How to access multiple key-value in URI

Question

I ran into scenario where I m taking multiple input of same field type to render a form.

To give some context:

GET post_ad_form/?tree_field=brand;brand=bmw&tree_field=country;country=India

I need to return the model for brand "bmw" and the cities for country "India" respectively.

The structure is based on "How to design REST URI for multiple Key-Value params of HTTP GET"

How can I access params['tree_field']?

Possible duplicate of [how to get query string from passed url in ruby on rails](https://stackoverflow.com/questions/7316656/how-to-get-query-string-from-passed-url-in-ruby-on-rails) — Gagan Gami, Jun 19 '17 at 07:13
What is your desired output? Accessing `tree_field` is easy. What do you want after you access it? — the Tin Man, Jun 19 '17 at 18:32

score 1 · Accepted Answer · answered Jun 19 '17 at 07:09

1

You can combine URI#parse and CGI#parse to fetch params:

require 'cgi'
require 'uri'
url = 'post_ad_form/?tree_field=brand;brand=bmw&tree_field=country;country=India'
queries = CGI.parse(URI.parse(url).query)
#=> {"tree_field"=>["brand", "country"], "brand"=>["bmw"], "country"=>["India"]}
queries['tree_field'] #=> ["brand", "country"]

However, if you just have the params in a String then you can just use CGI#parse:

params = 'tree_field=brand;brand=bmw&tree_field=country;country=India'
CGI.parse(params)
#=> {"tree_field"=>["brand", "country"], "brand"=>["bmw"], "country"=>["India"]}

answered Jun 19 '17 at 07:09

Surya

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Thanks @surya. I m using sinatra gem. Well this works fine but to the project i m working i m not ment to use `CGI`. – Arun G Jun 19 '17 at 09:05
fyi: cgi and uri are standard libraries in Ruby. – Surya Jun 19 '17 at 09:09
thanks, that I know. I m not allowed to use cgi gem is what i mean. – Arun G Jun 19 '17 at 09:15
If you can't use the CGI gem then why select this as the answer? – the Tin Man Jun 19 '17 at 18:31

the Tin Man · Answer 2 · 2017-06-19T18:49:11.793

Your question isn't clear, but maybe this will help:

require 'uri'

uri = URI.parse('http://somehost.com/post_ad_form/?tree_field=brand;brand=bmw&tree_field=country;country=India')
query = URI.decode_www_form(uri.query).map{ |a| a.last[/;(.+)$/, 1].split('=') }.to_h # => {"brand"=>"bmw", "country"=>"India"}

which breaks down to:

query = URI.decode_www_form(uri.query)       # => [["tree_field", "brand;brand=bmw"], ["tree_field", "country;country=India"]]
  .map{ |a| a.last[/;(.+)$/, 1].split('=') } # => [["brand", "bmw"], ["country", "India"]]
  .to_h                                      # => {"brand"=>"bmw", "country"=>"India"}

How to access multiple key-value in URI

2 Answers2