Module: EnumerateBy::Extensions::Serializer

Defined in:
lib/enumerate_by/extensions/serializer.rb

Overview

Adds support for automatically converting enumeration attributes to the value represented by them.

Examples

Suppose the following models are defined:

class Color < ActiveRecord::Base
  enumerate_by :name

  bootstrap(
    {:id => 1, :name => 'red'},
    {:id => 2, :name => 'blue'},
    {:id => 3, :name => 'green'}
  )
end

class Car < ActiveRecord::Base
  belongs_to :color
end

Given the above, the enumerator for the car will be automatically used for serialization instead of the foreign key like so:

car = Car.create(:color => 'red')  # => #<Car id: 1, color_id: 1>
car.to_xml  # => "<car><id type=\"integer\">1</id><color>red</color></car>"
car.to_json # => "{id: 1, color: \"red\"}"

Conversion options

The actual conversion of enumeration associations can be controlled using the following options:

car.to_json                           # => "{id: 1, color: \"red\"}"
car.to_json(:enumerations => false)   # => "{id: 1, color_id: 1}"
car.to_json(:only => [:color_id])     # => "{color_id: 1}"
car.to_json(:only => [:color])        # => "{color: \"red\"}"
car.to_json(:include => :color)       # => "{id: 1, color_id: 1, color: {id: 1, name: \"red\"}}"

As can be seen from above, enumeration attributes can either be treated as pseudo-attributes on the record or its actual association.

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.included(base) ⇒ Object

:nodoc:



45
46
47
48
49
50
 
# File 'lib/enumerate_by/extensions/serializer.rb', line 45

def self.included(base) #:nodoc:
  base.class_eval do
    alias_method_chain :serializable_attribute_names, :enumerations
    alias_method_chain :serializable_record, :enumerations
  end
end

Instance Method Details

#serializable_attribute_names_with_enumerations ⇒ Object

Automatically converted enumeration attributes to their association names so that they appear as attributes



54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
 
# File 'lib/enumerate_by/extensions/serializer.rb', line 54

def serializable_attribute_names_with_enumerations
  attribute_names = serializable_attribute_names_without_enumerations
  
  # Adjust the serializable attributes by converting primary keys for
  # enumeration associations to their association name (where possible)
  if convert_enumerations?
    @only_attributes = Array(options[:only]).map(&:to_s)
    @include_associations = Array(options[:include]).map(&:to_s)
    
    attribute_names.map! {|attribute| enumeration_association_for(attribute) || attribute}
    attribute_names |= @record.class.enumeration_associations.values & @only_attributes
    attribute_names.sort!
    attribute_names -= options[:except].map(&:to_s) unless options[:only]
  end
  
  attribute_names
end

#serializable_record_with_enumerations ⇒ Object

Automatically casts enumerations to their public values



73
74
75
76
77
78
79
80
 
# File 'lib/enumerate_by/extensions/serializer.rb', line 73

def serializable_record_with_enumerations
  returning(serializable_record = serializable_record_without_enumerations) do
    serializable_record.each do |attribute, value|
      # Typecast to enumerator value
      serializable_record[attribute] = value.enumerator if typecast_to_enumerator?(attribute, value)
    end if convert_enumerations?
  end
end