Partials

Partials allow you to compose your Blueprints and views from reusable pieces.

class MyBlueprint < ApplicationBlueprint
  view :view_1 do
    use :common_associations
    # ...
  end

  view :view_2 do
    use :common_associations
    # ...
  end
  
  partial :common_associations do
    association :foo, FooBlueprint
    association :bar, [BarBlueprint]
  end
end

You may only use partials defined in the current Blueprint/view (or a parent). To share code across completely separate Blueprints, use modules.

See the Blueprinter::V2::DSL docs for more info on partial and use.

More than just fields

Partials have access to the full DSL, so they can set options, add extensions, formatters, views, and even other partials.

class ApplicationBlueprint < Blueprinter::V2::Base
  partial :exclude_nil_or_blank do
    # Enable the built-in "skip if nil" option
    set :exclude_if_nil, true

    # Add an inline extension to skip blank fields
    extension do
      def around_field_value(ctx)
        val = yield ctx
        skip! if val.blank?
        val
      end
    end
  end
end

Blueprints or views that use the above partial will skip any nil or blank fields:

class MyBlueprint < ApplicationBlueprint
  use :exclude_nil_or_blank
end