Phase 1: standalone events, external_url on nodes

- Migration: node_id nullable on events and occurrences, add
  title/description/is_primary to events, external_url to nodes
- Existing events marked is_primary: true (were all 1:1 with nodes)
- Node: has_one :event -> has_many :events
- Event: belongs_to :node optional, validates title presence for
  standalone events, is_primary uniqueness scoped to node_id,
  display_title helper falling back through node title
- Occurrence: belongs_to :node optional, summary falls back to
  event.display_title
- nodes_helper: event_information uses events.first (interim; will
  be replaced in Phase 3 event UI)
- Tests: fix node.event -> node.events.first in event_test

1 files changed, 1 insertions, 1 deletions

diff --git a/app/models/node.rb b/app/models/node.rb
index 92ecc12..ba94e2a 100644
--- a/app/models/node.rb
+++ b/app/models/node.rb
@@ -7,7 +7,7 @@ class Node < ApplicationRecord
   belongs_to  :head,  :class_name => "Page",  :foreign_key => :head_id, :dependent => :destroy, optional: true
   belongs_to  :draft, :class_name => "Page",  :foreign_key => :draft_id, :dependent => :destroy, optional: true
   has_many    :permissions, :dependent => :destroy
-  has_one     :event, :dependent => :destroy
+  has_many    :events, :dependent => :destroy
   belongs_to  :lock_owner, :class_name => "User", :foreign_key => :locking_user_id, optional: true
 
   # Callbacks