Add translation support

Change-Id: I8cc38cd00683ce6f0ef8f62eb9eeddfc84c52a34

package.json

@@ -18,6 +18,7 @@
   },
   "dependencies": {
     "prop-types": "^15.7.2",
+    "ra-language-german": "^2.1.2",
     "react": "^16.12.0",
     "react-admin": "^3.1.3",
     "react-dom": "^16.12.0",

src/App.js

@@ -1,9 +1,22 @@
 import React from "react";
-import { Admin, Resource } from "react-admin";
+import { Admin, Resource, resolveBrowserLocale } from "react-admin";
+import polyglotI18nProvider from "ra-i18n-polyglot";
 import dataProvider from "./dataProvider";
+import germanMessages from "./i18n/de";
+import englishMessages from "./i18n/en";
+
+// TODO: Can we use lazy loading together with browser locale?
+const messages = {
+  de: germanMessages,
+  en: englishMessages,
+};
+const i18nProvider = polyglotI18nProvider(
+  locale => (messages[locale] ? messages[locale] : messages.en),
+  resolveBrowserLocale()
+);
 
 const App = () => (
-  <Admin dataProvider={dataProvider}>
+  <Admin dataProvider={dataProvider} i18nProvider={i18nProvider}>
     <Resource name="data" />
   </Admin>
 );

src/i18n/de.js

@@ -0,0 +1,5 @@
+import germanMessages from "ra-language-german";
+
+export default {
+  ...germanMessages,
+};

src/i18n/en.js

@@ -0,0 +1,5 @@
+import englishMessages from "ra-language-english";
+
+export default {
+  ...englishMessages,
+};

yarn.lock

@@ -8974,6 +8974,11 @@ ra-language-english@^3.2.0:
   resolved "https://registry.yarnpkg.com/ra-language-english/-/ra-language-english-3.2.0.tgz#2ca13b767d834b43fefd128f48e452449f812b61"
   integrity sha512-/XmwYWoQoB4MBkkzBCbg/ykCuRGjHQOHLk2ik6n1aM10AWHxiiJNyRw2aoLzH7Vc5rcp4BBJQCuhT+DgfYIJ2Q==
 
+ra-language-german@^2.1.2:
+  version "2.1.2"
+  resolved "https://registry.yarnpkg.com/ra-language-german/-/ra-language-german-2.1.2.tgz#d183093d470ab499ece91838cb67222db88f2e4f"
+  integrity sha512-N+BaBP0z98ujaKVlAMIKTfWHgmTiWD8sPQrU5vA3+b5zY9U0mMB4VjvU8sQQPR7rZE0gsRgS/X4V6ycDtNL6iQ==
+
 ra-ui-materialui@^3.2.1:
   version "3.2.1"
   resolved "https://registry.yarnpkg.com/ra-ui-materialui/-/ra-ui-materialui-3.2.1.tgz#8e0d9b74c36e9f800b8b766d67dfc720b821f561"