module Grape::Validations::Types::BuildCoercer

Public Class Methods

build_coercer(type, method: nil, strict: false) click to toggle source

Chooses the best coercer for the given type. For example, if the type is Integer, it will return a coercer which will be able to coerce a value to the integer.

There are a few very special coercers which might be returned.

Grape::Types::MultipleTypeCoercer is a coercer which is returned when the given type implies values in an array with different types. For example, +[Integer, String]+ allows integer and string values in an array.

Grape::Types::CustomTypeCoercer is a coercer which is returned when a method is specified by a user with coerce_with option or the user specifies a custom type which implements requirments of Grape::Types::CustomTypeCoercer.

Grape::Types::CustomTypeCollectionCoercer is a very similar to the previous one, but it expects an array or set of values having a custom type implemented by the user.

There is also a group of custom types implemented by Grape, check Grape::Validations::Types::SPECIAL to get the full list.

@param type [Class] the type to which input strings

should be coerced

@param method [Class,#call] the coercion method to use @return [Object] object to be used

for coercion and type validation
# File lib/grape/validations/types/build_coercer.rb, line 35
def self.build_coercer(type, method: nil, strict: false)
  cache_instance(type, method, strict) do
    create_coercer_instance(type, method, strict)
  end
end
cache_instance(type, method, strict) { || ... } click to toggle source
# File lib/grape/validations/types/build_coercer.rb, line 65
def self.cache_instance(type, method, strict, &_block)
  key = cache_key(type, method, strict)

  return @__cache[key] if @__cache.key?(key)

  instance = yield

  @__cache_write_lock.synchronize do
    @__cache[key] = instance
  end

  instance
end
cache_key(type, method, strict) click to toggle source
# File lib/grape/validations/types/build_coercer.rb, line 79
def self.cache_key(type, method, strict)
  [type, method, strict].each_with_object(+'_') do |val, memo|
    next if val.nil?

    memo << '_' << val.to_s
  end
end
create_coercer_instance(type, method, strict) click to toggle source
# File lib/grape/validations/types/build_coercer.rb, line 41
def self.create_coercer_instance(type, method, strict)
  # Maps a custom type provided by Grape, it doesn't map types wrapped by collections!!!
  type = Types.map_special(type)

  # Use a special coercer for multiply-typed parameters.
  if Types.multiple?(type)
    MultipleTypeCoercer.new(type, method)

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

    # Special coercer for collections of types that implement a parse method.
    # CustomTypeCoercer (above) already handles such types when an explicit coercion
    # method is supplied.
  elsif Types.collection_of_custom?(type)
    Types::CustomTypeCollectionCoercer.new(
      Types.map_special(type.first), type.is_a?(Set)
    )
  else
    DryTypeCoercer.coercer_instance_for(type, strict)
  end
end