CLDC-1618 Add cookie banner

app/views/cookies/_banner.html.erb

@@ -0,0 +1,48 @@
+<div class="govuk-cookie-banner js-cookie-banner" role="region" aria-label="Cookies on CORE">
+  <div class="govuk-cookie-banner__message govuk-width-container js-cookie-banner__form">
+    <div class="govuk-grid-row">
+      <div class="govuk-grid-column-two-thirds">
+        <h2 class="govuk-cookie-banner__heading govuk-heading-m">Cookies on CORE</h2>
+
+        <div class="govuk-cookie-banner__content">
+          <p class="govuk-body">We use some essential cookies to make this service work.</p>
+          <p class="govuk-body">We’d like to use analytics cookies so we can understand how you use the service and make improvements.</p>
+        </div>
+      </div>
+    </div>
+
+    <%= form_with url: cookies_path, class: "js-cookie-form", method: :put do |f| %>
+      <div class="govuk-button-group">
+        <button type="submit" class="govuk-button" name="cookies_form[analytics_consent]" value="on">
+          Accept analytics cookies
+        </button>
+        <button type="submit" class="govuk-button" name="cookies_form[analytics_consent]" value="off">
+          Reject analytics cookies
+        </button>
+        <%= govuk_link_to "View cookies", cookies_path %>
+      </div>
+    <% end %>
+  </div>
+
+  <div class="govuk-cookie-banner__message govuk-width-container js-cookie-banner__success" role="alert" hidden>
+    <div class="govuk-grid-row">
+      <div class="govuk-grid-column-two-thirds">
+
+        <div class="govuk-cookie-banner__content">
+          <p class="govuk-body">
+            <span class="js-cookie-message">
+              You’ve set your cookie preferences.
+            </span>
+            You can <%= govuk_link_to "change your cookie settings", cookies_path %> at any time.
+          </p>
+        </div>
+      </div>
+    </div>
+
+    <div class="govuk-button-group">
+      <button class="govuk-button js-hide-cookie-banner">
+        Hide this message
+      </button>
+    </div>
+  </div>
+</div>

app/views/layouts/application.html.erb

@@ -25,6 +25,7 @@
     <% gtm_container = get_gtm_container %>
     <% gtm_id = get_gtm_id %>
 
+    <% if cookies[:accept_analytics_cookies] == "on" %>
       <!-- Google Tag Manager (doesn't store personal info until permission given) -->
       <script>(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':
       new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],
@@ -33,7 +34,6 @@
       })(window,document,'script','dataLayer','<%= gtm_container %>');</script>
       <!-- End Google Tag Manager -->
 
-    <% if cookies[:accept_analytics_cookies] == "on" %>
       <script async src="https://www.googletagmanager.com/gtag/js?id=<%= gtm_id %>"></script>
     <% else %>
       <script>
@@ -72,13 +72,17 @@
       document.body.className = ((document.body.className) ? document.body.className + " js-enabled" : "js-enabled");
     </script>
 
+    <% if cookies[:accept_analytics_cookies] == "on" %>
       <!-- Google Tag Manager (noscript) -->
-    <% if cookies[:accept_analytics_cookies] %>
       <noscript>
         <iframe src="https://www.googletagmanager.com/ns.html?id=<% gtm_container %>" height="0" width="0" style="display:none;visibility:hidden"></iframe>
       </noscript>
     <% end %>
 
+    <% unless cookies[:accept_analytics_cookies] || current_page?(cookies_path) %>
+      <%= render "cookies/banner" %>
+    <% end %>
+
     <%= govuk_skip_link %>
 
     <%= govuk_header(