Pass the current locale from Rails

To ensure that we have consistent locales being applied in both Rails
and Vue, we pass the current locale from Rails via the `window.ukhpi`
state object. This is more reliable than checking URL arguments, since
we also detect if the user is selecting a language using the HTTP
`Accept-Language` header.

app/javascript/lang/index.js

@@ -6,7 +6,11 @@ Vue.use(VueI18n)
 const localeEn = require('../../../config/locales/en.yml')
 const localeCy = require('../../../config/locales/cy.yml')
 
+// The locale is passed via the window.ukhpi structure
+// directly from Rails
+const currentLocale = window.ukhpi.locale || 'en'
+
 export default new VueI18n({
-  locale: 'en',
+  locale: currentLocale,
   messages: { ...localeEn, ...localeCy }
 })

app/views/layouts/webpack_application.html.haml

@@ -11,6 +11,7 @@
       window.ukhpi = window.ukhpi || {};
       window.ukhpi.environment = '#{ENV["DEPLOYMENT_ENVIRONMENT"] || Rails.env}';
       window.ukhpi.version = '#{Version::VERSION}';
+      window.ukhpi.locale = '#{I18n.locale}';
 
     = stylesheet_link_tag 'application', media: 'all'
     = csrf_meta_tags

config/locales/cy.yml

@@ -132,6 +132,12 @@ cy:
   js:
     action:
       download: "# Download this data"
+      data_graph: "# See data graph"
+      data_table: "# See data table"
+      compare: "# Compare with location ..."
+
+    graph:
+      no_data: "# Sorry, there is no %{label} data available for %{location}. Please select a different location."
 
 # old-------------