Passing options to ActiveModel serializer - ruby-on-rails

Question

When using the serializer from the controller I can pass extra options to it like so
render json: user, some_option: 'foobar
Then I can reference some_option within the serializer as
serialization_options[:some_option]
But, if I call the serializer directly as
MySerializer.new(user, some_option: 'foobar')
I cannot get the extra options since serialization_options is an empty object.

Answer 1

For v0.9
You may call the following:
MySerializer.new(user).as_json({some_option: 'foobar'})
If you are doing that inside another serializer and you need to pass the scope and the current serialization_options as well, you can do this:
class MyParentSerializer
has_one :user
def user
MySerializer.new(object.user, { scope: scope }).as_json(serialization_options.merge({ some_option: 'foobar' }))
end
end

Answer 2

ActiveModel::Serializer's API has not really been consistent, in v0.9, however if you upgrade to v0.10, you could use the instance_options method to access the additional params. However, I'd be curious to learn how the objects were parsed in v0.9, though

Answer 3

Here is how you can pass parameters (options) from the parent serializer and show or hide attributes based on these parameters in the child serializer.
Parent serializer:
class LocationSharesSerializer < ActiveModel::Serializer
attributes :id, :locations, :show_title, :show_address
def locations
ActiveModelSerializers::SerializableResource.new(object.locations, {
each_serializer: PublicLocationSerializer,
params: {
show_title: object.show_title
},
})
end
end
Child serializer
class PublicLocationSerializer < ActiveModel::Serializer
attributes :id, :latitude, :longitude, :title, :directions, :description, :address, :tags, :created_at, :updated_at, :photos
def title
object.title if #instance_options[:params][:show_title]
end
end