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a469ec787c
Serialization uses only the attributes hash's keys and calls methods that are of the same name as the keys on the serialized object.
142 lines
4.4 KiB
Ruby
142 lines
4.4 KiB
Ruby
require 'active_support/core_ext/hash/except'
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require 'active_support/core_ext/hash/slice'
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require 'active_support/core_ext/array/wrap'
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module ActiveModel
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# == Active Model Serialization
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#
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# Provides a basic serialization to a serializable_hash for your object.
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#
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# A minimal implementation could be:
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#
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# class Person
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#
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# include ActiveModel::Serialization
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#
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# attr_accessor :name
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#
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# def attributes
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# {'name' => nil}
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# end
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#
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# end
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#
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# Which would provide you with:
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#
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# person = Person.new
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# person.serializable_hash # => {"name"=>nil}
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# person.name = "Bob"
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# person.serializable_hash # => {"name"=>"Bob"}
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#
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# You need to declare an attributes hash which contains the attributes
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# you want to serialize. When called, serializable hash will use
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# instance methods that match the name of the attributes hash's keys.
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# In order to override this behavior, take a look at the private
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# method read_attribute_for_serialization.
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#
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# Most of the time though, you will want to include the JSON or XML
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# serializations. Both of these modules automatically include the
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# ActiveModel::Serialization module, so there is no need to explicitly
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# include it.
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#
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# So a minimal implementation including XML and JSON would be:
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#
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# class Person
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#
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# include ActiveModel::Serializers::JSON
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# include ActiveModel::Serializers::Xml
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#
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# attr_accessor :name
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#
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# def attributes
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# {'name' => name}
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# end
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#
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# end
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#
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# Which would provide you with:
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#
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# person = Person.new
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# person.serializable_hash # => {"name"=>nil}
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# person.as_json # => {"name"=>nil}
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# person.to_json # => "{\"name\":null}"
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# person.to_xml # => "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<serial-person...
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#
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# person.name = "Bob"
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# person.serializable_hash # => {"name"=>"Bob"}
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# person.as_json # => {"name"=>"Bob"}
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# person.to_json # => "{\"name\":\"Bob\"}"
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# person.to_xml # => "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<serial-person...
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#
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# Valid options are <tt>:only</tt>, <tt>:except</tt> and <tt>:methods</tt> .
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module Serialization
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def serializable_hash(options = nil)
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options ||= {}
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attribute_names = attributes.keys.sort
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if only = options[:only]
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attribute_names &= Array(only).map(&:to_s)
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elsif except = options[:except]
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attribute_names -= Array(except).map(&:to_s)
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end
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hash = {}
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attribute_names.each { |n| hash[n] = read_attribute_for_serialization(n) }
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method_names = Array(options[:methods]).select { |n| respond_to?(n) }
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method_names.each { |n| hash[n] = send(n) }
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serializable_add_includes(options) do |association, records, opts|
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hash[association] = if records.is_a?(Enumerable)
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records.map { |a| a.serializable_hash(opts) }
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else
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records.serializable_hash(opts)
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end
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end
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hash
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end
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private
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# Hook method defining how an attribute value should be retrieved for
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# serialization. By default this is assumed to be an instance named after
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# the attribute. Override this method in subclasses should you need to
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# retrieve the value for a given attribute differently:
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#
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# class MyClass
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# include ActiveModel::Validations
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#
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# def initialize(data = {})
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# @data = data
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# end
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#
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# def read_attribute_for_serialization(key)
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# @data[key]
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# end
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# end
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#
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alias :read_attribute_for_serialization :send
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# Add associations specified via the <tt>:include</tt> option.
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#
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# Expects a block that takes as arguments:
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# +association+ - name of the association
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# +records+ - the association record(s) to be serialized
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# +opts+ - options for the association records
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def serializable_add_includes(options = {}) #:nodoc:
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return unless include = options[:include]
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unless include.is_a?(Hash)
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include = Hash[Array.wrap(include).map { |n| n.is_a?(Hash) ? n.to_a.first : [n, {}] }]
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end
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include.each do |association, opts|
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if records = send(association)
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yield association, records, opts
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end
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end
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end
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end
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end
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