Configuration

Set config in a base serializer. Child serializers inherit it and can change it.

class AppSerializer < Serega
  config.auto_preload = true
  config.hide_by_default = :auto
  config.base_serializer = self
end

Set config before defining attributes. An attribute reads the config when it is defined, so a later change to auto_preload, hide_by_default, batch_id_option or base_serializer affects only attributes defined after it.

Options

Option	Default	Description
`auto_preload`	`false`	Adds [preloads][automatic-preloads] to `:delegate` and `:serializer` attributes
`auto_preload_excluded_methods`	`[:itself, :__getobj__]`	Methods never preloaded automatically
`hide_by_default`	`false`	Hides attributes, see Hiding by default
`base_serializer`	`nil`	Superclass of [block-defined serializers][block-serializers]
`batch_id_option`	`:id`	Method that returns the id of an object for batch loaders
`delegate_default_allow_nil`	`false`	Default `allow_nil:` of delegates
`hash_access.default_mode`	`:symbol`	Mode of `hash_access: true`. See Hash records
`hash_access.default_allow_missing_key`	`false`	`nil` for missing Hash keys
`check_attribute_name`	`true`	Allows only `a-z`, `A-Z`, `0-9`, `_`, `-`, `~` in attribute names
`require_many`	`false`	Requires `:many` on relations
`check_initiate_params`	`true`	Raises on unknown fields in `:only`, `:except`, `:with`
`max_cached_plans_per_serializer_count`	`20`	Serialization plans cached per serializer, `0` disables the cache
`depth_limit`	`nil`	Deepest nesting of serialized fields, see Depth limit

Depth limit

config.depth_limit guards against expensive requests and cyclic relations. The limit of the serializer that starts the serialization applies to all nested serializers.

class AppSerializer < Serega
  config.depth_limit = 10
end

class UserSerializer < AppSerializer
  config.depth_limit = 2
  attribute :friends, serializer: -> { UserSerializer }, hide: true
end

UserSerializer.to_h(user, with: :friends) # depth 2
UserSerializer.to_h(user, with: {friends: :friends})
# => Serega::DepthLimitError: Depth limit was exceeded

Serega::DepthLimitError#details shows the path: UserSerializer (depth limit: 2) -> friends -> friends.

The limit is checked when the serialization plan is built, before any serialization. Call UserSerializer.new(with: params[:with]) early to validate a request before running other code.

Plan cache

A serialization plan lists the fields to serialize. Serega caches plans by the :only, :except and :with options as given, so [:id, :name] and "id,name" are cached separately. The plan without these options is always cached.

config.root and config.context_metadata are described in Root Key and Metadata.