为什么这个Rails操作返回一个字符串而不是JSON？

Question

I am accessing one of my Rails actions from the Rails console:

> @consumer = OAuth::Consumer.new(
>   x,
>   x,
>   site: "http://localhost:3000"
> )
> request = @consumer.create_signed_request(:get,"/get_user_info?email=x")
> uri = URI.parse("http://localhost:3000")
> http = Net::HTTP.new(uri.host, uri.port)
> http.request(request).body
=> "{\"first_thing\":\"Nick\",\"second_thing\":\"2012-12-26T11:41:11Z\",\"third_thing\":\"2012-12-26T11:40:03Z\"}"
> http.request(request).body.class
=> String

The action is supposed to be returning a hash in JSON, not a string. Here is the how the action ends:

render json: {
    first_thing: x,
    second_thing: x,
    third_thing: x
}

Why would this be coming through as a string? I'm using Rails 3.2.0 and Ruby 1.9.3.

Answer 1

You will always get a String from an HTTP request. render :json just converts the hash into a JSON String.

You need to do JSON.parse on the String.

Answer 2

It return JSON, because whole HTTP messages are string based. So to get JSON object in console you need call JSON.parse on response body.

JSON.parse(http.request(request).body) # => {
#    first_thing: x,
#    second_thing: x,
#    third_thing: x
#}