Eventdate validation helpers and form errors

Add can_destroy? helper method, orm-level checks before
the eventdate is destroyed, and a validator to event so
trying to destroy an eventdate that has been billed for
raises an error.

Author: NoRePercussions

app/models/event.rb

@@ -69,7 +69,7 @@ class Event < ActiveRecord::Base
   validates_associated      :organization, :emails, :event_roles, :eventdates
   validates_format_of       :contactemail, :with => Event::EmailRegex, :multiline => true
   # validate :eventdate_valid?
-  validate :textable_social_valid?
+  validate :textable_social_valid?, :check_eventdates_to_be_destroyed
 
   scope :current_year, -> { where("representative_date >= ? or last_representative_date > ?", Account.magic_date, Account.magic_date) }
 
@@ -230,4 +230,17 @@ def textable_social_valid?
         errors.add(:textable_social, "Textable must be enabled if social textable is enabled")
       end
     end
+
+    def check_eventdates_to_be_destroyed
+      # If we are trying to update an event, someone might try to delete an eventdate.
+      # This is bad if someone has billed for it. There is before_destroy validation,
+      # and a foreign key check, but because the eventdate is removed from the event,
+      # it is not automatically validated on submission. This we must manually check
+      # that we can delete events here.
+      eventdates.each do |eventdate|
+        if eventdate.marked_for_destruction? and !eventdate.can_destroy?
+          errors.add(:eventdates, "Cannot delete an eventdate that has been billed for")
+        end
+      end
+    end
 end

app/models/eventdate.rb

@@ -18,6 +18,8 @@ class Eventdate < ApplicationRecord
   before_validation :prune_roles
   after_save :synchronize_representative_dates
 
+  before_destroy :check_can_destroy
+
   Event_Span_Days       = 2;
   Event_Span_Seconds    = Event_Span_Days * 24 * 60 * 60;
 
@@ -63,6 +65,17 @@ def valid_strike?
           ((strikedate.to_i - enddate.to_i) < Event_Span_Seconds))
   end
 
+  def can_destroy?
+    not self.timecard_entries.any?
+  end
+
+  def check_can_destroy
+    if not self.can_destroy?
+      errors.add(:base, "Cannot delete an eventdate that has been billed for")
+      throw(:abort)
+    end
+  end
+
   def has_call?
     self.calltype == "literal" or self.calltype == "startdate"
   end

app/models/timecard_entry.rb

@@ -6,7 +6,7 @@ class TimecardEntry < ApplicationRecord
   extend Enumerize
   enumerize :eventpart, in: ["call", "show", "strike"], default: "show"
 
-  validates_presence_of :eventdate, :member_id, :eventdate_id, :hours, :eventpart
+  validates_presence_of :eventdate, :member_id, :hours, :eventpart
   validates_numericality_of :hours, :less_than_or_equal_to => 37.5, :greater_than => 0
   validates_associated :member
   validates_inclusion_of :timecard, :in => ->(t){Timecard.valid_timecards}, :message => 'is not a current timecard', :allow_nil => true

app/views/events/_eventdate_fields.html.erb

@@ -108,10 +108,14 @@
   <% if can? :tic, @event %>
     <dl>
       <dt>Delete?</dt>
-      <% if @event.new_record? %>
-        <dd><%= link_to_remove_fields image_tag("cross.png"), f, true %></dd>
+      <% if f.object.can_destroy? %>
+        <% if @event.new_record? %>
+          <dd><%= link_to_remove_fields image_tag("cross.png"), f, true %></dd>
+        <% else %>
+          <dd><%= link_to_remove_fields image_tag("cross.png"), f %></dd>
+        <% end %>
       <% else %>
-        <dd><%= link_to_remove_fields image_tag("cross.png"), f %></dd>
+        <dd>You can't delete this date, as someone has already billed for it.</dd>
       <% end %>
     </dl>
   <% end %>