converting ruby struct to yaml - struct

Question

I have a struct in ruby that looks like this:
Struct.new("Device", :brand, :model, :port_id)
#devices = [
Struct::Device.new('Apple', 'iphone5', 3),
Struct::Device.new('Samsung', 'Galaxy S4', 1)
]
Converting this to_yaml gives me this result:
---
- !ruby/struct:Struct::Device
brand: Apple
model: iphone5
port_id: 3
- !ruby/struct:Struct::Device
brand: Samsung
model: Galaxy S4
port_id: 1
However I'm still not sure how to convert my struct back from yaml whenever I need to use it in my code. When I add devices: on top of the yaml code and then try to parse it back to ruby struct from the CONFIG['devices'] variable - I don't get any results.
Any help will be appreciated!

Answer 1

I'm not seeing your problem:
irb(main):001:0> require 'yaml'
=> true
irb(main):002:0> Struct.new("Device", :brand, :model, :port_id)
=> Struct::Device
irb(main):003:0> devices = [
irb(main):004:1* Struct::Device.new('Apple', 'iphone5', 3),
irb(main):005:1* Struct::Device.new('Samsung', 'Galaxy S4', 1)
irb(main):006:1> ]
=> [#<struct Struct::Device brand="Apple", model="iphone5", port_id=3>, #<struct Struct::Device brand="Samsung", model="Galaxy S4", port_id=1>]
irb(main):007:0> y = devices.to_yaml
=> "---\n- !ruby/struct:Struct::Device\n brand: Apple\n model: iphone5\n port_id: 3\n- !ruby/struct:Struct::Device\n brand: Samsung\n model: Galaxy S4\n port_id: 1\n"
irb(main):008:0> obj = YAML::load(y)
=> [#<struct Struct::Device brand="Apple", model="iphone5", port_id=3>, #<struct Struct::Device brand="Samsung", model="Galaxy S4", port_id=1>]
You must make sure that the Struct.new runs before the YAML::load as well as before the .to_yaml. Otherwise Ruby doesn't know how to create the struct from text.
Okay, as I said, you must run the Struct definition before trying to load. Plus you are trying to build a hash, so use that YAML syntax:
config.yml:
---
devices:
- !ruby/struct:Struct::Device
brand: Apple
model: iphone5
port_id: 3
- !ruby/struct:Struct::Device
brand: Samsung
model: Galaxy S4
port_id: 1
And test.rb:
require 'yaml'
Struct.new("Device", :brand, :model, :port_id)
CONFIG = YAML::load_file('./config.yml') unless defined? CONFIG
devices = CONFIG['devices']
puts devices.inspect
Result:
C:\>ruby test.rb
[#<struct Struct::Device brand="Apple", model="iphone5", port_id=3>, #<struct Struct::Device brand="Samsung", model="Galaxy S4", port_id=1>]