warning banner when using latest version (#1454)

fixes PIE-1474 add warning banner when using latest version

Signed-off-by: Adrian Sutton <adrian.sutton@consensys.net>

docs/custom_theme/assets/javascripts/pantheon_custom.js

@@ -0,0 +1,11 @@
+$( document ).ready(function() {
+  displayLatestWarning();
+});
+
+$(window).on('hashchange', function(){
+  displayLatestWarning();
+});
+
+function displayLatestWarning(){
+  $( ".latest-warning" ).css( "display", $(location).attr('href').includes(latestWarningTrigger)?"inherit":"none" );
+}

docs/custom_theme/assets/stylesheets/pantheon_custom.css

@@ -29,3 +29,13 @@
   font-weight: 900;
   font-size: small;
 }
+
+.latest-warning {
+  display: none;
+  padding: 1em;
+  background-color: orange;
+  color: black;
+  font-size: 1.5em;
+  text-align: center;
+  width: inherit;
+}

docs/custom_theme/main.html

@@ -8,7 +8,7 @@
       integrity="sha256-ZosEbRLbNQzLpnKIkEdrPv7lOy9C27hHQ+Xp8a4MxAQ="
       crossorigin="anonymous"></script>
   <script async src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.0/MathJax.js?config=TeX-MML-AM_CHTML"></script>
-
+  <script src="{{ 'assets/javascripts/pantheon_custom.js' | url }}"></script>
   {% if config.extra.google.site_verification %}
     <!-- Google site verification for search console -->
     <meta name="google-site-verification" content="{{config.extra.google.site_verification}}" />
@@ -28,3 +28,9 @@
 {% block analytics %}
   <!--Empty the footer analytics bloc as we need it the headers -->
 {% endblock %}
+
+{% block hero %}
+  {# hero is not used, so use it for warning banner #}
+  <script>const latestWarningTrigger = "{{config.extra.latest_version_warning.url_contains}}";</script>
+  <div class="latest-warning">{{config.extra.latest_version_warning.text}}</div>
+{% endblock %}

mkdocs.yml

@@ -22,6 +22,11 @@ extra:
   versions:
     pantheon_stable: &pantheon_stable_version 1.1.0
     quickstart: *pantheon_stable_version
+  latest_version_warning:
+    url_contains: /latest/
+    text: 'You are reading Pantheon development version documentation and
+    some displayed features may not be available in the stable release.
+    You can switch to stable version using the version box at screen bottom.'
   support:
     gitter: https://gitter.im/PegaSysEng/pantheon
     email: support@pegasys.tech