module JSON::HashValueConverter(Converter)

Overview

Converter to be used with JSON::Serializable to serialize the values of a Hash(String, V) with the custom converter.

require "json"

class TimestampHash
  include JSON::Serializable

  @[JSON::Field(converter: JSON::HashValueConverter(Time::EpochConverter))]
  property birthdays : Hash(String, Time)
end

timestamp = TimestampHash.from_json(%({"birthdays":{"foo":1459859781,"bar":1567628762}}))
timestamp.birthdays # => {"foo" => 2016-04-05 12:36:21 UTC, "bar" => 2019-09-04 20:26:02 UTC}
timestamp.to_json   # => %({"birthdays":{"foo":1459859781,"bar":1567628762}})

JSON::HashValueConverter.new should be used if the nested converter is also an instance instead of a type.

require "json"

class TimestampHash
  include JSON::Serializable

  @[JSON::Field(converter: JSON::HashValueConverter.new(Time::Format.new("%b %-d, %Y")))]
  property birthdays : Hash(String, Time)
end

timestamp = TimestampHash.from_json(%({"birthdays":{"foo":"Apr 5, 2016","bar":"Sep 4, 2019"}}))
timestamp.birthdays # => {"foo" => 2016-04-05 00:00:00 UTC, "bar" => 2019-09-04 00:00:00 UTC}
timestamp.to_json   # => %({"birthdays":{"foo":"Apr 5, 2016","bar":"Sep 4, 2019"}})

This implies that JSON::HashValueConverter(T) and JSON::HashValueConverter(T.class).new(T) perform the same serializations.

Defined in:

json/from_json.cr
json/to_json.cr

Constructors

• .new(converter : Converter)

Class Method Summary

• .from_json(pull : JSON::PullParser)
• .to_json(values : Hash, builder : JSON::Builder)

Constructor Detail

Class Method Detail