Extracting a url comprised of a hash in ruby - ruby

Question

I have a query string that looks as follows:
http://localhost:3000/events?appointment_practices%5B10%5D=Injury&appointment_practices%5B18%5D=Immigration&appointment_practices%5B8%5D=Bankruptcy
appointment_practices is actually a hash I inserted into the query string during a redirect:
appointment_practices = practices.reduce({}) do |acc, practice|
acc[practice.id] = practice.class.name
acc
end
redirect_to events_path(appointment_practices: appointment_practices)
Now I want to parse that query string. When I tried to parse it with decode_www_form, it returns an array with a nil element:
[nil]
This is the code that is giving me the nil element:
#http_refer = #_env['HTTP_REFERER']
begin
uri = URI.parse #http_refer
practices = Hash[URI::decode_www_form(uri.query)].values_at('appointment_practices')
puts "practices: #{practices}"
rescue StandardError
end
I am trying to extract the hash. For example, in appointment_practices%5B10%5D=Injury, the id is 10 and the practice is Injury.
What other options do I have besides regex?

Answer 1

You can use Rack::Utils.parse_nested_query:
require 'uri'
require 'rack'
uri = URI.parse('http://localhost:3000/events?appointment_practices%5B10%5D=Injury&appointment_practices%5B18%5D=Immigration&appointment_practices%5B8%5D=Bankruptcy')
Rack::Utils.parse_nested_query(uri.query)
#=> {"appointment_practices"=>{"10"=>"Injury", "18"=>"Immigration", "8"=>"Bankruptcy"}}