Class: Serializer

Inherits:
Object
  • Object
show all
Defined in:
lib/serializer.rb,
lib/serializer/version.rb

Defined Under Namespace

Classes: Attribute, SerializerError

Constant Summary collapse

VERSION = 
"0.1.0"

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(object, scope: {}) ⇒ Serializer

Returns a new instance of Serializer.



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# File 'lib/serializer.rb', line 19

def initialize(object, scope: {})
  @object = object
  @scope = scope
end

Instance Attribute Details

#object ⇒ Object

Returns the value of attribute object.



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# File 'lib/serializer.rb', line 17

def object
  @object
end

#scope ⇒ Object

Returns the value of attribute scope.



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# File 'lib/serializer.rb', line 17

def scope
  @scope
end

Class Method Details

.attribute(key, condition: nil, from: nil, serializer: nil, **options) ⇒ Object 



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# File 'lib/serializer.rb', line 13

def self.attribute(key, condition: nil, from: nil, serializer: nil, **options)
  attributes.push(Attribute.new(key, condition, from, serializer, options))
end

.attributes ⇒ Object 



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# File 'lib/serializer.rb', line 9

def self.attributes
  @attributes ||= []
end

Instance Method Details

#to_h ⇒ Object

Loops over all attributes and skips if a condition is defined and falsey



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# File 'lib/serializer.rb', line 25

def to_h
  self.class.attributes.each_with_object({}) do |attribute, obj|
    next if attribute.condition && !public_send(attribute.condition)

    extraction_key = attribute.from || attribute.key

    # Fetches a value from an attribute by checking if there's a ..
    # .. static value set, or a ..
    # .. method defined in the serializer, or a ..
    # .. method/attribute defined in the object or ..
    # .. it raises an error
    value = if attribute.options.has_key?(:static_value)
              attribute.options.fetch(:static_value)
            elsif respond_to?(extraction_key)
              public_send(extraction_key)
            elsif object.respond_to?(extraction_key) && attribute.serializer
              value = object.public_send(extraction_key)

              serialize_value(value, attribute.serializer)
            elsif object.respond_to?(extraction_key)
              object.public_send(extraction_key)
            else
              raise SerializerError, "unknown attribute '#{extraction_key}'"
            end

    obj[attribute.key] = value
  end
end

#to_json ⇒ Object 



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# File 'lib/serializer.rb', line 54

def to_json(*)
  Appsignal.instrument('json.serialize', 'Serializer', self.class.to_s) do
    Oj.dump(to_h, mode: :json)
  end
end