Method: ActiveModel::Serializers::JSON#from_json

Defined in:

activemodel/lib/active_model/serializers/json.rb

#from_json(json, include_root = include_root_in_json) ⇒ Object

Sets the model attributes from a JSON string. Returns self.

class Person
  include ActiveModel::Serializers::JSON

  attr_accessor :name, :age, :awesome

  def attributes=(hash)
    hash.each do |key, value|
      send("#{key}=", value)
    end
  end

  def attributes
    instance_values
  end
end

json = { name: 'bob', age: 22, awesome:true }.to_json
person = Person.new
person.from_json(json) # => #<Person:0x007fec5e7a0088 @age=22, @awesome=true, @name="bob">
person.name            # => "bob"
person.age             # => 22
person.awesome         # => true

The default value for include_root is false. You can change it to true if the given JSON string includes a single root node.

json = { person: { name: 'bob', age: 22, awesome:true } }.to_json
person = Person.new
person.from_json(json, true) # => #<Person:0x007fec5e7a0088 @age=22, @awesome=true, @name="bob">
person.name                  # => "bob"
person.age                   # => 22
person.awesome               # => true

# File 'activemodel/lib/active_model/serializers/json.rb', line 146

def from_json(json, include_root = include_root_in_json)
  hash = ActiveSupport::JSON.decode(json)
  hash = hash.values.first if include_root
  self.attributes = hash
  self
end