Allow changing the visibitly (public/privat) of messages (fixes #625)

plugins/messages/app/controllers/messages_controller.rb

@@ -48,6 +48,16 @@ class MessagesController < ApplicationController
     end
   end
 
+  def toggle_private
+    message = Message.find(params[:id])
+    if message.can_toggle_private?(current_user)
+      message.update_attribute :private, !message.private
+      redirect_to message
+    else
+      redirect_to message, alert: I18n.t('messages.toggle_private.not_allowed')
+    end
+  end
+
   def thread
     @messages = Message.thread(params[:id]).order(:created_at)
   end

plugins/messages/app/models/message.rb

@@ -124,6 +124,12 @@ class Message < ApplicationRecord
     !private || sender == user || recipients_ids.include?(user.id)
   end
 
+  def can_toggle_private?(user)
+    return true if sender == user
+    return false if private?
+    user.role_admin?
+  end
+
   private
 
   def create_salt

plugins/messages/app/views/messages/show.haml

@@ -23,6 +23,15 @@
     %tr
       %td= t '.sent_on'
       %td= format_time(@message.created_at)
+    %tr
+      %td= t '.visibility'
+      %td
+        - if @message.private
+          = t '.visibility_private'
+        - else
+          = t '.visibility_public'
+        - if @message.can_toggle_private?(current_user)
+          = link_to t('.change_visibility'), toggle_private_message_path(@message), method: :post, class: 'btn btn-mini'
   %hr/
   %p= simple_format(h(@message.body))
   %hr/