid %}" class="btn btn-danger">Delete</a>{% endif %}</small>
+                                <small class="text-muted">{{comment.created_at}} {% if user.profile.is_moderator %} <a href="{% url 'yaksh:hide_comment' post.target.id comment.uid %}" class="fa fa-trash"></a>{% endif %}</small>
                             </div>
                         </div>
                         <p class="card-text description">{{comment.description}}</p>
diff --git a/yaksh/templates/yaksh/show_video.html b/yaksh/templates/yaksh/show_video.html
index 76a48d4..ef6f459 100644
--- a/yaksh/templates/yaksh/show_video.html
+++ b/yaksh/templates/yaksh/show_video.html
@@ -236,7 +236,7 @@
                                 <strong class="text-muted">{{comment.creator.username}}</strong>
                             </div>
                             <div class="col-6 text-right">
-                                <small class="text-muted">{{comment.created_at}} {% if user.profile.is_moderator %} <a href="{% url 'yaksh:hide_comment' course.id comment.uid %}" class="btn btn-danger">Delete</a>{% endif %}</small>
+                                <small class="text-muted">{{comment.created_at}} {% if user.profile.is_moderator %} <a href="{% url 'yaksh:hide_comment' course.id comment.uid %}" class="fa fa-trash"></a>{% endif %}</small>
                             </div>
                         </div>
                         <p class="card-text description">{{comment.description}}</p>
diff --git a/yaksh/templates/yaksh/sidebar.html b/yaksh/templates/yaksh/sidebar.html
new file mode 100644
index 0000000..7d0ac74
--- /dev/null
+++ b/yaksh/templates/yaksh/sidebar.html
@@ -0,0 +1,8 @@
+<!-- Sidebar -->
+<div class="bg-light border-right" id="sidebar-wrapper">
+  <div class="list-group list-group-flush">
+    <a href="{% url 'yaksh:course_forum' course.id %}" class="list-group-item list-group-item-action {% if '/course_forum/' in request.path %}active{% endif %}">Course Forum</a>
+    <a href="{% url 'yaksh:lessons_forum' course.id %}" class="list-group-item list-group-item-action {% if '/lessons_forum/' in request.path %}active{% endif %}">Lessons Forum</a>
+  </div>
+</div>
+<!-- /#sidebar-wrapper -->
diff --git a/yaksh/urls.py b/yaksh/urls.py
index b60b5f5..82785ca 100644
--- a/yaksh/urls.py
+++ b/yaksh/urls.py
@@ -60,9 +60,11 @@ urlpatterns = [
         views.get_next_unit, name='next_unit'),
     url(r'^course_modules/(?P<course_id>\d+)/$',
         views.course_modules, name='course_modules'),
-    url(r'^forum/(?P<course_id>\d+)/$',
+    url(r'^forum/course_forum/(?P<course_id>\d+)/$',
         views.course_forum,
         name='course_forum'),
+    url(r'^forum/lessons_forum/(?P<course_id>\d+)/$',
+        views.lessons_forum, name='lessons_forum'),
     url(r'^forum/(?P<course_id>\d+)/post/(?P<uuid>[0-9a-f-]+)/$',
         views.post_comments,
         name='post_comments'),
diff --git a/yaksh/views.py b/yaksh/views.py
index ae00fc6..084ec1e 100644
--- a/yaksh/views.py
+++ b/yaksh/views.py
@@ -2811,7 +2811,6 @@ def show_lesson(request, lesson_id, module_id, course_id):
         post = Post.objects.get(
             target_ct=lesson_ct, target_id=learn_unit.lesson.id,
             active=True, title=title, creator=user,
-            description=f'Discussion on {title} lesson',
         )
     except Post.DoesNotExist:
         post = Post.objects.create(
@@ -3519,6 +3518,27 @@ def course_forum(request, course_id):
 
 @login_required
 @email_verified
+def lessons_forum(request, course_id):
+    user = request.user
+    base_template = 'user.html'
+    moderator = False
+    if is_moderator(user):
+        base_template = 'manage.html'
+        moderator = True
+    course = get_object_or_404(Course, id=course_id)
+    course_ct = ContentType.objects.get_for_model(course)
+    lesson_posts = course.get_lesson_posts(user)
+    return render(request, 'yaksh/lessons_forum.html', {
+        'user': user,
+        'base_template': base_template,
+        'moderator': moderator,
+        'course': course,
+        'posts': lesson_posts,
+    })
+
+
+@login_required
+@email_verified
 def post_comments(request, course_id, uuid):
     user = request.user
     base_template = 'user.html'
@@ -3545,6 +3565,7 @@ def post_comments(request, course_id, uuid):
         'base_template': base_template,
         'form': form,
         'user': user,
+        'course': course
         })
 
 
@@ -3554,7 +3575,9 @@ def hide_post(request, course_id, uuid):
     user = request.user
     course = get_object_or_404(Course, id=course_id)
     if (not course.is_creator(user) or not course.is_teacher(user)):
-        raise Http404(f'Only a course creator or a teacher can delete the post.')
+        raise Http404(
+            'Only a course creator or a teacher can delete the post.'
+        )
     post = get_object_or_404(Post, uid=uuid)
     post.comment.active = False
     post.active = False
@@ -3570,7 +3593,7 @@ def hide_comment(request, course_id, uuid):
         course = get_object_or_404(Course, id=course_id)
         if (not course.is_creator(user) or not course.is_teacher(user)):
             raise Http404(
-                f'Only a course creator or a teacher can delete the comments'
+                'Only a course creator or a teacher can delete the comments'
             )
     comment = get_object_or_404(Comment, uid=uuid)
     post_uid = comment.post_field.uid