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 61

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

  unless headers.is_a?(Hash)
    warn "Providing non-hash headers to Rack::Response is deprecated and will be removed in Rack 3.1", uplevel: 1
  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
    @length = 0
  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 = 0
  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 101

def chunked?
  CHUNKED == get_header(TRANSFER_ENCODING)
end

#close ⇒ Object 


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# File 'lib/rack/response.rb', line 151

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 171

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 131

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 155

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 113

def finish(&block)
  if no_entity_body?
    delete_header CONTENT_TYPE
    delete_header CONTENT_LENGTH
    close
    return [@status, @headers, []]
  else
    if block_given?
      @block = block
      return [@status, @headers, self]
    else
      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 163

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 159

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

#header ⇒ Object

Deprecated, use headers instead.


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# File 'lib/rack/response.rb', line 35

def header
  warn 'Rack::Response#header is deprecated and will be removed in Rack 3.1', uplevel: 1

  headers
end

#no_entity_body? ⇒ Boolean

Returns:

  • (Boolean) 

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# File 'lib/rack/response.rb', line 105

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 96

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 167

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

#write(chunk) ⇒ Object

Append to body and update content-length.

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


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# File 'lib/rack/response.rb', line 145

def write(chunk)
  buffered_body!

  @writer.call(chunk.to_s)
end