Class: ActiveSnapshot::Snapshot

Inherits:
ActiveRecord::Base
  • Object
show all
Defined in:
lib/active_snapshot/models/snapshot.rb

Instance Method Summary collapse

Instance Method Details

#build_snapshot_item(instance, child_group_name: nil) ⇒ Object 



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# File 'lib/active_snapshot/models/snapshot.rb', line 33

def build_snapshot_item(instance, child_group_name: nil)
  self.snapshot_items.new({
    object: instance.attributes, 
    item_id: instance.id,
    item_type: instance.class.name,
    child_group_name: child_group_name,
  })
end

#fetch_reified_items ⇒ Object 



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# File 'lib/active_snapshot/models/snapshot.rb', line 84

def fetch_reified_items
  reified_children_hash = {}.with_indifferent_access

  reified_parent = nil

  snapshot_items.each do |si| 
    reified_item = si.item_type.constantize.new(si.object)

    reified_item.readonly!

    key = si.child_group_name

    if key
      reified_children_hash[key] ||= []

      reified_children_hash[key] << reified_item

    elsif [self.item_id, self.item_type] == [si.item_id, si.item_type]
      reified_parent = reified_item
    end
  end

  return [reified_parent, reified_children_hash]
end

#metadata ⇒ Object 



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# File 'lib/active_snapshot/models/snapshot.rb', line 18

def metadata
  yaml_method = "unsafe_load"

  if !YAML.respond_to?("unsafe_load")
    yaml_method = "load"
  end

  @metadata ||= YAML.send(yaml_method, self[:metadata]).with_indifferent_access
end

#metadata=(h) ⇒ Object 



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# File 'lib/active_snapshot/models/snapshot.rb', line 28

def metadata=(h)
  @metadata = nil
  self[:metadata] = YAML.dump(h)
end

#restore! ⇒ Object 



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# File 'lib/active_snapshot/models/snapshot.rb', line 42

def restore!
  ActiveRecord::Base.transaction do
    ### Cache the child snapshots in a variable for re-use
    cached_snapshot_items = snapshot_items.includes(:item)

    existing_snapshot_children = item ? item.children_to_snapshot : []

    if existing_snapshot_children.any?
      children_to_keep = Set.new

      cached_snapshot_items.each do |snapshot_item|
        key = "#{snapshot_item.item_type} #{snapshot_item.item_id}"

        children_to_keep << key
      end

      ### Destroy or Detach Items not included in this Snapshot's Items
      ### We do this first in case you later decide to validate children in ItemSnapshot#restore_item! method
      existing_snapshot_children.each do |child_group_name, h|
        delete_method = h[:delete_method] || ->(child_record){ child_record.destroy! }

        h[:records].each do |child_record|
          child_record_id = child_record.send(child_record.class.send(:primary_key))

          key = "#{child_record.class.name} #{child_record_id}"

          if children_to_keep.exclude?(key)
            delete_method.call(child_record)
          end
        end
      end
    end

    ### Create or Update Items from Snapshot Items
    cached_snapshot_items.each do |snapshot_item|
      snapshot_item.restore_item!
    end
  end

  return true
end