From 03bc6f70f9e329e5df44df67e9f73c8e548e788a Mon Sep 17 00:00:00 2001
From: Robin Ward <robin.ward@gmail.com>
Date: Tue, 13 Dec 2016 14:37:37 -0500
Subject: [PATCH] Better error messages when embedding fails

---
 app/assets/stylesheets/embed.css.scss | 20 ++++++++++++++++++--
 app/controllers/embed_controller.rb   | 10 ++++++++++
 app/views/embed/embed_error.html.erb  | 25 +++++++++++++++++++++++++
 app/views/embed/loading.html.erb      |  8 ++++----
 config/locales/server.en.yml          |  5 +++++
 5 files changed, 62 insertions(+), 6 deletions(-)
 create mode 100644 app/views/embed/embed_error.html.erb

diff --git a/app/assets/stylesheets/embed.css.scss b/app/assets/stylesheets/embed.css.scss
index ae15f2cc66e..afb4a40c403 100644
--- a/app/assets/stylesheets/embed.css.scss
+++ b/app/assets/stylesheets/embed.css.scss
@@ -116,17 +116,33 @@ img.emoji {
   color: #999;
 }
 
+.clearfix {
+  clear: both;
+}
+
+
 header.discourse {
   padding-left: 10px;
+  padding-right: 10px;
   padding-bottom: 8px;
   font-size: 1.286em;
   border-bottom: 3px solid #ddd;
 
-  .button {
-    float:right;
+  display: flex;
+  flex-direction: row;
+  align-items: center;
+  justify-content: space-between;
+
+  h3 {
+    margin: 0 auto 0 0;
+    font-size: 1.0em;
   }
 }
 
+.embed-error {
+  padding: 0 10px;
+}
+
 footer {
   font-size: 1.286em;
   margin-top: 0.5em;
diff --git a/app/controllers/embed_controller.rb b/app/controllers/embed_controller.rb
index 3286eaead1b..9407f847f20 100644
--- a/app/controllers/embed_controller.rb
+++ b/app/controllers/embed_controller.rb
@@ -6,6 +6,16 @@ class EmbedController < ApplicationController
 
   layout 'embed'
 
+  rescue_from Discourse::InvalidAccess do
+    response.headers['X-Frame-Options'] = "ALLOWALL"
+    if current_user.try(:admin?)
+      @setup_url = "#{Discourse.base_url}/admin/customize/embedding"
+      @show_reason = true
+      @hosts = EmbeddableHost.all
+    end
+    render 'embed_error'
+  end
+
   def comments
     embed_url = params[:embed_url]
     embed_username = params[:discourse_username]
diff --git a/app/views/embed/embed_error.html.erb b/app/views/embed/embed_error.html.erb
new file mode 100644
index 00000000000..65f4c3c43df
--- /dev/null
+++ b/app/views/embed/embed_error.html.erb
@@ -0,0 +1,25 @@
+<header class='discourse'>
+  <h3><%= t 'embed.error' %></h3>
+  <%= link_to(image_tag(SiteSetting.logo_url, class: 'logo'), Discourse.base_url) %>
+  <div class='clearfix'></div>
+</header>
+<%- if @show_reason %>
+  <div class='embed-error'>
+    <%- if @hosts.present? %>
+      <p><%= t 'embed.referer' %><code><%= request.referer %></code></p>
+      <p><%= t 'embed.mismatch' %></p>
+
+      <ul>
+        <%- @hosts.each do |eh| %>
+          <li>
+            <%= eh.host %><%- if eh.path_whitelist.present? %><%= eh.path_whitelist %><% end %>
+          </li>
+        <%- end %>
+      </ul>
+    <%- else %>
+      <p><%= t 'embed.no_hosts' %></p>
+    <%- end %>
+
+    <p><%= link_to(t('embed.configure'), @setup_url, target: '_blank') %></p>
+  </div>
+<%- end %>
diff --git a/app/views/embed/loading.html.erb b/app/views/embed/loading.html.erb
index e4c6ccd5d98..2a5621de827 100644
--- a/app/views/embed/loading.html.erb
+++ b/app/views/embed/loading.html.erb
@@ -1,12 +1,12 @@
-<header>
-  <%= t 'embed.loading' %>
+<header class='discourse'>
+  <h3><%= t 'embed.loading' %></h3>
   <%= link_to(image_tag(SiteSetting.logo_url, class: 'logo'), Discourse.base_url) %>
+  <div class='clearfix'></div>
 </header>
-
 <script>
   (function() {
     setTimeout(function() {
       document.location.reload();
     }, 30000);
   })();
-</script>
\ No newline at end of file
+</script>
diff --git a/config/locales/server.en.yml b/config/locales/server.en.yml
index 81580737a2f..2260ce3ab94 100644
--- a/config/locales/server.en.yml
+++ b/config/locales/server.en.yml
@@ -158,6 +158,11 @@ en:
   embed:
     start_discussion: "Start Discussion"
     continue: "Continue Discussion"
+    error: "Error Embedding"
+    referer: "Referer:"
+    mismatch: "The referer did not match any of the following hosts:"
+    no_hosts: "No hosts were set up for embedding."
+    configure: "Configure Embedding"
     more_replies:
       one: "1 more reply"
       other: "%{count} more replies"