Question

I am working with some code I found online:

def person_path(options)
  # This is where the path of the query is constructed.

  path = "/people/"     # For this section of the LinkedIn API
  if id = options.delete(:id)
    path += "id=#{id}"
  elsif url = options.delete(:url)
    path += "url=#{CGI.escape(url)}"
  else
    path += "~"
  end
end 

I am not completely certain what it does. what I am trying to do is have it construct a string something like this: http://api.linkedin.com/v1/people/~:(current-status) which I got from the LinkedIn developer docs here: https://developer.linkedin.com/documents/profile-api

Any thoughts on what I should pass this functions and how exactly it accomplishes what it does?

Thanks!

Answer 1

Whilst it’s not stated what ‘options’ is, it’s extremely common to pass in options to a method as a Hash of key-value pairs in Ruby, so I’d say that options is just that (with 99% certainty). This is the part that’s key to understanding the rest of the code.

I believe that the #delete method on hash is being used in order to pull out the key-value pair and assign the value in one move, whilst taking advantage of the returned object’s “truthiness”.

http://www.ruby-doc.org/core-1.9.3/Hash.html#method-i-delete

And by “truthiness”, I mean that in Ruby, all objects evaluate to ‘true’ except ‘nil’ and ‘false’.

The rest is simple if-else control flow logic that you will have seen in any other language, so I hope this makes sense.