From c2d01e9489f6ac41443cc2244e86e831a682f29a Mon Sep 17 00:00:00 2001
From: Felix Hamann <felix.hamann@campus.lmu.de>
Date: Sat, 6 Apr 2019 14:45:01 +0200
Subject: [PATCH] add i18n registry for JS utils

---
 src/Foundation.hs               |  1 +
 static/js/services/i18n.js      | 31 +++++++++++++++++++++++++++++++
 templates/default-layout.julius | 17 ++++++++++-------
 3 files changed, 42 insertions(+), 7 deletions(-)
 create mode 100644 static/js/services/i18n.js

diff --git a/src/Foundation.hs b/src/Foundation.hs
index fe0df0b26..cc5e85bcf 100644
--- a/src/Foundation.hs
+++ b/src/Foundation.hs
@@ -1067,6 +1067,7 @@ siteLayout' headingOverride widget = do
       -- JavaScript services
       addScript $ StaticR js_services_utilRegistry_js
       addScript $ StaticR js_services_httpClient_js
+      addScript $ StaticR js_services_i18n_js
       -- addScript $ StaticR js_utils_alerts_js
       -- addScript $ StaticR js_utils_asidenav_js
       -- addScript $ StaticR js_utils_asyncForm_js
diff --git a/static/js/services/i18n.js b/static/js/services/i18n.js
new file mode 100644
index 000000000..440b1aca5
--- /dev/null
+++ b/static/js/services/i18n.js
@@ -0,0 +1,31 @@
+(function() {
+  'use strict';
+
+  // Global I18n registry that stores and serves translations.
+  // Each translation must have a unique ID.
+  window.I18n = (function() {
+
+    var translations = {};
+
+    function addTranslation(id, translation) {
+      translations[id] = translation;
+    }
+
+    function addManyTranslations(manyTranslations) {
+      Object.keys(manyTranslations).forEach(function(key) {
+        addTranslation(key, manyTranslations[key]);
+      });
+    }
+
+    function getTranslation(id) {
+      return translations[id];
+    }
+
+    // public API
+    return {
+      add: addTranslation,
+      addMany: addManyTranslations,
+      get: getTranslation,
+    };
+  })();
+})();
diff --git a/templates/default-layout.julius b/templates/default-layout.julius
index d83daccd0..78e911914 100644
--- a/templates/default-layout.julius
+++ b/templates/default-layout.julius
@@ -35,13 +35,16 @@ function setupDatepicker(wrapper) {
   });
 }
 
-// this global I18N object will be picked up automatically by the setup util
-window.I18N = {
-  filesSelected: 'Dateien ausgewählt', // TODO: interpolate these to be translated
-  selectFile: 'Datei auswählen',
-  selectFiles: 'Datei(en) auswählen',
-  asyncFormFailure: 'Da ist etwas schief gelaufen, das tut uns Leid.<br>Falls das erneut passiert schicke uns gerne eine kurze Beschreibung dieses Ereignisses über das Hilfe-Widget rechts oben.<br><br>Vielen Dank für deine Hilfe',
-};
+if (I18n) {
+  I18n.addMany({
+    filesSelected: 'Dateien ausgewählt',
+    selectFile: 'Datei auswählen',
+    selectFiles: 'Datei(en) auswählen',
+    asyncFormFailure: 'Da ist etwas schief gelaufen, das tut uns Leid.<br>Falls das erneut passiert schicke uns gerne eine kurze Beschreibung dieses Ereignisses über das Hilfe-Widget rechts oben.<br><br>Vielen Dank für deine Hilfe',
+  });
+} else {
+  throw new Error('I18n JavaScript service is missing!');
+}
 
 document.addEventListener('DOMContentLoaded', function() {
   window.utils.setup('flatpickr', document.body, { setupFunction: setupDatepicker });