module Net::HTTPHeader

The HTTPHeader module defines methods for reading and writing HTTP headers.

It is used as a mixin by other classes, to provide hash-like access to HTTP header values. Unlike raw hash access, HTTPHeader provides access via case-insensitive keys. It also provides methods for accessing commonly-used HTTP header values in more convenient formats.

Public Instance Methods

[](key) click to toggle source

Returns the header field corresponding to the case-insensitive key. For example, a key of “Content-Type” might return “text/html”

# File lib/net/http/header.rb, line 37
def [](key)
  a = @header[key.downcase] or return nil
  a.join(', ')
end

[]=(key, val) click to toggle source

Sets the header field corresponding to the case-insensitive key.

# File lib/net/http/header.rb, line 43
def []=(key, val)
  unless val
    @header.delete key.downcase
    return val
  end
  set_field(key, val)
end

add_field(key, val) click to toggle source

Ruby 1.8.3

Adds a value to a named header field, instead of replacing its value. Second argument val must be a String. See also []=, [] and get_fields.

request.add_field 'X-My-Header', 'a'
p request['X-My-Header']              #=> "a"
p request.get_fields('X-My-Header')   #=> ["a"]
request.add_field 'X-My-Header', 'b'
p request['X-My-Header']              #=> "a, b"
p request.get_fields('X-My-Header')   #=> ["a", "b"]
request.add_field 'X-My-Header', 'c'
p request['X-My-Header']              #=> "a, b, c"
p request.get_fields('X-My-Header')   #=> ["a", "b", "c"]

# File lib/net/http/header.rb, line 66
def add_field(key, val)
  if @header.key?(key.downcase)
    append_field_value(@header[key.downcase], val)
  else
    set_field(key, val)
  end
end

basic_auth(account, password) click to toggle source

Set the Authorization: header for “Basic” authorization.

# File lib/net/http/header.rb, line 465
def basic_auth(account, password)
  @header['authorization'] = [basic_encode(account, password)]
end

canonical_each()

Alias for: each_capitalized

chunked?() click to toggle source

Returns “true” if the “transfer-encoding” header is present and set to “chunked”. This is an HTTP/1.1 feature, allowing the the content to be sent in “chunks” without at the outset stating the entire content length.

# File lib/net/http/header.rb, line 326
def chunked?
  return false unless @header['transfer-encoding']
  field = self['Transfer-Encoding']
  (/(?:\A|[^\-\w])chunked(?![\-\w])/i =~ field) ? true : false
end

connection_close?() click to toggle source

# File lib/net/http/header.rb, line 479
def connection_close?
  token = /(?:\A|,)\s*close\s*(?:\z|,)/i
  @header['connection']&.grep(token) {return true}
  @header['proxy-connection']&.grep(token) {return true}
  false
end

connection_keep_alive?() click to toggle source

# File lib/net/http/header.rb, line 486
def connection_keep_alive?
  token = /(?:\A|,)\s*keep-alive\s*(?:\z|,)/i
  @header['connection']&.grep(token) {return true}
  @header['proxy-connection']&.grep(token) {return true}
  false
end

content_length() click to toggle source

Returns an Integer object which represents the HTTP Content-Length: header field, or nil if that field was not provided.

# File lib/net/http/header.rb, line 307
def content_length
  return nil unless key?('Content-Length')
  len = self['Content-Length'].slice(/\d+/) or
      raise Net::HTTPHeaderSyntaxError, 'wrong Content-Length format'
  len.to_i
end

content_length=(len) click to toggle source

# File lib/net/http/header.rb, line 314
def content_length=(len)
  unless len
    @header.delete 'content-length'
    return nil
  end
  @header['content-length'] = [len.to_i.to_s]
end

content_range() click to toggle source

Returns a Range object which represents the value of the Content-Range: header field. For a partial entity body, this indicates where this fragment fits inside the full entity body, as range of byte offsets.

# File lib/net/http/header.rb, line 336
def content_range
  return nil unless @header['content-range']
  m = %r<bytes\s+(\d+)-(\d+)/(\d+|\*)>i.match(self['Content-Range']) or
      raise Net::HTTPHeaderSyntaxError, 'wrong Content-Range format'
  m[1].to_i .. m[2].to_i
end

content_type() click to toggle source

Returns a content type string such as “text/html”. This method returns nil if Content-Type: header field does not exist.

# File lib/net/http/header.rb, line 351
def content_type
  return nil unless main_type()
  if sub_type()
  then "#{main_type()}/#{sub_type()}"
  else main_type()
  end
end

content_type=(type, params = {})

Alias for: set_content_type

delete(key) click to toggle source

Removes a header field, specified by case-insensitive key.

# File lib/net/http/header.rb, line 183
def delete(key)
  @header.delete(key.downcase)
end

each()

Alias for: each_header

each_capitalized() { |capitalize(k), join(', ')| ... } click to toggle source

As for each_header, except the keys are provided in capitalized form.

Note that header names are capitalized systematically; capitalization may not match that used by the remote HTTP server in its response.

Returns an enumerator if no block is given.

# File lib/net/http/header.rb, line 208
def each_capitalized
  block_given? or return enum_for(__method__) { @header.size }
  @header.each do |k,v|
    yield capitalize(k), v.join(', ')
  end
end

Also aliased as: canonical_each

each_capitalized_name() { |key| ... } click to toggle source

Iterates through the header names in the header, passing capitalized header names to the code block.

Note that header names are capitalized systematically; capitalization may not match that used by the remote HTTP server in its response.

Returns an enumerator if no block is given.

# File lib/net/http/header.rb, line 164
def each_capitalized_name  #:yield: +key+
  block_given? or return enum_for(__method__) { @header.size }
  @header.each_key do |k|
    yield capitalize(k)
  end
end

each_header() { |key| ... } click to toggle source

Iterates through the header names and values, passing in the name and value to the code block supplied.

Returns an enumerator if no block is given.

Example:

response.header.each_header {|key,value| puts "#{key} = #{value}" }

# File lib/net/http/header.rb, line 136
def each_header   #:yield: +key+, +value+
  block_given? or return enum_for(__method__) { @header.size }
  @header.each do |k,va|
    yield k, va.join(', ')
  end
end

Also aliased as: each

each_key()

Alias for: each_name

each_name() { |key| ... } click to toggle source

Iterates through the header names in the header, passing each header name to the code block.

Returns an enumerator if no block is given.

# File lib/net/http/header.rb, line 149
def each_name(&block)   #:yield: +key+
  block_given? or return enum_for(__method__) { @header.size }
  @header.each_key(&block)
end

Also aliased as: each_key

each_value() { |value| ... } click to toggle source

Iterates through header values, passing each value to the code block.

Returns an enumerator if no block is given.

# File lib/net/http/header.rb, line 175
def each_value   #:yield: +value+
  block_given? or return enum_for(__method__) { @header.size }
  @header.each_value do |va|
    yield va.join(', ')
  end
end

fetch(key, *args) { |key| ... } click to toggle source

Returns the header field corresponding to the case-insensitive key. Returns the default value args, or the result of the block, or raises an IndexError if there's no header field named key See Hash#fetch

# File lib/net/http/header.rb, line 122
def fetch(key, *args, &block)   #:yield: +key+
  a = @header.fetch(key.downcase, *args, &block)
  a.kind_of?(Array) ? a.join(', ') : a
end

form_data=(params, sep = '&')

Alias for: set_form_data

get_fields(key) click to toggle source

Ruby 1.8.3

Returns an array of header field strings corresponding to the case-insensitive key. This method allows you to get duplicated header fields without any processing. See also [].

p response.get_fields('Set-Cookie')
  #=> ["session=al98axx; expires=Fri, 31-Dec-1999 23:58:23",
       "query=rubyscript; expires=Fri, 31-Dec-1999 23:58:23"]
p response['Set-Cookie']
  #=> "session=al98axx; expires=Fri, 31-Dec-1999 23:58:23, query=rubyscript; expires=Fri, 31-Dec-1999 23:58:23"

# File lib/net/http/header.rb, line 113
def get_fields(key)
  return nil unless @header[key.downcase]
  @header[key.downcase].dup
end

initialize_http_header(initheader) click to toggle source

# File lib/net/http/header.rb, line 12
def initialize_http_header(initheader)
  @header = {}
  return unless initheader
  initheader.each do |key, value|
    warn "net/http: duplicated HTTP header: #{key}", uplevel: 1 if key?(key) and $VERBOSE
    if value.nil?
      warn "net/http: nil HTTP header: #{key}", uplevel: 1 if $VERBOSE
    else
      value = value.strip # raise error for invalid byte sequences
      if value.count("\r\n") > 0
        raise ArgumentError, 'header field value cannot include CR/LF'
      end
      @header[key.downcase] = [value]
    end
  end
end

key?(key) click to toggle source

true if key header exists.

# File lib/net/http/header.rb, line 188
def key?(key)
  @header.key?(key.downcase)
end

main_type() click to toggle source

Returns a content type string such as “text”. This method returns nil if Content-Type: header field does not exist.

# File lib/net/http/header.rb, line 361
def main_type
  return nil unless @header['content-type']
  self['Content-Type'].split(';').first.to_s.split('/')[0].to_s.strip
end

proxy_basic_auth(account, password) click to toggle source

Set Proxy-Authorization: header for “Basic” authorization.

# File lib/net/http/header.rb, line 470
def proxy_basic_auth(account, password)
  @header['proxy-authorization'] = [basic_encode(account, password)]
end

range() click to toggle source

Returns an Array of Range objects which represent the Range: HTTP header field, or nil if there is no such header.

# File lib/net/http/header.rb, line 224
def range
  return nil unless @header['range']

  value = self['Range']
  # byte-range-set = *( "," OWS ) ( byte-range-spec / suffix-byte-range-spec )
  #   *( OWS "," [ OWS ( byte-range-spec / suffix-byte-range-spec ) ] )
  # corrected collected ABNF
  # http://tools.ietf.org/html/draft-ietf-httpbis-p5-range-19#section-5.4.1
  # http://tools.ietf.org/html/draft-ietf-httpbis-p5-range-19#appendix-C
  # http://tools.ietf.org/html/draft-ietf-httpbis-p1-messaging-19#section-3.2.5
  unless /\Abytes=((?:,[ \t]*)*(?:\d+-\d*|-\d+)(?:[ \t]*,(?:[ \t]*\d+-\d*|-\d+)?)*)\z/ =~ value
    raise Net::HTTPHeaderSyntaxError, "invalid syntax for byte-ranges-specifier: '#{value}'"
  end

  byte_range_set = $1
  result = byte_range_set.split(/,/).map {|spec|
    m = /(\d+)?\s*-\s*(\d+)?/i.match(spec) or
            raise Net::HTTPHeaderSyntaxError, "invalid byte-range-spec: '#{spec}'"
    d1 = m[1].to_i
    d2 = m[2].to_i
    if m[1] and m[2]
      if d1 > d2
        raise Net::HTTPHeaderSyntaxError, "last-byte-pos MUST greater than or equal to first-byte-pos but '#{spec}'"
      end
      d1..d2
    elsif m[1]
      d1..-1
    elsif m[2]
      -d2..-1
    else
      raise Net::HTTPHeaderSyntaxError, 'range is not specified'
    end
  }
  # if result.empty?
  # byte-range-set must include at least one byte-range-spec or suffix-byte-range-spec
  # but above regexp already denies it.
  if result.size == 1 && result[0].begin == 0 && result[0].end == -1
    raise Net::HTTPHeaderSyntaxError, 'only one suffix-byte-range-spec with zero suffix-length'
  end
  result
end

range=(r, e = nil)

Alias for: set_range

range_length() click to toggle source

The length of the range represented in Content-Range: header.

# File lib/net/http/header.rb, line 344
def range_length
  r = content_range() or return nil
  r.end - r.begin + 1
end

set_content_type(type, params = {}) click to toggle source

Sets the content type in an HTTP header. The type should be a full HTTP content type, e.g. “text/html”. The params are an optional Hash of parameters to add after the content type, e.g. {'charset' => 'iso-8859-1'}

# File lib/net/http/header.rb, line 394
def set_content_type(type, params = {})
  @header['content-type'] = [type + params.map{|k,v|"; #{k}=#{v}"}.join('')]
end

Also aliased as: content_type=

set_form(params, enctype='application/x-www-form-urlencoded', formopt={}) click to toggle source

Set an HTML form data set. params is the form data set; it is an Array of Arrays or a Hash +enctype is the type to encode the form data set. It is application/x-www-form-urlencoded or multipart/form-data. formopt is an optional hash to specify the detail.

boundary: the boundary of the multipart message
charset: the charset of the message. All names and the values of non-file fields are encoded as the charset.

Each item of params is an array and contains following items:

name: the name of the field
value: the value of the field, it should be a String or a File
opt: an optional hash to specify additional information

Each item is a file field or a normal field. If value is a File object or the opt have a filename key, the item is treated as a file field.

If Transfer-Encoding is set as chunked, this send the request in chunked encoding. Because chunked encoding is HTTP/1.1 feature, you must confirm the server to support HTTP/1.1 before sending it.

Example:

http.set_form([["q", "ruby"], ["lang", "en"]])

See also RFC 2388, RFC 2616, HTML 4.01, and HTML5

# File lib/net/http/header.rb, line 450
def set_form(params, enctype='application/x-www-form-urlencoded', formopt={})
  @body_data = params
  @body = nil
  @body_stream = nil
  @form_option = formopt
  case enctype
  when /\Aapplication\/x-www-form-urlencoded\z/i,
    /\Amultipart\/form-data\z/i
    self.content_type = enctype
  else
    raise ArgumentError, "invalid enctype: #{enctype}"
  end
end

set_form_data(params, sep = '&') click to toggle source

Set header fields and a body from HTML form data. params should be an Array of Arrays or a Hash containing HTML form data. Optional argument sep means data record separator.

Values are URL encoded as necessary and the content-type is set to application/x-www-form-urlencoded

Example:

http.form_data = {"q" => "ruby", "lang" => "en"}
http.form_data = {"q" => ["ruby", "perl"], "lang" => "en"}
http.set_form_data({"q" => "ruby", "lang" => "en"}, ';')

# File lib/net/http/header.rb, line 413
def set_form_data(params, sep = '&')
  query = URI.encode_www_form(params)
  query.gsub!(/&/, sep) if sep != '&'
  self.body = query
  self.content_type = 'application/x-www-form-urlencoded'
end

Also aliased as: form_data=

set_range(r, e = nil) click to toggle source

Sets the HTTP Range: header. Accepts either a Range object as a single argument, or a beginning index and a length from that index. Example:

req.range = (0..1023)
req.set_range 0, 1023

# File lib/net/http/header.rb, line 274
def set_range(r, e = nil)
  unless r
    @header.delete 'range'
    return r
  end
  r = (r...r+e) if e
  case r
  when Numeric
    n = r.to_i
    rangestr = (n > 0 ? "0-#{n-1}" : "-#{-n}")
  when Range
    first = r.first
    last = r.end
    last -= 1 if r.exclude_end?
    if last == -1
      rangestr = (first > 0 ? "#{first}-" : "-#{-first}")
    else
      raise Net::HTTPHeaderSyntaxError, 'range.first is negative' if first < 0
      raise Net::HTTPHeaderSyntaxError, 'range.last is negative' if last < 0
      raise Net::HTTPHeaderSyntaxError, 'must be .first < .last' if first > last
      rangestr = "#{first}-#{last}"
    end
  else
    raise TypeError, 'Range/Integer is required'
  end
  @header['range'] = ["bytes=#{rangestr}"]
  r
end

Also aliased as: range=

sub_type() click to toggle source

Returns a content type string such as “html”. This method returns nil if Content-Type: header field does not exist or sub-type is not given (e.g. “Content-Type: text”).

# File lib/net/http/header.rb, line 369
def sub_type
  return nil unless @header['content-type']
  _, sub = *self['Content-Type'].split(';').first.to_s.split('/')
  return nil unless sub
  sub.strip
end

to_hash() click to toggle source

Returns a Hash consisting of header names and array of values. e.g. {“cache-control” => [“private”],

"content-type" => ["text/html"],
"date" => ["Wed, 22 Jun 2005 22:11:50 GMT"]}

# File lib/net/http/header.rb, line 197
def to_hash
  @header.dup
end

type_params() click to toggle source

Any parameters specified for the content type, returned as a Hash. For example, a header of Content-Type: text/html; charset=EUC-JP would result in #type_params returning {'charset' => 'EUC-JP'}

# File lib/net/http/header.rb, line 379
def type_params
  result = {}
  list = self['Content-Type'].to_s.split(';')
  list.shift
  list.each do |param|
    k, v = *param.split('=', 2)
    result[k.strip] = v.strip
  end
  result
end

Private Instance Methods

append_field_value(ary, val) click to toggle source

# File lib/net/http/header.rb, line 89
        def append_field_value(ary, val)
  case val
  when Enumerable
    val.each{|x| append_field_value(ary, x)}
  else
    val = val.to_s
    if /[\r\n]/n.match?(val.b)
      raise ArgumentError, 'header field value cannot include CR/LF'
    end
    ary.push val
  end
end

basic_encode(account, password) click to toggle source

# File lib/net/http/header.rb, line 474
def basic_encode(account, password)
  'Basic ' + ["#{account}:#{password}"].pack('m0')
end

capitalize(name) click to toggle source

# File lib/net/http/header.rb, line 217
def capitalize(name)
  name.to_s.split(/-/).map {|s| s.capitalize }.join('-')
end

set_field(key, val) click to toggle source

# File lib/net/http/header.rb, line 74
        def set_field(key, val)
  case val
  when Enumerable
    ary = []
    append_field_value(ary, val)
    @header[key.downcase] = ary
  else
    val = val.to_s # for compatibility use to_s instead of to_str
    if val.b.count("\r\n") > 0
      raise ArgumentError, 'header field value cannot include CR/LF'
    end
    @header[key.downcase] = [val]
  end
end