Module: Grape::Validations::Types

Defined in:
lib/grape/validations/types.rb,
lib/grape/validations/types/file.rb,
lib/grape/validations/types/json.rb,
lib/grape/validations/types/build_coercer.rb,
lib/grape/validations/types/custom_type_coercer.rb,
lib/grape/validations/types/multiple_type_coercer.rb,
lib/grape/validations/types/variant_collection_coercer.rb

Overview

Module for code related to grape's system for coercion and type validation of incoming request parameters.

Grape uses a number of tests and assertions to work out exactly how a parameter should be handled, based on the +type+ and +coerce_with+ options that may be supplied to Dsl::Parameters#requires and Dsl::Parameters#optional. The main entry point for this process is Types.build_coercer.

Defined Under Namespace

Classes: CustomTypeCoercer, File, InvalidValue, Json, JsonArray, MultipleTypeCoercer, VariantCollectionCoercer

Constant Summary collapse

PRIMITIVES =

Types representing a single value, which are coerced through Virtus or special logic in Grape.

[
  # Numerical
  Integer,
  Float,
  BigDecimal,
  Numeric,

  # Date/time
  Date,
  DateTime,
  Time,

  # Misc
  Virtus::Attribute::Boolean,
  String,
  Symbol,
  Rack::Multipart::UploadedFile
].freeze
STRUCTURES =

Types representing data structures.

[
  Hash,
  Array,
  Set
].freeze
SPECIAL =

Types for which Grape provides special coercion and type-checking logic.

{
  JSON => Json,
  Array[JSON] => JsonArray,
  ::File => File,
  Rack::Multipart::UploadedFile => File
}.freeze
GROUPS =
[
  Array,
  Hash,
  JSON,
  Array[JSON]
].freeze

Class Method Summary collapse

Class Method Details

.build_coercer(type, method = nil) ⇒ Virtus::Attribute

Work out the +Virtus::Attribute+ object to use for coercing strings to the given +type+. Coercion +method+ will be inferred if none is supplied.

If a +Virtus::Attribute+ object already built with +Virtus::Attribute.build+ is supplied as the +type+ it will be returned and +method+ will be ignored.

See CustomTypeCoercer for further details about coercion and type-checking inference.

Parameters:

  • type (Class)

    the type to which input strings should be coerced

  • method (Class, #call) (defaults to: nil)

    the coercion method to use

Returns:

  • (Virtus::Attribute)

    object to be used for coercion and type validation



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# File 'lib/grape/validations/types/build_coercer.rb', line 22

def self.build_coercer(type, method = nil)
  # Accept pre-rolled virtus attributes without interference
  return type if type.is_a? Virtus::Attribute

  converter_options = {
    nullify_blank: true
  }
  conversion_type = if method == JSON
                      Object
                      # because we want just parsed JSON content:
                      # if type is Array and data is `"{}"`
                      # result will be [] because Virtus converts hashes
                      # to arrays
                    else
                      type
                    end

  # Use a special coercer for multiply-typed parameters.
  if Types.multiple?(type)
    converter_options[:coercer] = Types::MultipleTypeCoercer.new(type, method)
    conversion_type = Object

  # Use a special coercer for custom types and coercion methods.
  elsif method || Types.custom?(type)
    converter_options[:coercer] = Types::CustomTypeCoercer.new(type, method)

  # Grape swaps in its own Virtus::Attribute implementations
  # for certain special types that merit first-class support
  # (but not if a custom coercion method has been supplied).
  elsif Types.special?(type)
    conversion_type = Types::SPECIAL[type]
  end

  # Virtus will infer coercion and validation rules
  # for many common ruby types.
  Virtus::Attribute.build(conversion_type, converter_options)
end

.custom?(type) ⇒ Boolean

A valid custom type must implement a class-level parse method, taking one String argument and returning the parsed value in its correct type.

Parameters:

  • type (Class)

    type to check

Returns:

  • (Boolean)

    whether or not the type can be used as a custom type



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# File 'lib/grape/validations/types.rb', line 149

def self.custom?(type)
  !primitive?(type) &&
    !structure?(type) &&
    !multiple?(type) &&
    !recognized?(type) &&
    !special?(type) &&
    type.respond_to?(:parse) &&
    type.method(:parse).arity == 1
end

.group?(type) ⇒ Boolean

Is the declared type a supported group type? Currently supported group types are Array, Hash, JSON, and Array[JSON]

Parameters:

  • type (Array<Class>, Class)

    type to check

Returns:

  • (Boolean)

    +true+ if the type is a supported group type



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# File 'lib/grape/validations/types.rb', line 141

def self.group?(type)
  GROUPS.include? type
end

.multiple?(type) ⇒ Boolean

Is the declared type in fact an array of multiple allowed types? For example the declaration +types: [Integer,String]+ will attempt first to coerce given values to integer, but will also accept any other string.

Parameters:

  • type (Array<Class>, Set<Class>)

    type (or type list!) to check

Returns:

  • (Boolean)

    +true+ if the given value will be treated as a list of types.



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# File 'lib/grape/validations/types.rb', line 102

def self.multiple?(type)
  (type.is_a?(Array) || type.is_a?(Set)) && type.size > 1
end

.primitive?(type) ⇒ Boolean

Is the given class a primitive type as recognized by Grape?

Parameters:

  • type (Class)

    type to check

Returns:

  • (Boolean)

    whether or not the type is known by Grape as a valid type for a single value



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# File 'lib/grape/validations/types.rb', line 78

def self.primitive?(type)
  PRIMITIVES.include?(type)
end

.recognized?(type) ⇒ Boolean

Does the given class implement a type system that Grape (i.e. the underlying virtus attribute system) supports out-of-the-box? Currently supported are +axiom-types+ and +virtus+.

The type will be passed to +Virtus::Attribute.build+, and the resulting attribute object will be expected to respond correctly to +coerce+ and +value_coerced?+.

Parameters:

  • type (Class)

    type to check

Returns:

  • (Boolean)

    +true+ where the type is recognized



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# File 'lib/grape/validations/types.rb', line 117

def self.recognized?(type)
  return false if type.is_a?(Array) || type.is_a?(Set)

  type.is_a?(Virtus::Attribute) ||
    type.ancestors.include?(Axiom::Types::Type) ||
    type.include?(Virtus::Model::Core)
end

.special?(type) ⇒ Boolean

Does Grape provide special coercion and validation routines for the given class? This does not include automatic handling for primitives, structures and otherwise recognized types. See SPECIAL.

Parameters:

  • type (Class)

    type to check

Returns:

  • (Boolean)

    +true+ if special routines are available



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# File 'lib/grape/validations/types.rb', line 132

def self.special?(type)
  SPECIAL.key? type
end

.structure?(type) ⇒ Boolean

Note:

This method does not yet consider 'complex types', which inherit Virtus.model.

Is the given class a standard data structure (collection or map) as recognized by Grape?

Parameters:

  • type (Class)

    type to check

Returns:

  • (Boolean)

    whether or not the type is known by Grape as a valid data structure type



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# File 'lib/grape/validations/types.rb', line 90

def self.structure?(type)
  STRUCTURES.include?(type)
end