How to validate if a string is json in a Rails model

Question

I\'m building a simple app and want to be able to store json strings in a db. I have a table Interface with a column json, and I want my rails model to validate the value of the

Answer 1

The best way is to add a method to the JSON module !

Put this in your config/application.rb :

module JSON
  def self.is_json?(foo)
    begin
      return false unless foo.is_a?(String)
      JSON.parse(foo).all?
    rescue JSON::ParserError
      false
    end 
  end
end

Now you'll be enable to use it anywhere ('controller, model, view,...'), just like this :

puts 'it is json' if JSON.is_json?(something)