module Net::HTTPHeader

The HTTPHeader module provides access to HTTP headers.

The module is included in:

Net::HTTPGenericRequest (and therefore Net::HTTPRequest).
Net::HTTPResponse.

The headers are a hash-like collection of key/value pairs called fields.

Request and Response Fields¶ ↑

Headers may be included in:

A Net::HTTPRequest object: the object’s headers will be sent with the request. Any fields may be defined in the request; see Setters.
A Net::HTTPResponse object: the objects headers are usually those returned from the host. Fields may be retrieved from the object; see Getters and Iterators.

Exactly which fields should be sent or expected depends on the host; see:

About the Examples¶ ↑

Examples here assume that net/http has been required (which also requires uri):

require 'net/http'

Many code examples here use these example websites:

Some examples also assume these variables:

uri = URI('https://jsonplaceholder.typicode.com/')
uri.freeze # Examples may not modify.
hostname = uri.hostname # => "jsonplaceholder.typicode.com"
path = uri.path         # => "/"
port = uri.port         # => 443

So that example requests may be written as:

Net::HTTP.get(uri)
Net::HTTP.get(hostname, '/index.html')
Net::HTTP.start(hostname) do |http|
  http.get('/todos/1')
  http.get('/todos/2')
end

An example that needs a modified URI first duplicates uri, then modifies the duplicate:

_uri = uri.dup
_uri.path = '/todos/1'

Fields¶ ↑

A header field is a key/value pair.

Field Keys¶ ↑

A field key may be:

A string: Key 'Accept' is treated as if it were 'Accept'.downcase; i.e., 'accept'.
A symbol: Key :Accept is treated as if it were :Accept.to_s.downcase; i.e., 'accept'.

Examples:

req = Net::HTTP::Get.new(uri)
req[:accept]  # => "*/*"
req['Accept'] # => "*/*"
req['ACCEPT'] # => "*/*"

req['accept'] = 'text/html'
req[:accept] = 'text/html'
req['ACCEPT'] = 'text/html'

Field Values¶ ↑

A field value may be returned as an array of strings or as a string:

These methods return field values as arrays:
- get_fields: Returns the array value for the given key, or nil if it does not exist.
- to_hash: Returns a hash of all header fields: each key is a field name; its value is the array value for the field.
These methods return field values as string; the string value for a field is equivalent to self[key.downcase.to_s].join(', ')):
- []: Returns the string value for the given key, or nil if it does not exist.
- fetch: Like [], but accepts a default value to be returned if the key does not exist.

The field value may be set:

[]=: Sets the value for the given key; the given value may be a string, a symbol, an array, or a hash.
add_field: Adds a given value to a value for the given key (not overwriting the existing value).
delete: Deletes the field for the given key.

Example field values:

String:

req['Accept'] = 'text/html' # => "text/html"
req['Accept']               # => "text/html"
req.get_fields('Accept')    # => ["text/html"]

Symbol:

req['Accept'] = :text    # => :text
req['Accept']            # => "text"
req.get_fields('Accept') # => ["text"]

Simple array:

req[:foo] = %w[bar baz bat]
req[:foo]            # => "bar, baz, bat"
req.get_fields(:foo) # => ["bar", "baz", "bat"]

Simple hash:

req[:foo] = {bar: 0, baz: 1, bat: 2}
req[:foo]            # => "bar, 0, baz, 1, bat, 2"
req.get_fields(:foo) # => ["bar", "0", "baz", "1", "bat", "2"]

Nested:

req[:foo] = [%w[bar baz], {bat: 0, bam: 1}]
req[:foo]            # => "bar, baz, bat, 0, bam, 1"
req.get_fields(:foo) # => ["bar", "baz", "bat", "0", "bam", "1"]

req[:foo] = {bar: %w[baz bat], bam: {bah: 0, bad: 1}}
req[:foo]            # => "bar, baz, bat, bam, bah, 0, bad, 1"
req.get_fields(:foo) # => ["bar", "baz", "bat", "bam", "bah", "0", "bad", "1"]

Convenience Methods¶ ↑

Various convenience methods retrieve values, set values, query values, set form values, or iterate over fields.

Setters¶ ↑

Method []= can set any field, but does little to validate the new value; some of the other setter methods provide some validation:

[]=: Sets the string or array value for the given key.
add_field: Creates or adds to the array value for the given key.
basic_auth: Sets the string authorization header for 'Authorization'.
content_length=: Sets the integer length for field 'Content-Length.
content_type=: Sets the string value for field 'Content-Type'.
proxy_basic_auth: Sets the string authorization header for 'Proxy-Authorization'.
set_range: Sets the value for field 'Range'.

Form Setters¶ ↑

set_form: Sets an HTML form data set.
set_form_data: Sets header fields and a body from HTML form data.

Getters¶ ↑

Method [] can retrieve the value of any field that exists, but always as a string; some of the other getter methods return something different from the simple string value:

[]: Returns the string field value for the given key.
content_length: Returns the integer value of field 'Content-Length'.
content_range: Returns the Range value of field 'Content-Range'.
content_type: Returns the string value of field 'Content-Type'.
fetch: Returns the string field value for the given key.
get_fields: Returns the array field value for the given key.
main_type: Returns first part of the string value of field 'Content-Type'.
sub_type: Returns second part of the string value of field 'Content-Type'.
range: Returns an array of Range objects of field 'Range', or nil.
range_length: Returns the integer length of the range given in field 'Content-Range'.
type_params: Returns the string parameters for 'Content-Type'.

Queries¶ ↑

chunked?: Returns whether field 'Transfer-Encoding' is set to 'chunked'.
connection_close?: Returns whether field 'Connection' is set to 'close'.
connection_keep_alive?: Returns whether field 'Connection' is set to 'keep-alive'.
key?: Returns whether a given key exists.

Iterators¶ ↑

each_capitalized: Passes each field capitalized-name/value pair to the block.
each_capitalized_name: Passes each capitalized field name to the block.
each_header: Passes each field name/value pair to the block.
each_name: Passes each field name to the block.
each_value: Passes each string field value to the block.

Constants

MAX_FIELD_LENGTH
MAX_KEY_LENGTH

Public Instance Methods

[] (key)

Returns the string field value for the case-insensitive field key, or nil if there is no such key; see Fields:

res = Net::HTTP.get_response(hostname, '/todos/1')
res['Connection'] # => "keep-alive"
res['Nosuch']     # => nil

Note that some field values may be retrieved via convenience methods; see Getters.

# File lib/net/http/header.rb, line 224
def [](key)
  a = @header[key.downcase.to_s] or return nil
  a.join(', ')
end

[]= (key, val)

Sets the value for the case-insensitive key to val, overwriting the previous value if the field exists; see Fields:

req = Net::HTTP::Get.new(uri)
req['Accept'] # => "*/*"
req['Accept'] = 'text/html'
req['Accept'] # => "text/html"

Note that some field values may be set via convenience methods; see Setters.

# File lib/net/http/header.rb, line 240
def []=(key, val)
  unless val
    @header.delete key.downcase.to_s
    return val
  end
  set_field(key, val)
end

add_field (key, val)

Adds value val to the value array for field key if the field exists; creates the field with the given key and val if it does not exist. see Fields:

req = Net::HTTP::Get.new(uri)
req.add_field('Foo', 'bar')
req['Foo']            # => "bar"
req.add_field('Foo', 'baz')
req['Foo']            # => "bar, baz"
req.add_field('Foo', %w[baz bam])
req['Foo']            # => "bar, baz, baz, bam"
req.get_fields('Foo') # => ["bar", "baz", "baz", "bam"]

# File lib/net/http/header.rb, line 261
def add_field(key, val)
  stringified_downcased_key = key.downcase.to_s
  if @header.key?(stringified_downcased_key)
    append_field_value(@header[stringified_downcased_key], val)
  else
    set_field(key, val)
  end
end

basic_auth (account, password)

Sets header 'Authorization' using the given account and password strings:

req.basic_auth('my_account', 'my_password')
req['Authorization']
# => "Basic bXlfYWNjb3VudDpteV9wYXNzd29yZA=="

# File lib/net/http/header.rb, line 945
def basic_auth(account, password)
  @header['authorization'] = [basic_encode(account, password)]
end

canonical_each ()

Alias for: each_capitalized

chunked? ()

Returns true if field 'Transfer-Encoding' exists and has value 'chunked', false otherwise; see Transfer-Encoding response header:

res = Net::HTTP.get_response(hostname, '/todos/1')
res['Transfer-Encoding'] # => "chunked"
res.chunked?             # => true

# File lib/net/http/header.rb, line 654
def chunked?
  return false unless @header['transfer-encoding']
  field = self['Transfer-Encoding']
  (/(?:\A|[^\-\w])chunked(?![\-\w])/i =~ field) ? true : false
end

connection_close? ()

Returns whether the HTTP session is to be closed.

# File lib/net/http/header.rb, line 966
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? ()

Returns whether the HTTP session is to be kept alive.

# File lib/net/http/header.rb, line 974
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 ()

Returns the value of field 'Content-Length' as an integer, or nil if there is no such field; see Content-Length request header:

res = Net::HTTP.get_response(hostname, '/nosuch/1')
res.content_length # => 2
res = Net::HTTP.get_response(hostname, '/todos/1')
res.content_length # => nil

# File lib/net/http/header.rb, line 616
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)

Sets the value of field 'Content-Length' to the given numeric; see Content-Length response header:

_uri = uri.dup
hostname = _uri.hostname           # => "jsonplaceholder.typicode.com"
_uri.path = '/posts'               # => "/posts"
req = Net::HTTP::Post.new(_uri)    # => #<Net::HTTP::Post POST>
req.body = '{"title": "foo","body": "bar","userId": 1}'
req.content_length = req.body.size # => 42
req.content_type = 'application/json'
res = Net::HTTP.start(hostname) do |http|
  http.request(req)
end # => #<Net::HTTPCreated 201 Created readbody=true>

# File lib/net/http/header.rb, line 637
def content_length=(len)
  unless len
    @header.delete 'content-length'
    return nil
  end
  @header['content-length'] = [len.to_i.to_s]
end

content_range ()

Returns a Range object representing the value of field 'Content-Range', or nil if no such field exists; see Content-Range response header:

res = Net::HTTP.get_response(hostname, '/todos/1')
res['Content-Range'] # => nil
res['Content-Range'] = 'bytes 0-499/1000'
res['Content-Range'] # => "bytes 0-499/1000"
res.content_range    # => 0..499

# File lib/net/http/header.rb, line 670
def content_range
  return nil unless @header['content-range']
  m = %r<\A\s*(\w+)\s+(\d+)-(\d+)/(\d+|\*)>.match(self['Content-Range']) or
      raise Net::HTTPHeaderSyntaxError, 'wrong Content-Range format'
  return unless m[1] == 'bytes'
  m[2].to_i .. m[3].to_i
end

content_type ()

Returns the media type from the value of field 'Content-Type', or nil if no such field exists; see Content-Type response header:

res = Net::HTTP.get_response(hostname, '/todos/1')
res['content-type'] # => "application/json; charset=utf-8"
res.content_type    # => "application/json"

# File lib/net/http/header.rb, line 701
def content_type
  main = main_type()
  return nil unless main

  sub = sub_type()
  if sub
    "#{main}/#{sub}"
  else
    main
  end
end

content_type= (type, params = {})

Alias for: set_content_type

delete (key)

Removes the header for the given case-insensitive key (see Fields); returns the deleted value, or nil if no such field exists:

req = Net::HTTP::Get.new(uri)
req.delete('Accept') # => ["*/*"]
req.delete('Nosuch') # => nil

# File lib/net/http/header.rb, line 453
def delete(key)
  @header.delete(key.downcase.to_s)
end

each ()

Alias for: each_header

each_capitalized () { |capitalize(k), join(', ')| ... }

Like each_header, but the keys are returned in capitalized form.

Net::HTTPHeader#canonical_each is an alias for Net::HTTPHeader#each_capitalized.

# File lib/net/http/header.rb, line 484
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| ... }

Calls the block with each capitalized field name:

res = Net::HTTP.get_response(hostname, '/todos/1')
res.each_capitalized_name do |key|
  p key if key.start_with?('C')
end

Output:

"Content-Type"
"Connection"
"Cache-Control"
"Cf-Cache-Status"
"Cf-Ray"

The capitalization is system-dependent; see Case Mapping.

Returns an enumerator if no block is given.

# File lib/net/http/header.rb, line 417
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| ... }

Calls the block with each key/value pair:

res = Net::HTTP.get_response(hostname, '/todos/1')
res.each_header do |key, value|
  p [key, value] if key.start_with?('c')
end

Output:

["content-type", "application/json; charset=utf-8"]
["connection", "keep-alive"]
["cache-control", "max-age=43200"]
["cf-cache-status", "HIT"]
["cf-ray", "771d17e9bc542cf5-ORD"]

Returns an enumerator if no block is given.

Net::HTTPHeader#each is an alias for Net::HTTPHeader#each_header.

# File lib/net/http/header.rb, line 364
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| ... }

Calls the block with each field key:

res = Net::HTTP.get_response(hostname, '/todos/1')
res.each_key do |key|
  p key if key.start_with?('c')
end

Output:

"content-type"
"connection"
"cache-control"
"cf-cache-status"
"cf-ray"

Returns an enumerator if no block is given.

Net::HTTPHeader#each_name is an alias for Net::HTTPHeader#each_key.

# File lib/net/http/header.rb, line 391
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| ... }

Calls the block with each string field value:

res = Net::HTTP.get_response(hostname, '/todos/1')
res.each_value do |value|
  p value if value.start_with?('c')
end

Output:

"chunked"
"cf-q-config;dur=6.0000002122251e-06"
"cloudflare"

Returns an enumerator if no block is given.

# File lib/net/http/header.rb, line 438
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, default_val = nil) {|key| ... } → object

fetch(key, default_val = nil) → value or default_val

With a block, returns the string value for key if it exists; otherwise returns the value of the block; ignores the default_val; see Fields:

res = Net::HTTP.get_response(hostname, '/todos/1')

# Field exists; block not called.
res.fetch('Connection') do |value|
  fail 'Cannot happen'
end # => "keep-alive"

# Field does not exist; block called.
res.fetch('Nosuch') do |value|
  value.downcase
end # => "nosuch"

With no block, returns the string value for key if it exists; otherwise, returns default_val if it was given; otherwise raises an exception:

res.fetch('Connection', 'Foo') # => "keep-alive"
res.fetch('Nosuch', 'Foo')     # => "Foo"
res.fetch('Nosuch')            # Raises KeyError.

# File lib/net/http/header.rb, line 341
def fetch(key, *args, &block)   #:yield: +key+
  a = @header.fetch(key.downcase.to_s, *args, &block)
  a.kind_of?(Array) ? a.join(', ') : a
end

form_data= (params, sep = '&')

Alias for: set_form_data

get_fields (key)

Returns the array field value for the given key, or nil if there is no such field; see Fields:

res = Net::HTTP.get_response(hostname, '/todos/1')
res.get_fields('Connection') # => ["keep-alive"]
res.get_fields('Nosuch')     # => nil

# File lib/net/http/header.rb, line 306
def get_fields(key)
  stringified_downcased_key = key.downcase.to_s
  return nil unless @header[stringified_downcased_key]
  @header[stringified_downcased_key].dup
end

key? (key)

Returns true if the field for the case-insensitive key exists, false otherwise:

req = Net::HTTP::Get.new(uri)
req.key?('Accept') # => true
req.key?('Nosuch') # => false

# File lib/net/http/header.rb, line 463
def key?(key)
  @header.key?(key.downcase.to_s)
end

main_type ()

Returns the leading (‘type’) part of the media type from the value of field 'Content-Type', or nil if no such field exists; see Content-Type response header:

res = Net::HTTP.get_response(hostname, '/todos/1')
res['content-type'] # => "application/json; charset=utf-8"
res.main_type       # => "application"

# File lib/net/http/header.rb, line 723
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)

Sets header 'Proxy-Authorization' using the given account and password strings:

req.proxy_basic_auth('my_account', 'my_password')
req['Proxy-Authorization']
# => "Basic bXlfYWNjb3VudDpteV9wYXNzd29yZA=="

# File lib/net/http/header.rb, line 956
def proxy_basic_auth(account, password)
  @header['proxy-authorization'] = [basic_encode(account, password)]
end

range ()

Returns an array of Range objects that represent the value of field 'Range', or nil if there is no such field; see Range request header:

req = Net::HTTP::Get.new(uri)
req['Range'] = 'bytes=0-99,200-299,400-499'
req.range # => [0..99, 200..299, 400..499]
req.delete('Range')
req.range # # => nil

# File lib/net/http/header.rb, line 509
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=

Alias for: set_range

range_length ()

Returns the integer representing length of the value of field 'Content-Range', or nil if no such field exists; see Content-Range response header:

res = Net::HTTP.get_response(hostname, '/todos/1')
res['Content-Range'] # => nil
res['Content-Range'] = 'bytes 0-499/1000'
res.range_length     # => 500

# File lib/net/http/header.rb, line 687
def range_length
  r = content_range() or return nil
  r.end - r.begin + 1
end

set_content_type (type, params = {})

Sets the value of field 'Content-Type'; returns the new value; see Content-Type request header:

req = Net::HTTP::Get.new(uri)
req.set_content_type('application/json') # => ["application/json"]

Net::HTTPHeader#content_type= is an alias for Net::HTTPHeader#set_content_type.

# File lib/net/http/header.rb, line 772
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={})

Stores form data to be used in a POST or PUT request.

The form data given in params consists of zero or more fields; each field is:

A scalar value.
A name/value pair.
An IO stream opened for reading.

Argument params should be an Enumerable (method params.map will be called), and is often an array or hash.

First, we set up a request:

_uri = uri.dup
_uri.path ='/posts'
req = Net::HTTP::Post.new(_uri)

Argument params As an Array

When params is an array, each of its elements is a subarray that defines a field; the subarray may contain:

One string:

req.set_form([['foo'], ['bar'], ['baz']])

Two strings:

req.set_form([%w[foo 0], %w[bar 1], %w[baz 2]])

When argument enctype (see below) is given as 'multipart/form-data':
- A string name and an IO stream opened for reading:
```
require 'stringio'
req.set_form([['file', StringIO.new('Ruby is cool.')]])
```
- A string name, an IO stream opened for reading, and an options hash, which may contain these entries:
  - :filename: The name of the file to use.
  - :content_type: The content type of the uploaded file.
  Example:
```
req.set_form([['file', file, {filename: "other-filename.foo"}]]
```

The various forms may be mixed:

req.set_form(['foo', %w[bar 1], ['file', file]])

Argument params As a Hash

When params is a hash, each of its entries is a name/value pair that defines a field:

The name is a string.
The value may be:
- nil.
- Another string.
- An IO stream opened for reading (only when argument enctype – see below – is given as 'multipart/form-data').

Examples:

# Nil-valued fields.
req.set_form({'foo' => nil, 'bar' => nil, 'baz' => nil})

# String-valued fields.
req.set_form({'foo' => 0, 'bar' => 1, 'baz' => 2})

# IO-valued field.
require 'stringio'
req.set_form({'file' => StringIO.new('Ruby is cool.')})

# Mixture of fields.
req.set_form({'foo' => nil, 'bar' => 1, 'file' => file})

Optional argument enctype specifies the value to be given to field 'Content-Type', and must be one of:

'application/x-www-form-urlencoded' (the default).
'multipart/form-data'; see RFC 7578.

Optional argument formopt is a hash of options (applicable only when argument enctype is 'multipart/form-data') that may include the following entries:

:boundary: The value is the boundary string for the multipart message. If not given, the boundary is a random string. See Boundary.
:charset: Value is the character set for the form submission. Field names and values of non-file fields should be encoded with this charset.

# File lib/net/http/header.rb, line 924
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 = '&')

Sets the request body to a URL-encoded string derived from argument params, and sets request header field 'Content-Type' to 'application/x-www-form-urlencoded'.

The resulting request is suitable for HTTP request POST or PUT.

Argument params must be suitable for use as argument enum to URI.encode_www_form.

With only argument params given, sets the body to a URL-encoded string with the default separator '&':

req = Net::HTTP::Post.new('example.com')

req.set_form_data(q: 'ruby', lang: 'en')
req.body            # => "q=ruby&lang=en"
req['Content-Type'] # => "application/x-www-form-urlencoded"

req.set_form_data([['q', 'ruby'], ['lang', 'en']])
req.body            # => "q=ruby&lang=en"

req.set_form_data(q: ['ruby', 'perl'], lang: 'en')
req.body            # => "q=ruby&q=perl&lang=en"

req.set_form_data([['q', 'ruby'], ['q', 'perl'], ['lang', 'en']])
req.body            # => "q=ruby&q=perl&lang=en"

With string argument sep also given, uses that string as the separator:

req.set_form_data({q: 'ruby', lang: 'en'}, '|')
req.body # => "q=ruby|lang=en"

Net::HTTPHeader#form_data= is an alias for Net::HTTPHeader#set_form_data.

# File lib/net/http/header.rb, line 812
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(length) → length

set_range(offset, length) → range

set_range(begin..length) → range

Sets the value for field 'Range'; see Range request header:

With argument length:

req = Net::HTTP::Get.new(uri)
req.set_range(100)      # => 100
req['Range']            # => "bytes=0-99"

With arguments offset and length:

req.set_range(100, 100) # => 100...200
req['Range']            # => "bytes=100-199"

With argument range:

req.set_range(100..199) # => 100..199
req['Range']            # => "bytes=100-199"

Net::HTTPHeader#range= is an alias for Net::HTTPHeader#set_range.

# File lib/net/http/header.rb, line 576
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 ()

Returns the trailing (‘subtype’) part of the media type from the value of field 'Content-Type', or nil if no such field exists; see Content-Type response header:

res = Net::HTTP.get_response(hostname, '/todos/1')
res['content-type'] # => "application/json; charset=utf-8"
res.sub_type        # => "json"

# File lib/net/http/header.rb, line 738
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 ()

Returns a hash of the key/value pairs:

req = Net::HTTP::Get.new(uri)
req.to_hash
# =>
{"accept-encoding"=>["gzip;q=1.0,deflate;q=0.6,identity;q=0.3"],
 "accept"=>["*/*"],
 "user-agent"=>["Ruby"],
 "host"=>["jsonplaceholder.typicode.com"]}

# File lib/net/http/header.rb, line 477
def to_hash
  @header.dup
end

type_params ()

Returns the trailing (‘parameters’) part of the value of field 'Content-Type', or nil if no such field exists; see Content-Type response header:

res = Net::HTTP.get_response(hostname, '/todos/1')
res['content-type'] # => "application/json; charset=utf-8"
res.type_params     # => {"charset"=>"utf-8"}

# File lib/net/http/header.rb, line 753
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