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rails--rails/activemodel/lib/active_model/serialization.rb

116 lines
3.5 KiB
Ruby

require 'active_support/core_ext/hash/except'
require 'active_support/core_ext/hash/slice'
require 'active_support/core_ext/array/wrap'
module ActiveModel
# == Active Model Serialization
#
# Provides a basic serialization to a serializable_hash for your object.
#
# A minimal implementation could be:
#
# class Person
#
# include ActiveModel::Serialization
#
# attr_accessor :name
#
# def attributes
# {'name' => name}
# end
#
# end
#
# Which would provide you with:
#
# person = Person.new
# person.serializable_hash # => {"name"=>nil}
# person.name = "Bob"
# person.serializable_hash # => {"name"=>"Bob"}
#
# You need to declare some sort of attributes hash which contains the attributes
# you want to serialize and their current value.
#
# Most of the time though, you will want to include the JSON or XML
# serializations. Both of these modules automatically include the
# ActiveModel::Serialization module, so there is no need to explicitly
# include it.
#
# So a minimal implementation including XML and JSON would be:
#
# class Person
#
# include ActiveModel::Serializers::JSON
# include ActiveModel::Serializers::Xml
#
# attr_accessor :name
#
# def attributes
# {'name' => name}
# end
#
# end
#
# Which would provide you with:
#
# person = Person.new
# person.serializable_hash # => {"name"=>nil}
# person.as_json # => {"name"=>nil}
# person.to_json # => "{\"name\":null}"
# person.to_xml # => "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<serial-person...
#
# person.name = "Bob"
# person.serializable_hash # => {"name"=>"Bob"}
# person.as_json # => {"name"=>"Bob"}
# person.to_json # => "{\"name\":\"Bob\"}"
# person.to_xml # => "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<serial-person...
#
# Valid options are <tt>:only</tt>, <tt>:except</tt> and <tt>:methods</tt> .
module Serialization
def serializable_hash(options = nil)
options ||= {}
attribute_names = attributes.keys.sort
if only = options[:only]
attribute_names &= Array.wrap(only).map(&:to_s)
elsif except = options[:except]
attribute_names -= Array.wrap(except).map(&:to_s)
end
method_names = Array.wrap(options[:methods]).select { |n| respond_to?(n) }
hash = Hash[(attribute_names + method_names).map { |n| [n, send(n)] }]
serializable_add_includes(options) do |association, records, opts|
hash[association] = if records.is_a?(Enumerable)
records.map { |a| a.serializable_hash(opts) }
else
records.serializable_hash(opts)
end
end
hash
end
private
# Add associations specified via the <tt>:include</tt> option.
#
# Expects a block that takes as arguments:
# +association+ - name of the association
# +records+ - the association record(s) to be serialized
# +opts+ - options for the association records
def serializable_add_includes(options = {})
return unless include = options[:include]
unless include.is_a?(Hash)
include = Hash[Array.wrap(include).map { |n| [n, {}] }]
end
include.each do |association, opts|
if records = send(association)
yield association, records, opts
end
end
end
end
end