如何使用字符串插值访问 Rails 应用程序配置数据

Question

I have my third-party credentials set in the config/application.rb like a key, UUID, and other values.

config.username = "username"
config.uuid = "uuid"
config.yyy = "yyy"

For fetching them, I have to write multiple lines to fetch the data which is

Rails.application.config.key

Rails.application.config.UUID

Rails.application.config.yyy

Instead of using the above, I have defined an array with a set of elements loop through it, and get the config value. But I am not able to get the config value, since fetching through a variable is not allowing. Let me know if any alternative

arr = ["key", "uuid", "vv"]
arr.each do |v|
  # Fetching the config value from application config
  Rails.application.config.v 
  # Or
  Rails.application.config."#{v}"
end

Getting an error saying - undefined method `v' for #Rails::Application::Configuration:0x0000000152e4f360 (or) SyntaxError ((irb):1919: syntax error, unexpected tSTRING_BEG)...ass; Rails.application.config."#{v}"

Answer 1

Another way you may want to approach your problem is by storing your related config in a hash:

config.third_party_stuff = { 
  username: 'username',
  uuid:     'uuid',
  yyy:      'yyy'
}

Then you can do can pull it out all together:

third_party_config = Rails.application.config.third_party_stuff

puts "Hey #{third_party_config[:username]}, your uuid is #{third_party_config[:uuid]}"

If you are storing sensitive information, take a look at rails credentials . You can add your related information under a key in the credentials file and get the advantages above while also keeping your data safe.

Answer 2

Where no other mechanism exists, you can use Object#send or Object#public_send to call a dynamic method name. For example:

Rails.configuration.public_send(v)

If another mechanism exists, like square bracket notation, slice method, or obtaining or converting to a hash, that may be considered preferable. I don't see an obvious one in this case.