Adds extensible header functionality

This change is to introduce a flexible mechanism for projects to
add content to horizon's navbar.
- Introduces a new plugin file variable called ADD_HEADER_SECTIONS,
  which will take a list of views.  These are template views that
  will be used to render individual header sections.
- There is a new view in openstack_dashboard/views.py to cycle
  through these added views and combine them into the complete
  header to be added to the navbar.
- This view is queried by newly added javascript after page load.
  On response it is inserted into the page's navbar.
  If more than one header is present, the first will be shown in
  the navbar, while the rest are added to a drop-down menu.
- The currently displayed header can be changed by clicking on a
  new header in the drop-down; this is stored in a cookie to
  persist the selection between pages.
- Unit tests were modified/added to verify the new plugin entry
  can be parsed successfully and the main header view can parse
  a plugin's view successfully

Change-Id: I177b69ec4e78c17f827e540a7e669af1c29e8b59
Implements: blueprint extensible-header
Signed-off-by: Tyler Smith <tyler.smith@windriver.com>

doc/source/contributor/tutorials/plugin.rst

@@ -149,6 +149,9 @@ _31000_myplugin.py::
     # A list of scss files to be included in the compressed set of files
     ADD_SCSS_FILES = ['dashboard/identity/myplugin/mypanel/mypanel.scss']
 
+    # A list of template-based views to be added to the header
+    ADD_HEADER_SECTIONS = ['myplugin.content.mypanel.views.HeaderView',]
+
 ..  Note ::
 
   Currently, AUTO_DISCOVER_STATIC_FILES = True will only discover JavaScript files,

horizon/static/horizon/js/horizon.extensible_header.js

@@ -0,0 +1,65 @@
+/**
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License. You may obtain
+ * a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ */
+
+/* Core functionality related to extensible header sections. */
+horizon.extensible_header = {
+  populate: function() {
+    var $path = $(location).attr('pathname');
+    var $url = $(location).attr('href');
+    $url = $url.replace($path, $(window).attr('WEBROOT') + 'header/');
+
+    horizon.ajax.queue({
+      url: $url,
+      success: function(data) {
+        $('#extensible-header').replaceWith($(data));
+
+        selected = horizon.cookies.get('selected_header');
+        if(selected && $('#header-list #' + selected).length){
+          $old_primary = $('#primary-extensible-header > a');
+          $new_primary = $('#header-list #' + selected);
+
+          $old_primary.insertAfter($new_primary);
+          $new_primary.first().appendTo($('#primary-extensible-header'));
+        }
+
+        function swap() {
+          $old_primary = $('#primary-extensible-header > a');
+          $new_primary = $(this);
+
+          horizon.cookies.put("selected_header", $new_primary.attr('id'), {path:'/'});
+          $old_primary.insertAfter($new_primary);
+          $new_primary.appendTo($('#primary-extensible-header'));
+          $new_primary.off('click', swap);
+          $old_primary.on('click', swap);
+        }
+        $('#header-list .extensible-header-section').on('click', swap);
+      },
+      error: function(jqXHR) {
+        if (jqXHR.status !== 401 && jqXHR.status !== 403) {
+          // error is raised with status of 0 when ajax query is cancelled
+          // due to new page request
+          if (jqXHR.status !== 0) {
+            horizon.alert("info", gettext("Failed to populate extensible header."));
+          }
+        }
+      }
+    });
+    return true;
+  }
+};
+
+horizon.addInitFunction(function() {
+  // trigger extensible header section query on page load
+  horizon.extensible_header.populate();
+});

openstack_dashboard/static/dashboard/scss/components/_navbar.scss

@@ -23,6 +23,11 @@
     margin-bottom: 1px;
   }
 
+  .navbar-nav .header-overflow ul li{
+    white-space: nowrap;
+    padding: $bs-dropdown-item-padding-vertical $bs-dropdown-item-padding-horizontal;
+  }
+
   .dropdown-toggle > .fa {
     padding-left: $padding-small-vertical;
     padding-right: $padding-small-vertical;

openstack_dashboard/templates/header/_header.html

@@ -29,6 +29,7 @@
       </ul>
 
       <ul class="nav navbar-nav navbar-right">
+        <li id="extensible-header" class="extensible-header"></li>
         {% if profiler_enabled %}
           {% include "developer/profiler/_mode_picker.html" %}
         {% endif %}

openstack_dashboard/templates/header/_header_sections.html

@@ -0,0 +1,28 @@
+{% load i18n %}
+
+<li id="primary-extensible-header" class="dropdown extensible-header">
+  {% for header in header_sections%}
+    {% if forloop.first %}
+      <a id="{{ header.0 }}" class="extensible-header-section"> {% autoescape off %}{{ header.1 }}{% endautoescape %} </a>
+    {% endif %}
+  {% endfor %}
+</li>
+
+{% if header_sections|length > 1 %}
+<li class="dropdown header-overflow">
+  <a data-toggle="dropdown" href="#" class="dropdown-toggle" role="button" aria-expanded="false">
+    <span>{% trans "More" %}</span>
+    <span class="fa fa-caret-down"></span>
+  </a>
+
+  <ul id="header-list" class="dropdown-menu dropdown-menu-right selection-menu">
+    {% for header in header_sections%}
+      {% if not forloop.first %}
+          <li>
+            <a id="{{ header.0 }}" class="extensible-header-section"> {% autoescape off %}{{ header.1 }}{% endautoescape %} </a>
+          </li>
+      {% endif %}
+    {% endfor %}
+  </ul>
+</li>
+{% endif %}

openstack_dashboard/templates/horizon/_scripts.html

@@ -44,6 +44,7 @@
 <script src='{{ STATIC_URL }}horizon/js/horizon.d3linechart.js'></script>
 <script src='{{ STATIC_URL }}horizon/js/horizon.d3barchart.js'></script>
 <script src='{{ STATIC_URL }}horizon/js/horizon.sidebar.js'></script>
+<script src='{{ STATIC_URL }}horizon/js/horizon.extensible_header.js'></script>
 <script src='{{ STATIC_URL }}js/horizon.instances.js'></script>
 <script src='{{ STATIC_URL }}js/horizon.quota.js'></script>
 <script src='{{ STATIC_URL }}js/horizon.metering.js'></script>

openstack_dashboard/test/extensible_header_urls.py

@@ -0,0 +1,18 @@
+#  Licensed under the Apache License, Version 2.0 (the "License"); you may
+#  not use this file except in compliance with the License. You may obtain
+#  a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#  License for the specific language governing permissions and limitations
+#  under the License.
+
+from django.conf.urls import url
+
+from openstack_dashboard.urls import urlpatterns  # noqa
+from openstack_dashboard import views
+
+urlpatterns.append(url(r'^header/', views.ExtensibleHeaderView.as_view()))

openstack_dashboard/test/test_panels/plugin_panel/templates/plugin_panel/header.html

@@ -0,0 +1,6 @@
+{% load i18n %}
+
+<span class="test-header">
+  <strong>{% trans "This is a test: " %}  </strong>
+  <span class="badge">{{ message }}</span>
+</span>

openstack_dashboard/test/test_panels/plugin_panel/views.py

@@ -16,3 +16,13 @@ from horizon import views
 class IndexView(views.HorizonTemplateView):
     template_name = 'admin/plugin_panel/index.html'
     page_title = 'Plugin-based Panel'
+
+
+class TestBannerView(views.HorizonTemplateView):
+    template_name = 'admin/plugin_panel/header.html'
+
+    def get_context_data(self, **kwargs):
+        context = super(TestBannerView, self).get_context_data(**kwargs)
+
+        context['message'] = "sample context"
+        return context

openstack_dashboard/test/test_plugins/panel_config/_10_admin_add_panel.py

@@ -22,4 +22,8 @@ ADD_JS_FILES = ['plugin_panel/plugin_module.js']
 ADD_JS_SPEC_FILES = ['plugin_panel/plugin.spec.js']
 
 # A list of scss files to be included in the compressed set of files
-ADD_SCSS_FILES = ['plugin_panel/plugin.scss']
+ADD_SCSS_FILES = ['plugin_panel/plugin.scss']
+
+# A list of extensible header views to be displayed
+ADD_HEADER_SECTIONS = \
+    ['openstack_dashboard.test.test_panels.plugin_panel.views.TestBannerView',]

openstack_dashboard/test/test_plugins/panel_tests.py

@@ -44,6 +44,8 @@ util_settings.update_dashboards([panel_config,], HORIZON_CONFIG, INSTALLED_APPS)
 @override_settings(HORIZON_CONFIG=HORIZON_CONFIG,
                    INSTALLED_APPS=INSTALLED_APPS)
 class PanelPluginTests(test.PluginTestCase):
+    urls = 'openstack_dashboard.test.extensible_header_urls'
+
     def test_add_panel(self):
         dashboard = horizon.get_dashboard("admin")
         panel_group = dashboard.get_panel_group('admin')
@@ -58,6 +60,12 @@ class PanelPluginTests(test.PluginTestCase):
         self.assertEqual(pc.ADD_JS_FILES, HORIZON_CONFIG['js_files'])
         self.assertEqual(pc.ADD_JS_SPEC_FILES, HORIZON_CONFIG['js_spec_files'])
         self.assertEqual(pc.ADD_SCSS_FILES, HORIZON_CONFIG['scss_files'])
+        self.assertEqual(pc.ADD_HEADER_SECTIONS,
+                         HORIZON_CONFIG['header_sections'])
+
+    def test_extensible_header(self):
+        response = self.client.get('/header/')
+        self.assertIn('sample context', response.content)
 
     def test_remove_panel(self):
         dashboard = horizon.get_dashboard("admin")

openstack_dashboard/themes/material/templates/header/_header.html

@@ -29,6 +29,7 @@
       </ul>
 
       <ul class="nav navbar-nav navbar-right">
+        <li id="extensible-header" class="extensible-header"></li>
         {% if profiler_enabled %}
           {% include "developer/profiler/_mode_picker.html" %}
         {% endif %}

openstack_dashboard/urls.py

@@ -35,6 +35,7 @@ from openstack_dashboard import views
 urlpatterns = [
     url(r'^$', views.splash, name='splash'),
     url(r'^api/', include(rest.urls)),
+    url(r'^header/', views.ExtensibleHeaderView.as_view()),
     url(r'', include(horizon.urls)),
 ]
 

openstack_dashboard/utils/settings.py

@@ -110,6 +110,7 @@ def update_dashboards(modules, horizon_config, installed_apps):
     js_spec_files = []
     scss_files = []
     panel_customization = []
+    header_sections = []
     update_horizon_config = {}
     for key, config in import_dashboard_config(modules):
         if config.get('DISABLED', False):
@@ -120,6 +121,9 @@ def update_dashboards(modules, horizon_config, installed_apps):
         _apps = config.get('ADD_INSTALLED_APPS', [])
         apps.extend(_apps)
 
+        _header_sections = config.get('ADD_HEADER_SECTIONS', [])
+        header_sections.extend(_header_sections)
+
         if config.get('AUTO_DISCOVER_STATIC_FILES', False):
             for _app in _apps:
                 module = import_module(_app)
@@ -156,6 +160,7 @@ def update_dashboards(modules, horizon_config, installed_apps):
                    if d not in config_dashboards])
 
     horizon_config['panel_customization'] = panel_customization
+    horizon_config['header_sections'] = header_sections
     horizon_config['dashboards'] = tuple(dashboards)
     horizon_config.setdefault('exceptions', {}).update(exceptions)
     horizon_config.update(update_horizon_config)

openstack_dashboard/views.py

@@ -12,10 +12,14 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from importlib import import_module
+import logging
+
 from django.conf import settings
 from django.core import urlresolvers
 from django import shortcuts
 import django.views.decorators.vary
+from django.views.generic import TemplateView
 from six.moves import urllib
 
 import horizon
@@ -23,6 +27,8 @@ from horizon import base
 from horizon import exceptions
 from horizon import notifications
 
+LOG = logging.getLogger(__name__)
+
 
 MESSAGES_PATH = getattr(settings, 'MESSAGES_PATH', None)
 
@@ -80,3 +86,35 @@ def get_url_with_pagination(request, marker_name, prev_marker_name, url_string,
                               urllib.parse.urlencode({prev_marker_name:
                                                       prev_marker}))
     return url
+
+
+class ExtensibleHeaderView(TemplateView):
+    template_name = 'header/_header_sections.html'
+
+    def get_context_data(self, **kwargs):
+        context = super(ExtensibleHeaderView, self).get_context_data(**kwargs)
+        header_sections = []
+        config = getattr(settings, 'HORIZON_CONFIG', {})
+        for view_path in config.get("header_sections", []):
+            mod_path, view_cls = view_path.rsplit(".", 1)
+            try:
+                mod = import_module(mod_path)
+            except ImportError:
+                LOG.warning("Could not load header view: %s", mod_path)
+                continue
+
+            try:
+                view = getattr(mod, view_cls)(request=self.request)
+                response = view.get(self.request)
+                rendered_response = response.render()
+                packed_response = [view_path.replace('.', '-'),
+                                   rendered_response.content]
+                header_sections.append(packed_response)
+
+            except Exception as e:
+                LOG.warning("Could not render header %(path)s, exception: "
+                            "%(exc)s", {'path': view_path, 'exc': e})
+                continue
+
+        context['header_sections'] = header_sections
+        return context

releasenotes/notes/extensible-header-ac3c94f3057c1b2a.yaml

@@ -0,0 +1,5 @@
+---
+features:
+  - >
+    [`blueprint extensible-header <https://blueprints.launchpad.net/horizon/+spec/extensible-header>`_]
+    Added a feature to insert custom headers into horizon's topbar.