class HTTP::Headers
Constants
- ACCEPT
Content-Types that are acceptable for 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_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 169 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 22 def initialize @pile = [] end
Public Instance Methods
Compares headers to another Headers or Array of key/value pairs
@return [Boolean]
# File lib/http/headers.rb, line 110 def ==(other) return false unless other.respond_to? :to_a @pile == 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 68 def [](name) values = get(name) case values.count when 0 then nil when 1 then values.first else values end end
Appends header.
@param [#to_s] name header name @param [Array<#to_s>, to_s] value header value(s) to be appended @return [void]
# File lib/http/headers.rb, line 50 def add(name, value) name = normalize_header name.to_s Array(value).each { |v| @pile << [name, v.to_s] } end
Removes header.
@param [#to_s] name header name @return [void]
# File lib/http/headers.rb, line 40 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 119 def each return to_enum(__method__) unless block_given? @pile.each { |arr| yield(arr) } self end
Returns list of header values if any.
@return [Array<String>]
# File lib/http/headers.rb, line 58 def get(name) name = normalize_header name.to_s @pile.select { |k, _| k == name }.map { |_, v| v } end
Properly clones internal key/value storage.
@api private
# File lib/http/headers.rb, line 142 def initialize_copy(orig) super @pile = to_a end
Returns human-readable representation of `self` instance.
@return [String]
# File lib/http/headers.rb, line 96 def inspect "#<#{self.class} #{to_h.inspect}>" end
Returns list of header names.
@return [Array<String>]
# File lib/http/headers.rb, line 103 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 159 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 151 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 30 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 89 def to_a @pile.map { |pair| pair.map(&:dup) } end
Returns Rack-compatible headers Hash
@return [Hash]
# File lib/http/headers.rb, line 81 def to_h Hash[keys.map { |k| [k, self[k]] }] end
Private Instance Methods
Transforms `name` to canonical HTTP header capitalization
@param [String] name @raise [InvalidHeaderNameError] if normalized name does not
match {HEADER_NAME_RE}
@return [String] canonical HTTP header name
# File lib/http/headers.rb, line 194 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 InvalidHeaderNameError, "Invalid HTTP header field name: #{name.inspect}" end