FEATURE: refactor notice code, add optional global notice.

Set the global_notice site setting to notify users of a critical event.

app/assets/javascripts/admin/templates/admin.js.handlebars

@@ -1,9 +1,5 @@
 <div class="container">
-  {{#if Discourse.isReadOnly}}
-    <div class="row">
-      <div class="alert alert-info">{{i18n "read_only_mode.enabled"}}</div>
-    </div>
-  {{/if}}
+  {{Discourse.globalNotice}}
   <div class="row">
     <div class="full-width">
 

app/assets/javascripts/discourse.js

@@ -143,7 +143,25 @@ window.Discourse = Ember.Application.createWithMixins(Discourse.Ajax, {
       }
     }
     return this.get("currentAssetVersion");
-  }.property()
+  }.property(),
+
+  globalNotice: function(){
+    var notices = [];
+
+    if(this.get("isReadOnly")){
+      notices.push(I18n.t("read_only_mode.enabled"));
+    }
+
+    if(!_.isEmpty(Discourse.SiteSettings.global_notice)){
+      notices.push(Discourse.SiteSettings.global_notice);
+    }
+
+    if(notices.length > 0) {
+      return new Handlebars.SafeString(_.map(notices, function(text) {
+        return "<div class='row'><div class='alert alert-info'>" + text + "</div></div>";
+      }).join(""));
+    }
+  }.property("isReadOnly")
 
 });
 

app/assets/javascripts/discourse/templates/discovery.js.handlebars

@@ -1,8 +1,6 @@
 <div class='container'>
   {{customHTML "top"}}
-  {{#if Discourse.isReadOnly}}
-    <div class="alert alert-info">{{i18n "read_only_mode.enabled"}}</div>
-  {{/if}}
+  {{Discourse.globalNotice}}
 </div>
 
 <div class='list-controls'>

app/assets/javascripts/discourse/templates/topic.js.handlebars

@@ -1,8 +1,6 @@
 <div class='container'>
   {{customHTML "top"}}
-  {{#if Discourse.isReadOnly}}
-    <div class="alert alert-info">{{i18n "read_only_mode.enabled"}}</div>
-  {{/if}}
+  {{Discourse.globalNotice}}
 </div>
 
 {{#if postStream.loaded}}

app/assets/javascripts/discourse/templates/user/user.js.handlebars

@@ -1,8 +1,6 @@
 <div class='container'>
   {{customHTML "top"}}
-  {{#if Discourse.isReadOnly}}
-    <div class="alert alert-info">{{i18n "read_only_mode.enabled"}}</div>
-  {{/if}}
+  {{Discourse.globalNotice}}
 </div>
 
 {{#unless loading}}

config/locales/server.en.yml

@@ -848,6 +848,8 @@ en:
     suppress_uncategorized_badge: "Don't show the badge for uncategorized topics in topic lists"
     min_posts_for_search_in_topic: "Disable search within topic if topics have less than minimum number posts"
 
+    global_notice: "Display a global banner to all users of the site, change to blank to hide it (HTML is allowed)"
+
     enable_names: "Allow users to show their full names"
     display_name_on_posts: "Also show a user's full name on their posts"
     invites_shown: "Maximum invites shown on a user page"

config/site_settings.yml

@@ -476,6 +476,10 @@ uncategorized:
   sequential_replies_threshold: 2
   dominating_topic_minimum_percent: 20
 
+  global_notice:
+    default: ""
+    client: true
+
   # Category IDs
   lounge_category_id:
     default: -1