Module: Rack::Accept::Header

Includes:
PublicInstanceMethods
Included in:
Charset, Encoding, Language, MediaType
Defined in:
lib/rack/accept/header.rb

Overview

Contains methods that are useful for working with Accept-style HTTP headers. The MediaType, Charset, Encoding, and Language classes all mixin this module.

Defined Under Namespace

Modules: PublicInstanceMethods

Instance Attribute Summary

Attributes included from PublicInstanceMethods

#qvalues

Class Method Summary collapse

Methods included from PublicInstanceMethods

#accept?, #best_of, #initialize, #name, #qvalue, #sort, #sort_with_qvalues, #to_s, #value, #values

Class Method Details

.join(qvalues) ⇒ Object

Returns a string suitable for use as the value of an Accept-style HTTP header from the map of acceptable values to their respective quality factors (qvalues). The parse method may be used on the resulting string to obtain a hash that is the equivalent of the one provided.



31
32
33
 
# File 'lib/rack/accept/header.rb', line 31

def join(qvalues)
  qvalues.map {|k, v| k + (v == 1 ? '' : ";q=#{v}") }.join(', ')
end

.normalize_qvalue(q) ⇒ Object

Converts 1.0 and 0.0 qvalues to 1 and 0 respectively. Used to maintain consistency across qvalue methods.



59
60
61
 
# File 'lib/rack/accept/header.rb', line 59

def normalize_qvalue(q)
  (q == 1 || q == 0) && q.is_a?(Float) ? q.to_i : q
end

.parse(header) ⇒ Object

Parses the value of an Accept-style request header into a hash of acceptable values and their respective quality factors (qvalues). The join method may be used on the resulting hash to obtain a header string that is the semantic equivalent of the one provided.



10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
 
# File 'lib/rack/accept/header.rb', line 10

def parse(header)
  qvalues = {}

  header.to_s.split(/,\s*/).each do |part|
    m = /^([^\s,]+?)(?:\s*;\s*q\s*=\s*(\d+(?:\.\d+)?))?$/.match(part)

    if m
      qvalues[m[1].downcase] = normalize_qvalue((m[2] || 1).to_f)
    else
      raise "Invalid header value: #{part.inspect}"
    end
  end

  qvalues
end

.parse_media_type(media_type) ⇒ Object

Parses a media type string into its relevant pieces. The return value will be an array with three values: 1) the content type, 2) the content subtype, and 3) the media type parameters. An empty array is returned if no match can be made.



40
41
42
43
 
# File 'lib/rack/accept/header.rb', line 40

def parse_media_type(media_type)
  m = media_type.to_s.match(/^([a-z*]+)\/([a-z0-9*\-.+]+)(?:;([a-z0-9=;]+))?$/)
  m ? [m[1], m[2], m[3] || ''] : []
end

.parse_range_params(params) ⇒ Object

Parses a string of media type range parameters into a hash of parameters to their respective values.



48
49
50
51
52
53
54
 
# File 'lib/rack/accept/header.rb', line 48

def parse_range_params(params)
  params.split(';').inject({}) do |m, p|
    k, v = p.split('=', 2)
    m[k] = v if v
    m
  end
end