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
]
STRUCTURES =

Types representing data structures.

[
  Hash,
  Array,
  Set
]
SPECIAL =

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

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

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



22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
 
# 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 = type

  # 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



149
150
151
152
153
154
155
156
157
 
# 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

Parameters:

  • type (Array<Class>, Class) —

    type to check

Returns:

  • (Boolean) —

    true if the type is a supported group type



141
142
143
 
# 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.



102
103
104
 
# 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



78
79
80
 
# 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



117
118
119
120
121
122
123
 
# 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



132
133
134
 
# 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



90
91
92
 
# File 'lib/grape/validations/types.rb', line 90

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