Only show template navigation when it’s useful

There are lots of services that only send emails, or only send text
messages. For these services, being able to filter the list of templates
but type is pointless – it won’t cut the list down at all.

This commit adds some logic to only show the navigation if the service
has some variety of template types.

app/main/views/templates.py

@@ -88,6 +88,10 @@ def view_template(service_id, template_id):
 def choose_template(service_id, template_type='all'):
     templates = service_api_client.get_service_templates(service_id)['data']
 
+    has_multiple_template_types = len({
+        template['template_type'] for template in templates
+    }) > 1
+
     template_nav_items = [
         (label, key, url_for('.choose_template', service_id=current_service['id'], template_type=key), '')
         for label, key in filter(None, [
@@ -104,6 +108,7 @@ def choose_template(service_id, template_type='all'):
             template for template in templates
             if template_type in ['all', template['template_type']]
         ],
+        show_template_nav=has_multiple_template_types,
         template_nav_items=template_nav_items,
         template_type=template_type,
         search_form=SearchTemplatesForm(),

app/templates/views/templates/choose.html

@@ -48,9 +48,11 @@
       {% endif %}
     </div>
 
-    <div class="bottom-gutter-2-3">
-      {{ pill(template_nav_items, current_value=template_type, show_count=False) }}
-    </div>
+    {% if show_template_nav %}
+      <div class="bottom-gutter-2-3">
+        {{ pill(template_nav_items, current_value=template_type, show_count=False) }}
+      </div>
+    {% endif %}
 
     {% if templates|length > 7 %}
       <div data-module="autofocus">