Question

I am using Ruby on Rails 3 and I would like to solve an issue with the following code where a web client application receive back some JSON data from a web service application that uses a Rack middleware in order to respond.

In the web client app model I have

response_parsed = JSON.parse(response.body)
if response_parsed["account"]
  ...
else
  return response
end

In the above code the response.body come back from the web service app that uses a Rack middleware to respond to the web client:

accounts = Account.where(:id => ids)
[200, {'Content-Type' => 'application/json'}, accounts.to_json] # That is, response.body = accounts.to_json

Data transmission is ok, but I get the following error

TypeError
can't convert String into Integer

*Application Trace* 
lib/accounts.rb:107:in `[]'

The line 107 corresponds to

if response_parsed["account"]
  ...

Where and what is the problem? How to solve that?

---

If I try to debug the respons.body I get

# Note: this is an array!
"[{\"account\":{\"firstname\":\"Semio\",\"lastname\":\"Iaven\"\"}}]"

Answer 1

If I’m saying something you already realize, forgive me.

It looks like your response is a one-element array with a hash in it as the first element. Because the response is an array, when you use the [] it is expecting a integer representing the index of the item in the array you’d like to access, and that is what the error message means–it expected that you’d tell it the integer value of the item you wanted, but instead you gave it a string.

If you instead do:

response_parsed[0]['account']

It seems like you’d get what you want.