Method: GraphQL::Schema#resolve_type

Defined in:
lib/graphql/schema.rb

#resolve_type(type, object, ctx = :__undefined__) ⇒ GraphQL::ObjectType

Determine the GraphQL type for a given object. This is required for unions and interfaces (including Relay's Node interface)

Parameters:

  • type (GraphQL::UnionType, GraphQL:InterfaceType) —

    the abstract type which is being resolved

  • object (Any) —

    An application object which GraphQL is currently resolving on

  • ctx (GraphQL::Query::Context) (defaults to: :__undefined__) —

    The context for the current query

Returns:

See Also:

  • Restricted access to members of a schema


388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
 
# File 'lib/graphql/schema.rb', line 388

def resolve_type(type, object, ctx = :__undefined__)
  if ctx == :__undefined__
    # Old method signature
    ctx = object
    object = type
    type = nil
  end

  # Prefer a type-local function; fall back to the schema-level function
  type_proc = type && type.resolve_type_proc
  type_result = if type_proc
    type_proc.call(object, ctx)
  else
    if @resolve_type_proc.nil?
      raise(NotImplementedError, "Can't determine GraphQL type for: #{object.inspect}, define `resolve_type (type, obj, ctx) -> { ... }` inside `Schema.define`.")
    end
    @resolve_type_proc.call(type, object, ctx)
  end

  if type_result.nil?
    nil
  elsif !type_result.is_a?(GraphQL::BaseType)
    type_str = "#{type_result} (#{type_result.class.name})"
    raise "resolve_type(#{object}) returned #{type_str}, but it should return a GraphQL type"
  else
    type_result
  end
end