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 29
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 35
def []=(key, val)
  unless val
    @header.delete key.downcase
    return val
  end
  @header[key.downcase] = [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 58
def add_field(key, val)
  if @header.key?(key.downcase)
    @header[key.downcase].push val
  else
    @header[key.downcase] = [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 419
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 280
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 433
def connection_close?
  tokens(@header['connection']).include?('close') or
  tokens(@header['proxy-connection']).include?('close')
end

connection_keep_alive?() click to toggle source

# File lib/net/http/header.rb, line 438
def connection_keep_alive?
  tokens(@header['connection']).include?('keep-alive') or
  tokens(@header['proxy-connection']).include?('keep-alive')
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 261
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 268
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 290
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 305
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 139
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.

# File lib/net/http/header.rb, line 162
def each_capitalized
  block_given? or return enum_for(__method__)
  @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.

# File lib/net/http/header.rb, line 122
def each_capitalized_name  #:yield: +key+
  block_given? or return enum_for(__method__)
  @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.

Example:

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

# File lib/net/http/header.rb, line 98
def each_header   #:yield: +key+, +value+
  block_given? or return enum_for(__method__)
  @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.

# File lib/net/http/header.rb, line 109
def each_name(&block)   #:yield: +key+
  block_given? or return enum_for(__method__)
  @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.

# File lib/net/http/header.rb, line 131
def each_value   #:yield: +value+
  block_given? or return enum_for(__method__)
  @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 86
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 77
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: warning: duplicated HTTP header: #{key}" if key?(key) and $VERBOSE
    @header[key.downcase] = [value.strip]
  end
end

key?(key) click to toggle source

true if key header exists.

# File lib/net/http/header.rb, line 144
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 315
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 424
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 178
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 298
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 348
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 a 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. formpot 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 404
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 367
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 228
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 323
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 153
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 333
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

basic_encode(account, password) click to toggle source

# File lib/net/http/header.rb, line 428
def basic_encode(account, password)
  'Basic ' + ["#{account}:#{password}"].pack('m').delete("\r\n")
end

capitalize(name) click to toggle source

# File lib/net/http/header.rb, line 171
def capitalize(name)
  name.split(/-/).map {|s| s.capitalize }.join('-')
end

tokens(vals) click to toggle source

# File lib/net/http/header.rb, line 443
def tokens(vals)
  return [] unless vals
  vals.map {|v| v.split(',') }.flatten\
      .reject {|str| str.strip.empty? }\
      .map {|tok| tok.strip.downcase }
end