Question

I am using Ruby on Rails 3 and I would like to handle properly web service responses finding a compromise between performance and utility\maneuverability.

I have to decide what type of response my web service must return back to the web client application. I am using JSON for trasmitting data and I would know if it is better to use hashes (for these I have to do extra work) or arrays.

For example I have this response:

[
  {
    "accounts" => {
      [
        "account" => {
          "id"   => 45, 
          "name" => "Test_name45", 
          "..."  => ..."
        }
        "account" => {
          "id"   => 60, 
          "name" => "Test_name60", 
          "..."  => ..."
        }
       ]
     }
   }, 
   {
     "other"  => {
       "sub_other" => {...}
     }
   }
]

I would like to use something like (no array in “accounts”, from “account” to “id”)

  {
    "accounts" => {
      "45" => { 
        "name" => "Test_name45", 
        "..."  => ..."
      }
      "60" => {
        "name" => "Test_name60", 
        "..."  => ..."
      }
   }, 
   {
     "other"  => {
       "sub_other" => {...}
     }
   }

but the latter means more work for the web service…

How to make that? Any advice?

Answer 1

I would use whichever data structure makes sense. If you have a list of things then use an array where each element is a thing. I would probably simplify your data structure to something like this:

{
  "accounts": [
    {
      "id":   45, 
      "name": "Test_name45", 
      "...":  "..."
    },
    {
      "id":   60, 
      "name": "Test_name60", 
      "...":  "..."
    }
  ],
  "other": {
    "sub_other": {"...": "..."}
  }
}

Now, accounts is just an array of objects–no need to go looking things up by key. In Ruby this translates nicely:

ruby-1.9.2-p136 :001 > data = JSON.parse(json)
 => {"accounts"=>[{"id"=>45, "name"=>"Test_name45", "..."=>"..."}, {"id"=>60, "name"=>"Test_name60", "..."=>"..."}], "other"=>{"sub_other"=>{"..."=>"..."}}}
ruby-1.9.2-p136 :002 > data["accounts"].each { |acct| puts acct["name"] }
Test_name45
Test_name60
 => [{"id"=>45, "name"=>"Test_name45", "..."=>"..."}, {"id"=>60, "name"=>"Test_name60", "..."=>"..."}]