Class: GraphQL::NonNullType

Inherits:
BaseType show all
Extended by:
Delegate
Includes:
BaseType::ModifiesAnotherType
Defined in:
lib/graphql/non_null_type.rb

Overview

A non-null type modifies another type.

Non-null types can be created with ! (InnerType!) or BaseType#to_non_null_type (InnerType.to_non_null_type)

For return types, it says that the returned value will always be present.

(If the application fails to return a value, InvalidNullError will be passed to Schema#type_error.)

For input types, it says that the incoming value must be provided by the query.

(If a value isn't provided, Query::VariableValidationError will be raised).

Given a non-null type, you can always get the underlying type with BaseType::ModifiesAnotherType#unwrap.

Examples:

A field which always returns an error

field :items, !ItemType
# or
field :items, ItemType.to_non_null_type

A field which requires a string input

field :newNames do
  # ...
  argument :values, !types.String
  # or
  argument :values, types.String.to_non_null_type
end

Instance Attribute Summary collapse

Attributes inherited from BaseType

#default_relay, #default_scalar, #description, #introspection, #name

Instance Method Summary collapse

Methods included from Delegate

def_delegators

Methods included from BaseType::ModifiesAnotherType

#unwrap

Methods inherited from BaseType

#==, #coerce_input, #coerce_isolated_input, #coerce_isolated_result, #coerce_result, #connection_type, #default_relay?, #default_scalar?, #define_connection, #define_edge, #edge_type, #get_field, #initialize_copy, #introspection?, resolve_related_type, #resolve_type, #to_definition, #to_list_type, #to_non_null_type, #unwrap, #valid_isolated_input?, #validate_isolated_input

Methods included from Define::InstanceDefinable

#define, #initialize_copy, #metadata, #redefine

Methods included from Define::NonNullWithBang

#!

Constructor Details

#initialize(of_type:) ⇒ NonNullType

Returns a new instance of NonNullType.



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# File 'lib/graphql/non_null_type.rb', line 39

def initialize(of_type:)
  if of_type.is_a?(GraphQL::NonNullType)
    raise(
      DoubleNonNullTypeError,
      "You tried to add a non-null constraint twice (!! instead of !)"
    )
  end

  super()
  @of_type = of_type
end

Instance Attribute Details

#of_type ⇒ Object (readonly)

Returns the value of attribute of_type.



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# File 'lib/graphql/non_null_type.rb', line 38

def of_type
  @of_type
end

Instance Method Details

#kind ⇒ Object 



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# File 'lib/graphql/non_null_type.rb', line 67

def kind
  GraphQL::TypeKinds::NON_NULL
end

#to_s ⇒ Object Also known as: inspect 



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# File 'lib/graphql/non_null_type.rb', line 71

def to_s
  "#{of_type.to_s}!"
end

#valid_input?(value, ctx) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/graphql/non_null_type.rb', line 51

def valid_input?(value, ctx)
  validate_input(value, ctx).valid?
end

#validate_input(value, ctx) ⇒ Object 



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# File 'lib/graphql/non_null_type.rb', line 55

def validate_input(value, ctx)
  if value.nil?
    result = GraphQL::Query::InputValidationResult.new
    result.add_problem("Expected value to not be null")
    result
  else
    of_type.validate_input(value, ctx)
  end
end