Equivalent to Rack::Utils.build_query that uses %20 (instead of +) for spaces

Question

I am looking for a function that converts a hash into a query string. I know Rack::Utils.build_query but it use + for spaces.

Why does it matter if you use `+` or `%20`? They should be interpreted as the same thing when decoding. — mu is too short, Oct 27 '13 at 22:39
Think of an api endpoint that requires you to compute a signature based on the query string. — powerboy, Oct 27 '13 at 22:50
In that case, wouldn't you need to parse the URL, standardize it (so that `?a=b&c=d` and `?c=d&a=b` really do come out the same), and then put it back together? Then your "put it back together" step would standardize on `+` or `%20` for spaces. — mu is too short, Oct 28 '13 at 00:27

score 0 · Answer 1 · answered Oct 27 '13 at 22:23

build_query makes use of Rack::Utils.escape, which replaces spaces with + characters. You could add a version of build_query that makes use of Rack::Utils.escape_path, e.g.

module Rack::Utils
  def your_build_query(params)
    params.map { |k, v|
      if v.class == Array
        build_query(v.map { |x| [k, x] })
      else
        v.nil? ? escape_path(k) : "#{escape_path(k)}=#{escape_path(v)}"
      end
    }.join("&")
  end
end

But all escape_path(s) does is escape(s).gsub('+', '%20'), so you could just call Rack::Utils.build_query(s).gsub('+', '%20').

It surely works but essentially it does `str.gsub(' ', '+').gsub('+', '%20')` which it is not ideal. — powerboy, Oct 27 '13 at 22:51

score 0 · Answer 2 · edited May 23 '17 at 12:10

0

Have you looked at URI::encode_www_form? It's built into Ruby.

From the documentation:

URI.encode_www_form([["q", "ruby"], ["lang", "en"]])
#=> "q=ruby&lang=en"
URI.encode_www_form("q" => "ruby", "lang" => "en")
#=> "q=ruby&lang=en"
URI.encode_www_form("q" => ["ruby", "perl"], "lang" => "en")
#=> "q=ruby&q=perl&lang=en"
URI.encode_www_form([["q", "ruby"], ["q", "perl"], ["lang", "en"]])
#=> "q=ruby&q=perl&lang=en"

As for the question of using %20 or +, see "When to encode space to plus (+) or %20?".

edited May 23 '17 at 12:10

Community

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answered Oct 28 '13 at 00:12

the Tin Man

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`URI.encode_www_form` is not different from `Rack::Utils.build_query`. "This method doesn’t convert *, -, ., 0-9, A-Z, _, a-z, but does convert SP (ASCII space) to + and converts others to %XX." – powerboy Oct 28 '13 at 01:20

Equivalent to Rack::Utils.build_query that uses %20 (instead of +) for spaces

2 Answers2