kb: add tag cloud in default view

welco/kb/templates/kb/zone.html

@@ -4,6 +4,14 @@
     <input type="text" autocomplete="off" placeholder="{% trans 'Keywords...' %}"  data-autocomplete-json="{% url 'kb-page-search-json' %}" name="q"/>
     <ul class="result">
     </ul>
+
+  {% if tags %}
+  <div class="tagcloud">
+    {% for tag in tags %}
+    <span style="font-size: {{tag.font_size}}">{{tag.name}}</span>
+    {% endfor %}
+  </div>
+  {% endif %}
   </div>
   <div class="page">
   </div>

welco/kb/views.py

@@ -21,6 +21,7 @@ from django.conf import settings
 from django.contrib.auth.decorators import login_required
 from django.core.exceptions import PermissionDenied
 from django.core.urlresolvers import reverse_lazy
+from django.db.models import Count
 from django.http import HttpResponse, HttpResponseRedirect
 from django.template import RequestContext
 from django.views.decorators.csrf import csrf_exempt
@@ -32,6 +33,7 @@ from haystack.generic_views import SearchView
 from haystack.query import SearchQuerySet
 from reversion.models import Version
 from reversion.revisions import default_revision_manager
+from taggit.models import Tag
 
 from .models import Page
 from .forms import PageForm
@@ -164,6 +166,25 @@ class KbZone(TemplateView):
     def get_context_data(self, **kwargs):
         context = super(KbZone, self).get_context_data(**kwargs)
         context['form'] = SearchForm()
+        context['tags'] = Tag.objects.all().annotate(
+                num_times=Count('taggit_taggeditem_items')).filter(num_times__gt=0)
+        num_times = context['tags'].values_list('num_times', flat=True)
+        delta = max(num_times) - min(num_times)
+        for tag in context['tags']:
+            if delta == 0:
+                tag.font_size = 'normal'
+            else:
+                factor = 1.0 * (tag.num_times - min(num_times)) / delta
+                if factor < 0.2:
+                    tag.font_size = 'x-small'
+                elif factor < 0.4:
+                    tag.font_size = 'small'
+                elif factor < 0.6:
+                    tag.font_size = 'normal'
+                elif factor < 0.8:
+                    tag.font_size = 'large'
+                else:
+                    tag.font_size = 'x-large'
         return context
 
 zone = csrf_exempt(KbZone.as_view())

welco/static/css/style.css

@@ -562,3 +562,7 @@ div.old-version.warning-notice form {
 	right: 1ex;
 	top: 1ex;
 }
+
+div.tagcloud {
+	padding: 1ex;
+}

welco/static/js/welco.js

@@ -246,6 +246,9 @@ $(function() {
     );
     return false;
   });
+  $('.kb').delegate('.tagcloud span', 'click', function() {
+    $('.kb input').val($(this).text()).trigger('keyup');
+  });
   $('.kb').delegate('ul.result a', 'click', function() {
     var page_slug = $(this).data('page-slug');
     var fragment_url = $(this).parents('[data-page-fragment-url]').data('page-fragment-url') + page_slug + '/';