Added a warning when users are reading latest docs. closes #1789 (#1800)

doc/conf.py

@@ -14,6 +14,7 @@ html_static_path = ['static']
 def setup(app):
     app.add_object_type('generic', 'gen', 'pair: %s; generic')
     app.add_object_type('label', 'lab', 'pair: %s; label')
+    app.add_js_file("latest-warning.js")
 
 extensions = [
     'sphinx.ext.autodoc',

doc/static/latest-warning.js

+"use strict";
+
+// Source:
+// https://github.com/anymail/django-anymail/blob/4c443f5515d1d5269a95cb54cf75057c56a3b150/docs/_static/version-alert.js
+
+function warnOnLatestVersion() {
+
+  // The warning text and link is really specific to RTD hosting,
+  // so we can just check their global to determine version:
+  if (!window.READTHEDOCS_DATA || window.READTHEDOCS_DATA.version !== "latest") {
+    return;  // not latest, or not on RTD
+  }
+
+  var warning = document.createElement('div');
+  warning.setAttribute('class', 'admonition danger');
+  warning.innerHTML = "<p class='first admonition-title'>Note</p> " +
+    "<p class='last'> " +
+    "This document is for an <strong>unreleased development version</strong>. " +
+    "Documentation is available for the <a href='/en/stable/'>current stable release</a>, " +
+    "or for older versions through the &ldquo;v:&rdquo; menu at bottom left." +
+    "</p>";
+  warning.querySelector('a').href = window.location.pathname.replace('/latest', '/stable');
+
+  var parent = document.querySelector('div.body')
+    || document.querySelector('div.document')
+    || document.body;
+  parent.insertBefore(warning, parent.firstChild);
+}
+
+document.addEventListener('DOMContentLoaded', warnOnLatestVersion);