require 'active_support/core_ext/class/attribute_accessors'
require 'active_support/core_ext/hash/conversions'
module ActiveModel
module Serializers
module Xml
extend ActiveSupport::Concern
include ActiveModel::Serialization
class Serializer #:nodoc:
class Attribute #:nodoc:
attr_reader :name, :value, :type
def initialize(name, serializable)
@name, @serializable = name, serializable
@type = compute_type
@value = compute_value
end
# There is a significant speed improvement if the value
# does not need to be escaped, as <tt>tag!</tt> escapes all values
# to ensure that valid XML is generated. For known binary
# values, it is at least an order of magnitude faster to
# Base64 encode binary values and directly put them in the
# output XML than to pass the original value or the Base64
# encoded value to the <tt>tag!</tt> method. It definitely makes
# no sense to Base64 encode the value and then give it to
# <tt>tag!</tt>, since that just adds additional overhead.
def needs_encoding?
![ :binary, :date, :datetime, :boolean, :float, :integer ].include?(type)
end
def decorations(include_types = true)
decorations = {}
if type == :binary
decorations[:encoding] = 'base64'
end
if include_types && type != :string
decorations[:type] = type
end
if value.nil?
decorations[:nil] = true
end
decorations
end
protected
def compute_type
value = @serializable.send(name)
type = Hash::XML_TYPE_NAMES[value.class.name]
type ||= :string if value.respond_to?(:to_str)
type ||= :yaml
type
end
def compute_value
value = @serializable.send(name)
if formatter = Hash::XML_FORMATTING[type.to_s]
value ? formatter.call(value) : nil
else
value
end
end
end
class MethodAttribute < Attribute #:nodoc:
protected
def compute_type
Hash::XML_TYPE_NAMES[@serializable.send(name).class.name] || :string
end
end
attr_reader :options
def initialize(serializable, options = nil)
@serializable = serializable
@options = options ? options.dup : {}
@options[:only] = Array.wrap(@options[:only]).map { |n| n.to_s }
@options[:except] = Array.wrap(@options[:except]).map { |n| n.to_s }
end
# To replicate the behavior in ActiveRecord#attributes,
# <tt>:except</tt> takes precedence over <tt>:only</tt>. If <tt>:only</tt> is not set
# for a N level model but is set for the N+1 level models,
# then because <tt>:except</tt> is set to a default value, the second
# level model can have both <tt>:except</tt> and <tt>:only</tt> set. So if
# <tt>:only</tt> is set, always delete <tt>:except</tt>.
def serializable_attribute_names
attribute_names = @serializable.attributes.keys.sort
if options[:only].any?
attribute_names &= options[:only]
elsif options[:except].any?
attribute_names -= options[:except]
end
attribute_names
end
def serializable_attributes
serializable_attribute_names.collect { |name| Attribute.new(name, @serializable) }
end
def serializable_method_attributes
Array(options[:methods]).inject([]) do |methods, name|
methods << MethodAttribute.new(name.to_s, @serializable) if @serializable.respond_to?(name.to_s)
methods
end
end
def serialize
args = [root]
if options[:namespace]
args << {:xmlns => options[:namespace]}
end
if options[:type]
args << {:type => options[:type]}
end
builder.tag!(*args) do
add_attributes
procs = options.delete(:procs)
options[:procs] = procs
add_procs
yield builder if block_given?
end
end
private
def builder
@builder ||= begin
require 'builder' unless defined? ::Builder
options[:indent] ||= 2
builder = options[:builder] ||= ::Builder::XmlMarkup.new(:indent => options[:indent])
unless options[:skip_instruct]
builder.instruct!
options[:skip_instruct] = true
end
builder
end
end
def root
root = (options[:root] || @serializable.class.model_name.singular).to_s
reformat_name(root)
end
def dasherize?
!options.has_key?(:dasherize) || options[:dasherize]
end
def camelize?
options.has_key?(:camelize) && options[:camelize]
end
def reformat_name(name)
name = name.camelize if camelize?
dasherize? ? name.dasherize : name
end
def add_attributes
(serializable_attributes + serializable_method_attributes).each do |attribute|
builder.tag!(
reformat_name(attribute.name),
attribute.value.to_s,
attribute.decorations(!options[:skip_types])
)
end
end
def add_procs
if procs = options.delete(:procs)
[ *procs ].each do |proc|
if proc.arity > 1
proc.call(options, @serializable)
else
proc.call(options)
end
end
end
end
end
def to_xml(options = {}, &block)
Serializer.new(self, options).serialize(&block)
end
def from_xml(xml)
self.attributes = Hash.from_xml(xml).values.first
self
end
end
end
end