class HTTP::Headers
Constants
- ACCEPT
Content-Types that are acceptable for the response.
- ACCEPT_ENCODING
Content-codings that are acceptable in the response.
- AGE
The age the object has been in a proxy cache in seconds.
- AUTHORIZATION
Authentication credentials for
HTTP
authentication.- CACHE_CONTROL
Used to specify directives that must be obeyed by all caching mechanisms along the request-response chain.
- CANONICAL_NAME_RE
Matches
HTTP
header names when in “Canonical-Http-Format”- COMPLIANT_NAME_RE
Matches valid header field name according to RFC. @see tools.ietf.org/html/rfc7230#section-3.2
- CONNECTION
Control options for the current connection and list of hop-by-hop request fields.
- CONTENT_ENCODING
Indicates what additional content codings have been applied to the entity-body.
- CONTENT_LENGTH
The length of the request body in octets (8-bit bytes).
- CONTENT_TYPE
The MIME type of the body of the request (used with POST and PUT requests).
- COOKIE
An
HTTP
cookie previously sent by the server with Set-Cookie.- DATE
The date and time that the message was sent (in “HTTP-date” format as defined by RFC 7231 Date/Time Formats).
- ETAG
An identifier for a specific version of a resource, often a message digest.
- EXPIRES
Gives the date/time after which the response is considered stale (in “HTTP-date” format as defined by RFC 7231).
- 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.
- IF_MODIFIED_SINCE
Allows a 304 Not Modified to be returned if content is unchanged.
- IF_NONE_MATCH
Allows a 304 Not Modified to be returned if content is unchanged.
- LAST_MODIFIED
The last modified date for the requested object (in “HTTP-date” format as defined by RFC 7231).
- LOCATION
Used in redirection, or when a new resource has been created.
- PROXY_AUTHORIZATION
Authorization credentials for connecting to a proxy.
- SET_COOKIE
An
HTTP
cookie.- TRANSFER_ENCODING
The form of encoding used to safely transfer the entity to the user. Currently defined methods are: chunked, compress, deflate, gzip, identity.
- USER_AGENT
The user agent string of the user agent.
- 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.
Public Class Methods
Coerces given ‘object` into Headers
.
@raise [Error] if object can’t be coerced @param [#to_hash, to_h
, to_a
] object @return [Headers]
# File lib/http/headers.rb, line 203 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 raise Error, "Can't coerce #{object.inspect} to Headers" end end headers = new object.each { |k, v| headers.add k, v } headers end
Class constructor.
# File lib/http/headers.rb, line 23 def initialize # The @pile stores each header value using a three element array: # 0 - the normalized header key, used for lookup # 1 - the header key as it will be sent with a request # 2 - the value @pile = [] end
Public Instance Methods
Compares headers to another Headers
or Array of key/value pairs
@return [Boolean]
# File lib/http/headers.rb, line 142 def ==(other) return false unless other.respond_to? :to_a to_a == other.to_a end
Smart version of {#get}.
@return [nil] if header was not set @return [String] if header has exactly one value @return [Array<String>] if header has more than one value
# File lib/http/headers.rb, line 92 def [](name) values = get(name) case values.count when 0 then nil when 1 then values.first else values end end
Appends header.
@param [String, Symbol] name header name. When specified as a string, the
name is sent as-is. When specified as a symbol, the name is converted to a string of capitalized words separated by a dash. Word boundaries are determined by an underscore (`_`) or a dash (`-`). Ex: `:content_type` is sent as `"Content-Type"`, and `"auth_key"` (string) is sent as `"auth_key"`.
@param [Array<#to_s>, to_s] value header value(s) to be appended @return [void]
# File lib/http/headers.rb, line 60 def add(name, value) lookup_name = normalize_header(name.to_s) wire_name = case name when String name when Symbol lookup_name else raise HTTP::HeaderError, "HTTP header must be a String or Symbol: #{name.inspect}" end Array(value).each do |v| @pile << [ lookup_name, wire_name, validate_value(v) ] end end
Removes header.
@param [#to_s] name header name @return [void]
# File lib/http/headers.rb, line 45 def delete(name) name = normalize_header name.to_s @pile.delete_if { |k, _| k == name } end
Calls the given block once for each key/value pair in headers container.
@return [Enumerator] if no block given @return [Headers] self-reference
# File lib/http/headers.rb, line 152 def each return to_enum(__method__) unless block_given? @pile.each { |item| yield(item[1..2]) } self end
Returns list of header values if any.
@return [Array<String>]
# File lib/http/headers.rb, line 82 def get(name) name = normalize_header name.to_s @pile.select { |k, _| k == name }.map { |_, _, v| v } end
Tells whenever header with given ‘name` is set or not.
@return [Boolean]
# File lib/http/headers.rb, line 105 def include?(name) name = normalize_header name.to_s @pile.any? { |k, _| k == name } end
Properly clones internal key/value storage.
@api private
# File lib/http/headers.rb, line 176 def initialize_copy(orig) super @pile = @pile.map(&:dup) end
Returns human-readable representation of ‘self` instance.
@return [String]
# File lib/http/headers.rb, line 128 def inspect "#<#{self.class} #{to_h.inspect}>" end
Returns list of header names.
@return [Array<String>]
# File lib/http/headers.rb, line 135 def keys @pile.map { |_, k, _| k }.uniq end
Returns new instance with ‘other` headers merged in.
@see merge!
@return [Headers]
# File lib/http/headers.rb, line 193 def merge(other) dup.tap { |dupped| dupped.merge! other } end
Merges ‘other` headers into `self`.
@see merge
@return [void]
# File lib/http/headers.rb, line 185 def merge!(other) self.class.coerce(other).to_h.each { |name, values| set name, values } end
Sets header.
@param (see add
) @return [void]
# File lib/http/headers.rb, line 35 def set(name, value) delete(name) add(name, value) end
Returns headers key/value pairs.
@return [Array<[String, String]>]
# File lib/http/headers.rb, line 121 def to_a @pile.map { |item| item[1..2] } end
Returns Rack-compatible headers Hash
@return [Hash]
# File lib/http/headers.rb, line 113 def to_h keys.to_h { |k| [k, self[k]] } end
Private Instance Methods
Transforms ‘name` to canonical HTTP
header capitalization
@param [String] name @raise [HeaderError] if normalized name does not
match {HEADER_NAME_RE}
@return [String] canonical HTTP
header name
# File lib/http/headers.rb, line 228 def normalize_header(name) return name if name =~ CANONICAL_NAME_RE normalized = name.split(/[\-_]/).each(&:capitalize!).join("-") return normalized if normalized =~ COMPLIANT_NAME_RE raise HeaderError, "Invalid HTTP header field name: #{name.inspect}" end
Ensures there is no new line character in the header value
@param [String] value @raise [HeaderError] if value includes new line character @return [String] stringified header value
# File lib/http/headers.rb, line 243 def validate_value(value) v = value.to_s return v unless v.include?("\n") raise HeaderError, "Invalid HTTP header field value: #{v.inspect}" end