Class: Rack::Response

Inherits:
Object
  • Object
show all
Includes:
Helpers
Defined in:
lib/rack/response.rb

Overview

Rack::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 Response#write to iteratively generate your response, but note that this is buffered by Rack::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 Response#finish.

Direct Known Subclasses

MockResponse

Defined Under Namespace

Modules: Helpers Classes: Raw

Constant Summary collapse

CHUNKED = 
'chunked'
STATUS_WITH_NO_ENTITY_BODY = 
Utils::STATUS_WITH_NO_ENTITY_BODY

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Helpers

#accepted?, #add_header, #bad_request?, #cache!, #cache_control, #cache_control=, #client_error?, #content_length, #content_type, #content_type=, #created?, #delete_cookie, #do_not_cache!, #etag, #etag=, #forbidden?, #include?, #informational?, #invalid?, #location, #location=, #media_type, #media_type_params, #method_not_allowed?, #moved_permanently?, #no_content?, #not_acceptable?, #not_found?, #ok?, #precondition_failed?, #redirect?, #redirection?, #request_timeout?, #server_error?, #set_cookie, #set_cookie_header, #set_cookie_header=, #successful?, #unauthorized?, #unprocessable?

Constructor Details

#initialize(body = nil, status = 200, headers = {}) {|_self| ... } ⇒ Response

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:



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# 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

Instance Attribute Details

#body ⇒ Object

Returns the value of attribute body.



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

def body
  @body
end

#headers ⇒ Object (readonly)

Returns the value of attribute headers.



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

def headers
  @headers
end

#length ⇒ Object

Returns the value of attribute length.



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

def length
  @length
end

#status ⇒ Object

Returns the value of attribute status.



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

def status
  @status
end

Class Method Details

.[](status, headers, body) ⇒ Object 



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

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

Instance Method Details

#chunked? ⇒ Boolean

Returns:

  • (Boolean) 


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

def chunked?
  CHUNKED == get_header(TRANSFER_ENCODING)
end

#close ⇒ Object 



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

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

#delete_header(key) ⇒ Object

Raises:

  • (ArgumentError) 


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

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

#each(&callback) ⇒ Object 



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

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

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

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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

def empty?
  @block == nil && @body.empty?
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]`



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# 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) ⇒ Object Also known as: []

Raises:

  • (ArgumentError) 


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# 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

Returns:

  • (Boolean)

Raises:

  • (ArgumentError) 


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

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

#no_entity_body? ⇒ Boolean

Returns:

  • (Boolean) 


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# 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

#redirect(target, status = 302) ⇒ Object 



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

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

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

Raises:

  • (ArgumentError) 


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

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

#write(chunk) ⇒ Object

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!



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

def write(chunk)
  buffered_body!

  @writer.call(chunk.to_s)
end