Class: GraphQL::Schema::PossibleTypes

Inherits:
Object
  • Object
show all
Defined in:
lib/graphql/schema/possible_types.rb

Overview

Find the members of a union or interface within a given schema.

(Although its members never change, unions are handled this way to simplify execution code.)

Internally, the calculation is cached. It's assumed that schema members _don't_ change after creating the schema!

Examples:

Get an interface's possible types

possible_types = GraphQL::Schema::PossibleTypes(MySchema)
possible_types.possible_types(MyInterface)# => [MyObjectType, MyOtherObjectType]

Instance Method Summary collapse

Constructor Details

#initialize(schema) ⇒ PossibleTypes

Returns a new instance of PossibleTypes.


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# File 'lib/graphql/schema/possible_types.rb', line 15

def initialize(schema)
  @object_types = schema.types.values.select { |type| type.kind.object? }

  @interface_implementers = Hash.new do |hash, key|
    hash[key] = @object_types.select { |type| type.interfaces.include?(key) }.sort_by(&:name)
  end
end

Instance Method Details

#possible_types(type_defn) ⇒ Object


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# File 'lib/graphql/schema/possible_types.rb', line 23

def possible_types(type_defn)
  case type_defn
  when GraphQL::UnionType
    type_defn.possible_types
  when GraphQL::InterfaceType
    @interface_implementers[type_defn]
  when GraphQL::BaseType
    [type_defn]
  else
    raise "Unexpected possible_types object: #{type_defn}"
  end
end