Class: Grape::Validations::Types::CustomTypeCoercer

Inherits:
Object
  • Object
show all
Defined in:
lib/grape/validations/types/custom_type_coercer.rb

Overview

This class will detect type classes that implement a class-level +parse+ method. The method should accept one +String+ argument and should return the value coerced to the appropriate type. The method may raise an exception if there are any problems parsing the string.

Alternately an optional +method+ may be supplied (see the +coerce_with+ option of Dsl::Parameters#requires). This may be any class or object implementing +parse+ or +call+, with the same contract as described above.

Type Checking

Calls to +coerced?+ will consult this class to check that the coerced value produced above is in fact of the expected type. By default this class performs a basic check against the type supplied, but this behaviour will be overridden if the class implements a class-level +coerced?+ or +parsed?+ method. This method will receive a single parameter that is the coerced value and should return +true+ if the value meets type expectations. Arbitrary assertions may be made here but the grape validation system should be preferred.

Alternately a proc or other object responding to +call+ may be supplied in place of a type. This should implement the same contract as +coerced?+, and must be supplied with a coercion +method+.

Direct Known Subclasses

CustomTypeCollectionCoercer

Instance Method Summary collapse

Constructor Details

#initialize(type, method = nil) ⇒ CustomTypeCoercer

A new coercer for the given type specification and coercion method.

Parameters:

  • type (Class, #coerced?, #parsed?, #call?) —

    specifier for the target type. See class docs.

  • method (#parse, #call) (defaults to: nil) —

    optional coercion method. See class docs.



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# File 'lib/grape/validations/types/custom_type_coercer.rb', line 43

def initialize(type, method = nil)
  coercion_method = infer_coercion_method type, method
  @method = enforce_symbolized_keys type, coercion_method
  @type_check = infer_type_check(type)
end

Instance Method Details

#call(val) ⇒ Object

Coerces the given value.

Parameters:

  • value (String) —

    value to be coerced, in grape this should always be a string.

Returns:

  • (Object) —

    the coerced result



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# File 'lib/grape/validations/types/custom_type_coercer.rb', line 54

def call(val)
  coerced_val = @method.call(val)

  return coerced_val if coerced_val.is_a?(InvalidValue)
  return InvalidValue.new unless coerced?(coerced_val)

  coerced_val
end

#coerced?(val) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/grape/validations/types/custom_type_coercer.rb', line 63

def coerced?(val)
  val.nil? || @type_check.call(val)
end