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Class: Rack::Response

Relationships & Source Files
Namespace Children
Modules:
Helpers
Classes:
Raw
Extension / Inclusion / Inheritance Descendants
Subclasses:
MockResponse
Super Chains via Extension / Inclusion / Inheritance
Instance Chain:
self, Helpers
Inherits: Object
Defined in: lib/rack/response.rb

Overview

Response provides a convenient interface to create a ::Rack response.

It allows setting of headers and cookies, and provides useful defaults (an OK response with empty headers and body).

You can use #write to iteratively generate your response, but note that this is buffered by Response until you call #finish. #finish however can take a block inside which calls to #write are synchronous with the ::Rack response.

Your application’s call should end returning #finish.

Constant Summary

Class Method Summary

Instance Attribute Summary

Helpers - Included

#accepted?, #bad_request?, #cache_control, #cache_control=, #client_error?,
#content_type

Get the content type of the response.
#content_type=

Set the content type of the response.
#created?, #etag, #etag=, #forbidden?, #informational?, #invalid?, #location, #location=, #method_not_allowed?, #moved_permanently?, #no_content?, #not_acceptable?, #not_found?, #ok?, #precondition_failed?, #redirect?, #redirection?, #request_timeout?, #server_error?, #set_cookie_header, #set_cookie_header=, #successful?, #unauthorized?, #unprocessable?

Instance Method Summary

Helpers - Included

#add_header

Add a header that may have multiple values.
#cache!

Specify that the content should be cached.
#content_length, #delete_cookie,
#do_not_cache!

Specifies that the content shouldn’t be cached.
#include?, #media_type, #media_type_params, #set_cookie

Constructor Details

.new(body = nil, status = 200, headers = {}) {|_self| ... } ⇒ Response Also known as: .[]

Initialize the response object with the specified #body, #status and #headers.

If the #body is nil, construct an empty response object with internal buffering.

If the #body responds to to_str, assume it’s a string-like object and construct a buffered response object containing using that string as the initial contents of the buffer.

Otherwise it is expected #body conforms to the normal requirements of a ::Rack response body, typically implementing one of #each (enumerable body) or call (streaming body).

The #status defaults to 200 which is the “OK” HTTP status code. You can provide any other valid status code.

The #headers must be a Hash of key-value header pairs which conform to the ::Rack specification for response headers. The key must be a String instance and the value can be either a String or Array instance.

Yields:

  • (_self)

Yield Parameters:

  • _self (Response) —

    the object that the method was called on

[ GitHub ] 

  


# File 'lib/rack/response.rb', line 54



def initialize(body = nil, status = 200, headers = {})
  @status = status.to_i

  unless headers.is_a?(Hash)
    raise ArgumentError, "Headers must be a Hash!"
  end

  @headers = Headers.new
  # Convert headers input to a plain hash with lowercase keys.
  headers.each do |k, v|
    @headers[k] = v
  end

  @writer = self.method(:append)

  @block = nil

  # Keep track of whether we have expanded the user supplied body.
  if body.nil?
    @body = []
    @buffered = true
    # Body is unspecified - it may be a buffered response, or it may be a HEAD response.
    @length = nil
  elsif body.respond_to?(:to_str)
    @body = [body]
    @buffered = true
    @length = body.to_str.bytesize
  else
    @body = body
    @buffered = nil # undetermined as of yet.
    @length = nil
  end

  yield self if block_given?
end


  







Class Method Details



  

    .[](status, headers, body)  
  

  [ GitHub ]


  

  


# File 'lib/rack/response.rb', line 24



def self.[](status, headers, body)
  self.new(body, status, headers)
end


  







Instance Attribute Details



  

    #body   (rw)
  

  [ GitHub ]


  

  


# File 'lib/rack/response.rb', line 31



attr_accessor :length, :status, :body


  








  

    #chunked?  ⇒ Boolean  (readonly)
  

  [ GitHub ]


  

  


# File 'lib/rack/response.rb', line 95



def chunked?
  CHUNKED == get_header(TRANSFER_ENCODING)
end


  








  

    #empty?  ⇒ Boolean  (readonly)
  

  [ GitHub ]


  

  


# File 'lib/rack/response.rb', line 156



def empty?
  @block == nil && @body.empty?
end


  








  

    #headers   (readonly)
  

  [ GitHub ]


  

  


# File 'lib/rack/response.rb', line 32



attr_reader :headers


  








  

    #length   (rw)
  

  [ GitHub ]


  

  


# File 'lib/rack/response.rb', line 31



attr_accessor :length, :status, :body


  








  

    #no_entity_body?  ⇒ Boolean  (readonly)
  

  [ GitHub ]


  

  


# File 'lib/rack/response.rb', line 99



def no_entity_body?
  # The response body is an enumerable body and it is not allowed to have an entity body.
  @body.respond_to?(:each) && STATUS_WITH_NO_ENTITY_BODY[@status]
end


  








  

    #status   (rw)
  

  [ GitHub ]


  

  


# File 'lib/rack/response.rb', line 31



attr_accessor :length, :status, :body


  







Instance Method Details



  

    #[](key)  
  



  

    

Alias for #get_header.


  



  [ GitHub ]


  

  


# File 'lib/rack/response.rb', line 177



alias :[] :get_header


  








  

    #[]=(key, value)  
  



  

    

Alias for #set_header.


  



  [ GitHub ]


  

  


# File 'lib/rack/response.rb', line 178



alias :[]= :set_header


  








  

    #close  
  

  [ GitHub ]


  

  


# File 'lib/rack/response.rb', line 152



def close
  @body.close if @body.respond_to?(:close)
end


  








  

    #delete_header(key)  
  



  

    
  





  
Raises:


    
  
  • 
    (ArgumentError)
  
    • 





  [ GitHub ]


  

  


# File 'lib/rack/response.rb', line 172



def delete_header(key)
  raise ArgumentError unless key.is_a?(String)
  @headers.delete key
end


  








  

    #each(&callback)  
  

  [ GitHub ]


  

  


# File 'lib/rack/response.rb', line 130



def each(&callback)
  @body.each(&callback)
  @buffered = true

  if @block
    @writer = callback
    @block.call(self)
  end
end


  








  

    #finish(&block)  ⇒ Array 
    Also known as: #to_a
  



  

    

Generate a response array consistent with the requirements of the SPEC. which is suitable to be returned from the middleware #call(env) method.


  





  
Returns:


    
  
  • 
    (Array)
—    
    

    a 3-tuple suitable of [status, headers, body]
    

    
  
    • 





  [ GitHub ]


  

  


# File 'lib/rack/response.rb', line 107



def finish(&block)
  if no_entity_body?
    delete_header CONTENT_TYPE
    delete_header CONTENT_LENGTH
    close
    return [@status, @headers, []]
  else
    if block_given?
      # We don't add the content-length here as the user has provided a block that can #write additional chunks to the body.
      @block = block
      return [@status, @headers, self]
    else
      # If we know the length of the body, set the content-length header... except if we are chunked? which is a legacy special case where the body might already be encoded and thus the actual encoded body length and the content-length are likely to be different.
      if @length && !chunked?
        @headers[CONTENT_LENGTH] = @length.to_s
      end
      return [@status, @headers, @body]
    end
  end
end


  








  

    #get_header(key)  
    Also known as: #[]
  



  

    
  





  
Raises:


    
  
  • 
    (ArgumentError)
  
    • 





  [ GitHub ]


  

  


# File 'lib/rack/response.rb', line 164



def get_header(key)
  raise ArgumentError unless key.is_a?(String)
  @headers[key]
end


  








  

    #has_header?(key)  ⇒ Boolean 
  



  

    
  





  
Raises:


    
  
  • 
    (ArgumentError)
  
    • 





  [ GitHub ]


  

  


# File 'lib/rack/response.rb', line 160



def has_header?(key)
  raise ArgumentError unless key.is_a?(String)
  @headers.key?(key)
end


  








  

    #redirect(target, status = 302)  
  

  [ GitHub ]


  

  


# File 'lib/rack/response.rb', line 90



def redirect(target, status = 302)
  self.status = status
  self.location = target
end


  








  

    #set_header(key, value)  
    Also known as: #[]=
  



  

    
  





  
Raises:


    
  
  • 
    (ArgumentError)
  
    • 





  [ GitHub ]


  

  


# File 'lib/rack/response.rb', line 168



def set_header(key, value)
  raise ArgumentError unless key.is_a?(String)
  @headers[key] = value
end


  








  

    #to_a(&block)  
  



  

    

Alias for #finish.


  



  [ GitHub ]


  

  


# File 'lib/rack/response.rb', line 128



alias to_a finish           # For *response


  








  

    #write(chunk)  
  



  

    

Append a chunk to the response body.



Converts the response into a buffered response if it wasn’t already.



NOTE: Do not mix #write and direct #body access!


  



  [ GitHub ]


  

  


# File 'lib/rack/response.rb', line 146



def write(chunk)
  buffered_body!

  @writer.call(chunk.to_s)
end