5 files changed, 40 insertions, 2 deletions

diff --git a/app/controllers/nodes_controller.rb b/app/controllers/nodes_controller.rb
index 5b919b1f..22606674 100644
--- a/app/controllers/nodes_controller.rb
+++ b/app/controllers/nodes_controller.rb
@@ -116,7 +116,8 @@ class NodesController < ApplicationController
   rescue LockedByAnotherUser => e
     flash[:error] = e.message
     redirect_to node_path(@node)
-  rescue ActiveRecord::RecordInvalid
+  rescue ActiveRecord::RecordInvalid => e
+    flash.now[:error] = e.record.errors.full_messages.to_sentence
     @page = @node.autosave || @node.draft || @node.head
     render :action => :edit
   end
diff --git a/app/helpers/node_actions_helper.rb b/app/helpers/node_actions_helper.rb
index 4cf990b8..c4de46cc 100644
--- a/app/helpers/node_actions_helper.rb
+++ b/app/helpers/node_actions_helper.rb
@@ -28,7 +28,8 @@ module NodeActionsHelper
     "admin_revoke"       => "shield-minus",
     "event_create"       => "calendar-plus",
     "event_update"       => "calendar-event",
-    "event_destroy"      => "calendar-x"
+    "event_destroy"      => "calendar-x",
+    "node_external_url"  => "world"
   }.freeze
 
   def verb_icon action
@@ -64,6 +65,7 @@ module NodeActionsHelper
     return true if m["translation_diff"].present?
     return true if m["changes"].present? || m["description_changed"]
     return true if m["title"].is_a?(Hash) && m.dig("title", "from") != m.dig("title", "to")
+    return true if m["external_url"].present?
     %w[author tags template_changed assets assets_changed assets_reordered
        abstract_changed body_changed].any? { |key| m[key].present? }
   end
@@ -95,6 +97,9 @@ module NodeActionsHelper
     end
     items << t("node_actions.assets_reordered") if m["assets_reordered"]
     items << t("node_actions.assets_changed")   if m["assets_changed"]
+    items << t("node_actions.detail_external_url",
+            :from => m.dig("external_url", "from").presence || t("node_actions.event_none"),
+            :to   => m.dig("external_url", "to").presence   || t("node_actions.event_none")) if m["external_url"]
     items
   end
 
@@ -400,6 +405,11 @@ module NodeActionsHelper
     event_sentence(action, "event_destroy")
   end
 
+  def summarize_node_external_url action
+    t("node_actions.node_external_url", :actor => actor_ref(action),
+       :subject => subject_ref(action)).html_safe
+  end
+
   def event_sentence action, key
     if action.node
       t("node_actions.#{key}_on", :actor => actor_ref(action),
diff --git a/app/models/node.rb b/app/models/node.rb
index f8c29b48..4b7c9772 100644
--- a/app/models/node.rb
+++ b/app/models/node.rb
@@ -42,6 +42,9 @@ class Node < ApplicationRecord
             :inclusion   => { :in => ->(_) { Page.custom_templates } },
             :allow_blank => true,
             :if          => :default_template_name_changed?
+  validates :external_url, :format => { :with => %r{\Ahttps?://}i,
+                                        :allow_blank => true,
+                                        :message => :must_be_http }
 
   # Everything outside the Trash subtree, the Trash node included.
   # Relies on unique_name being authoritative for tree position --
@@ -605,6 +608,23 @@ class Node < ApplicationRecord
     self.created_at < new_id_format_date ? unique_path : id
   end
 
+  def update_external_url!(url, current_user = nil)
+    normalised = url.presence
+    return false if normalised == external_url
+
+    guard_live_change!(current_user)
+    previous = external_url
+
+    transaction do
+      update!(:external_url => normalised)
+      NodeAction.record!(:node => self, :user => current_user,
+                         :action => "node_external_url",
+                         :path => unique_name,
+                         :external_url => { "from" => previous, "to" => normalised })
+    end
+    true
+  end
+
   # Full-text search across all locale translations using PostgreSQL tsvector.
   # Uses 'simple' dictionary (no stemming, no stopwords) so queries work
   # across German and English content without language detection.
diff --git a/app/models/node_action.rb b/app/models/node_action.rb
index bfa469b1..f1e4eaea 100644
--- a/app/models/node_action.rb
+++ b/app/models/node_action.rb
@@ -134,6 +134,7 @@ class NodeAction < ApplicationRecord
   #                    from the node verbs' "tags", which is a pair,
   #                    so one renderer cannot mistake the other.
   #   "path"        -- the node's unique_name, when it has a node
+  #   "external_url" -- pair
   #
   # On "event_update" only, and only when something changed -- an
   # update that changes nothing records no entry at all:
diff --git a/app/views/nodes/edit.html.erb b/app/views/nodes/edit.html.erb
index b65416e1..c153c241 100644
--- a/app/views/nodes/edit.html.erb
+++ b/app/views/nodes/edit.html.erb
@@ -114,6 +114,12 @@
            %>
         </div>
 
+        <div class="layout_row_label"><%= t(".external_url") %></div>
+        <div class="layout_row_content">
+          <%= f.text_field :external_url %>
+          <p class="field_hint"><%= t(".external_url_hint") %></p>
+        </div>
+
         <div class="layout_row_label"><%= t(".tags") %></div>
         <div class="layout_row_content">
           <%= text_field_tag :tag_list, @page.tag_list.join(', ') %>