CODEWITHSUNDEEP
rubyrack
von spotz
von spotz

Reputation: 905

Correct use of the Rack::Response-Object in Server-Answer

i have a question on how to make proper of use the Rack::Response-Object in a server-response.

In line 711 the method Rack::Lint#each (https://github.com/rack/rack/blob/master/lib/rack/lint.rb#L711) asserts among others that part.kind_of? String such that assert("Body yielded non-string value #{part.inspect}")

The most basic response is a triplet like

[status, headers, body]

I got an error message, when I put the Rack::Response-Object in the triplet like that:

[status, headers, rs]

where rs is the Response-Object.

I got it to work with

[status, headers, st.body]

however, as it then passes the above-mentioned assertion !

My question is only if this makes correct use of Rack::Response, or if not, what are then the proper ways of using it in a Server-Response.

Thank you very much

Upvotes: 1

Views: 2377

Answers (1)

Anthony
Anthony

Reputation: 15967

Rack::Response is simply an interface that is new'd up with 3 arguments, the body, the status code and the headers.

The body argument can either respond to #to_str or it must implement #each and whatever is yielded to #each must respond to #to_s.

So as a straightforward answer consider this to be valid:

response = Rack::Response.new(
  ['a','series', 'of', 'strings'],
  200,
  { 'Content-Type' => 'application/json' }
)

This is valid as well

response = Rack::Response.new(
  '{}',
  200,
  { 'Content-Type' => 'application/json' }
)

Or if you have a custom class that say is proxying a response from an API, this would also suffice:

class ApiClient
  def initialize
    @response = get_something
  end

  def each
    @response.chars.each { |el| yield el }
  end

  private

  def get_something
    "a string of responses"
  end
end

response = Rack::Response.new(
  ApiClient.new,
  200,
  { 'Content-Type' => 'application/json' }
)

When you're ready to return your response object back to the caller, you simply called #finish on your Rack::Response instance. This is also aliased as #to_a and #to_ary.

Upvotes: 3

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