FEATURE: internet explorer deprecation global notice (#8577)

plugins/discourse-internet-explorer/assets/javascripts/initializers/discourse-internet-explorer.js.es6

@@ -0,0 +1,23 @@
+import { withPluginApi } from "discourse/lib/plugin-api";
+
+function initializeInternetExplorerDeprecation(api) {
+  const siteSettings = api.container.lookup("site-settings:main");
+  if (siteSettings.discourse_internet_explorer_deprecation_warning) {
+    const { isIE11 } = api.container.lookup("capabilities:main");
+    if (isIE11) {
+      api.addGlobalNotice(
+        I18n.t("discourse_internet_explorer.deprecation_warning"),
+        "deprecate-internet-explorer",
+        { dismissable: true }
+      );
+    }
+  }
+}
+
+export default {
+  name: "discourse-internet-explorer",
+
+  initialize() {
+    withPluginApi("0.8.37", initializeInternetExplorerDeprecation);
+  }
+};

plugins/discourse-internet-explorer/config/locales/client.en.yml

@@ -0,0 +1,4 @@
+en:
+  js:
+    discourse_internet_explorer:
+      deprecation_warning: Internet Explorer support is ending in early 2020.

plugins/discourse-internet-explorer/config/locales/server.en.yml

@@ -1,3 +1,4 @@
 en:
   site_settings:
     discourse_internet_explorer_enabled: "Internet Explorer support"
+    discourse_internet_explorer_deprecation_warning: "Show an Internet Explorer deprecation warning"

plugins/discourse-internet-explorer/config/settings.yml

@@ -1,3 +1,6 @@
 plugins:
   discourse_internet_explorer_enabled:
     default: true
+  discourse_internet_explorer_deprecation_warning:
+    default: false
+    client: true