Class: HTTP::Headers

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Includes:
Enumerable
Defined in:
lib/http/headers.rb,
lib/http/headers/known.rb,
lib/http/headers/mixin.rb

Overview

HTTP Headers container.

Defined Under Namespace

Modules: Mixin

Constant Summary collapse

CANONICAL_HEADER =

Matches HTTP header names when in "Canonical-Http-Format"

/^[A-Z][a-z]*(-[A-Z][a-z]*)*$/
HEADER_NAME_RE =

Matches valid header field name according to RFC.

See Also:

/^[A-Za-z0-9!#\$%&'*+\-.^_`|~]+$/
ACCEPT =

Content-Types that are acceptable for the response.

"Accept".freeze
AGE =

The age the object has been in a proxy cache in seconds.

"Age".freeze
AUTHORIZATION =

Authentication credentials for HTTP authentication.

"Authorization".freeze
CACHE_CONTROL =

Used to specify directives that must be obeyed by all caching mechanisms along the request-response chain.

"Cache-Control".freeze
"Cookie".freeze
CONNECTION =

Control options for the current connection and list of hop-by-hop request fields.

"Connection".freeze
CONTENT_LENGTH =

The length of the request body in octets (8-bit bytes).

"Content-Length".freeze
CONTENT_TYPE =

The MIME type of the body of the request (used with POST and PUT requests).

"Content-Type".freeze
DATE =

The date and time that the message was sent (in "HTTP-date" format as defined by RFC 7231 Date/Time Formats).

"Date".freeze
ETAG =

An identifier for a specific version of a resource, often a message digest.

"ETag".freeze
EXPIRES =

Gives the date/time after which the response is considered stale (in "HTTP-date" format as defined by RFC 7231).

"Expires".freeze
HOST =

The domain name of the server (for virtual hosting), and the TCP port number on which the server is listening. The port number may be omitted if the port is the standard port for the service requested.

"Host".freeze
IF_MODIFIED_SINCE =

Allows a 304 Not Modified to be returned if content is unchanged.

"If-Modified-Since".freeze
IF_NONE_MATCH =

Allows a 304 Not Modified to be returned if content is unchanged.

"If-None-Match".freeze
LAST_MODIFIED =

The last modified date for the requested object (in "HTTP-date" format as defined by RFC 7231).

"Last-Modified".freeze
LOCATION =

Used in redirection, or when a new resource has been created.

"Location".freeze
PROXY_AUTHORIZATION =

Authorization credentials for connecting to a proxy.

"Proxy-Authorization".freeze
"Set-Cookie".freeze
TRANSFER_ENCODING =

The form of encoding used to safely transfer the entity to the user. Currently defined methods are: chunked, compress, deflate, gzip, identity.

"Transfer-Encoding".freeze
USER_AGENT =

The user agent string of the user agent.

"User-Agent".freeze
VARY =

Tells downstream proxies how to match future request headers to decide whether the cached response can be used rather than requesting a fresh one from the origin server.

"Vary".freeze

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Headers

Class constructor.



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# File 'lib/http/headers.rb', line 21

def initialize
  @pile = []
end

Class Method Details

.coerce(object) ⇒ Headers Also known as: []

Coerces given object into Headers.

Parameters:

Returns:

Raises:

  • (Error) —

    if object can't be coerced



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# File 'lib/http/headers.rb', line 171

def coerce(object)
  unless object.is_a? self
    object = case
             when object.respond_to?(:to_hash) then object.to_hash
             when object.respond_to?(:to_h)    then object.to_h
             when object.respond_to?(:to_a)    then object.to_a
             else fail Error, "Can't coerce #{object.inspect} to Headers"
             end
  end

  headers = new
  object.each { |k, v| headers.add k, v }
  headers
end

Instance Method Details

#==(other) ⇒ Boolean

Compares headers to another Headers or Array of key/value pairs

Returns:

  • (Boolean) 


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# File 'lib/http/headers.rb', line 112

def ==(other)
  return false unless other.respond_to? :to_a
  @pile == other.to_a
end

#[](name) ⇒ nil, ...

Smart version of #get.

Returns:

  • (nil) —

    if header was not set

  • (String) —

    if header has exactly one value

  • (Array<String>) —

    if header has more than one value



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# File 'lib/http/headers.rb', line 70

def [](name)
  values = get(name)

  case values.count
  when 0 then nil
  when 1 then values.first
  else        values
  end
end

#add(name, value) ⇒ void Also known as: append

This method returns an undefined value.

Appends header.

Parameters:

  • name (#to_s) —

    header name

  • value (Array<#to_s>, #to_s) —

    header value(s) to be appended



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# File 'lib/http/headers.rb', line 49

def add(name, value)
  name = normalize_header name.to_s
  Array(value).each { |v| @pile << [name, v.to_s] }
end

#delete(name) ⇒ void

This method returns an undefined value.

Removes header.

Parameters:

  • name (#to_s) —

    header name



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# File 'lib/http/headers.rb', line 39

def delete(name)
  name = normalize_header name.to_s
  @pile.delete_if { |k, _| k == name }
end

#each ⇒ Enumerator, Headers

Calls the given block once for each key/value pair in headers container.

Returns:

  • (Enumerator) —

    if no block given

  • (Headers) —

    self-reference



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# File 'lib/http/headers.rb', line 121

def each
  return to_enum(__method__) unless block_given?
  @pile.each { |arr| yield(arr) }
  self
end

#empty? ⇒ Boolean

Returns true if self has no key/value pairs

Returns:

  • (Boolean) 


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# File 'lib/http/headers.rb', line 131

def_delegator :@pile, :empty?

#get(name) ⇒ Array<String>

Returns list of header values if any.

Returns:

  • (Array<String>) 


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# File 'lib/http/headers.rb', line 60

def get(name)
  name = normalize_header name.to_s
  @pile.select { |k, _| k == name }.map { |_, v| v }
end

#hash ⇒ Fixnum

Compute a hash-code for this headers container. Two conatiners with the same content will have the same hash code.

Returns:

  • (Fixnum)

See Also:



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# File 'lib/http/headers.rb', line 139

def_delegator :@pile, :hash

#initialize_copy(orig) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Properly clones internal key/value storage.



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# File 'lib/http/headers.rb', line 144

def initialize_copy(orig)
  super
  @pile = to_a
end

#inspect ⇒ String

Returns human-readable representation of self instance.

Returns:

  • (String) 


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# File 'lib/http/headers.rb', line 98

def inspect
  "#<#{self.class} #{to_h.inspect}>"
end

#keys ⇒ Array<String>

Returns list of header names.

Returns:

  • (Array<String>) 


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# File 'lib/http/headers.rb', line 105

def keys
  @pile.map { |k, _| k }.uniq
end

#merge(other) ⇒ Headers

Returns new instance with other headers merged in.

Returns:

See Also:



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# File 'lib/http/headers.rb', line 161

def merge(other)
  dup.tap { |dupped| dupped.merge! other }
end

#merge!(other) ⇒ void

This method returns an undefined value.

Merges other headers into self.

See Also:



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# File 'lib/http/headers.rb', line 153

def merge!(other)
  self.class.coerce(other).to_h.each { |name, values| set name, values }
end

#set(name, value) ⇒ void Also known as: []=

This method returns an undefined value.

Sets header.

Parameters:

  • name (#to_s) —

    header name

  • value (Array<#to_s>, #to_s) —

    header value(s) to be appended



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# File 'lib/http/headers.rb', line 29

def set(name, value)
  delete(name)
  add(name, value)
end

#to_a ⇒ Array<[String, String]>

Returns headers key/value pairs.

Returns:

  • (Array<[String, String]>) 


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# File 'lib/http/headers.rb', line 91

def to_a
  @pile.map { |pair| pair.map(&:dup) }
end

#to_h ⇒ Hash Also known as: to_hash

Returns Rack-compatible headers Hash

Returns:

  • (Hash) 


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# File 'lib/http/headers.rb', line 83

def to_h
  Hash[keys.map { |k| [k, self[k]] }]
end