Partials

Partials allow you to compose views from reusable components. Just like views, partials can define fields, options, views, other partials, formatters, and extensions.

class WidgetBlueprint < ApplicationBlueprint
  field :name

  view :foo do
    use :associations
    field :foo
  end

  view :bar do
    use :associations, :description
    field :bar
  end

  partial :associations do
    object :category, CategoryBlueprint
    collection :parts, PartBlueprint
  end

  partial :description do
    field :description
  end
end

There are two ways of including partials: appending with ‘use’ and inserting with ‘use!’ (see examples).

Append with ‘use’

Partials are appended to your view, giving them the opportunity to override your view’s fields, options, etc. Precedence (highest to lowest) is:

1. Definitions in the partial
2. Definitions in the view
3. Definitions inherited from the blueprint/parent views

Insert with ‘use!’

Partials are embedded immediately, on that line, allowing subsequent lines to override the partial. Precedence (highest to lowest) is:

1. Definitions in the view after use!
2. Definitions in the partial
3. Definitions in the view before use!
4. Definitions inherited from the blueprint/parent views

Examples of ‘use’ and ‘use!’

partial :no_empty_fields do
  options[:field_if] = :og_field_logic
  # other stuff
end

# :foo appends the partial, so it overrides the view's field_if
view :foo do
  use :no_empty_fields
  options[:field_if] = :other_field_logic
end

# :bar inserts the partial, but the next line overrides the partial's field_if
view :bar do
  use! :no_empty_fields
  options[:field_if] = :other_field_logic
end