CODEWITHSUNDEEP
ruby
João Daniel
João Daniel

Reputation: 8976

Convert keys and values of a hash to string

I need to convert values and keys of a hash to string, in order to correctly prepare it as params for a Net::HTTP.post_form. For instance:

I need to convert

{:x => [1,2,3,4]}

to

{"x"=>"[1, 2, 3, 4]"}

It's important to convert symbols to string and that arrays are surrounded by quotes.

How can I perform it?

Upvotes: 1

Views: 9467

Answers (2)

mdesantis
mdesantis

Reputation: 8507

What about this

Hash[ { :x => [1,2,3,4] }.map { |k, v| [k.to_s, v.to_s] } ]
#=> {"x"=>"[1, 2, 3, 4]"}

Or on Ruby >= 2.1

{ :x => [1,2,3,4] }.map { |k, v| [k.to_s, v.to_s] }.to_h
#=> {"x"=>"[1, 2, 3, 4]"}

Or on Ruby >= 2.6

{ :x => [1,2,3,4] }.to_h { |k, v| [k.to_s, v.to_s] }
#=> {"x"=>"[1, 2, 3, 4]"}

Upvotes: 11

the Tin Man
the Tin Man

Reputation: 160553

Don't reinvent a well established wheel. Instead Ruby's URI is a good tool to use:

require 'uri'

uri = URI.parse('http://www.example.com')
uri.query = URI.encode_www_form( {:x => [1,2,3,4]} )
uri.to_s # => "http://www.example.com?x=1&x=2&x=3&x=4"

If you want just the query values:

query = URI.encode_www_form( {:x => [1,2,3,4]} ) # => "x=1&x=2&x=3&x=4"

It really sounds like you are reinventing wheels if you are going to send that through Net::HTTP. Serializing a hash to {"x"=>"[1, 2, 3, 4]"} will limit your code to working with only your code. Using JSON, YAML or XML would make your life easier and your code more portable.

JSON makes it easy to move a hash from machine to machine, between languages like Ruby/Python/Java/Perl, whether it is a browser to a server, or client to server:

require 'json'
hash = {:x => [1,2,3,4]}

hash.to_json
=> "{\"x\":[1,2,3,4]}"

JSON[hash.to_json]
=> {
    "x" => [
        [0] 1,
        [1] 2,
        [2] 3,
        [3] 4
    ]
}

That's a round-trip of the hash, to JSON's representation, back to the hash. The intermediate string "{\"x\":[1,2,3,4]}" is easily sent via Net::HTTP.

Upvotes: 4

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