Module: EcsRails::Lazy::Component

Extended by:
ActiveSupport::Concern
Included in:
Component
Defined in:
lib/ecs_rails/lazy.rb

Overview

Mixed into EcsRails::Component.

Instance Method Summary collapse

Instance Method Details

#ecs_dirty? ⇒ Boolean

Does this component deserve a row?

RFC-0006 defines dirty as “at least one attribute differs from its default”, explicitly not ActiveModel’s “differs from the last saved value”. Both halves of that matter, and neither is quite what it looks like:

  1. ActiveModel’s dirty cannot be used for a component with no row. Building a virtual component sets entity_id, and ActiveModel counts that as a change — so user.email.changed? is true for a component nobody has touched, and a cascade built on it would insert a row for every component ever read. That is the whole feature, inverted.

  2. RFC-0006’s own wording fails for the same reason, taken literally: entity_id differs from its column default (nil) on every virtual component too. The foreign key is identity, not state — it says which entity this is, never anything about it — so the comparison has to skip it, and the primary key with it. See #state_attribute?.

  3. “Differs from default” is only the right question while there is no row. Once there is one, the question is ActiveModel’s, because the row now has a value to differ from: clearing an attribute back to its default is an UPDATE, and answering “not dirty” would silently discard it. This is where the two definitions genuinely part company, and the RFC’s destroy-then-reset case is the same split seen from the other side.

Returns:

  • (Boolean) 


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# File 'lib/ecs_rails/lazy.rb', line 210

def ecs_dirty?
  return changed? if persisted?

  self.class.column_defaults.any? do |attribute, default|
    next false unless state_attribute?(attribute)

    read_attribute(attribute) != default
  end
end