1 files changed, 16 insertions, 13 deletions

diff --git a/app/models/event.rb b/app/models/event.rb
index 94a22e3..26c79e4 100644
--- a/app/models/event.rb
+++ b/app/models/event.rb
@@ -1,22 +1,25 @@
 class Event < ApplicationRecord
-  
-  # Associations
-  
-  has_many    :occurrences
-  belongs_to  :node
-  
-  # Callbacks
-  
-  after_save  :generate_occurences
-  
-  # Instance Methods
-  
+
+  belongs_to :node, optional: true
+  has_many   :occurrences
+
+  validates :title, presence: true, unless: -> { node_id.present? }
+  validates :is_primary, uniqueness: { scope: :node_id,
+    message: "only one primary event per node allowed" },
+    if: -> { is_primary? && node_id.present? }
+
+  after_save :generate_occurences
+
   def occurrences_in_range start_time, end_time
     self.occurrences.where(
       "start_time > ? AND end_time < ?",
       start_time, end_time
     )
-  end 
+  end
+
+  def display_title
+    title.presence || node&.head&.title || "Untitled event"
+  end
 
   private
     def generate_occurences