Class: MIME::Types

Inherits:
Object
  • Object
show all
Extended by:
Enumerable
Defined in:
lib/mime/types.rb

Overview

MIME::Types

MIME types are used in MIME-compliant communications, as in e-mail or HTTP traffic, to indicate the type of content which is transmitted. MIME::Types provides the ability for detailed information about MIME entities (provided as a set of MIME::Type objects) to be determined and used programmatically. There are many types defined by RFCs and vendors, so the list is long but not complete; don’t hesitate to ask to add additional information. This library follows the IANA collection of MIME types (see below for reference).

Description

MIME types are used in MIME entities, as in email or HTTP traffic. It is useful at times to have information available about MIME types (or, inversely, about files). A MIME::Type stores the known information about one MIME type.

Usage

require 'mime/types'

plaintext = MIME::Types['text/plain']
print plaintext.media_type           # => 'text'
print plaintext.sub_type             # => 'plain'

puts plaintext.extensions.join(" ")  # => 'asc txt c cc h hh cpp'

puts plaintext.encoding              # => 8bit
puts plaintext.binary?               # => false
puts plaintext.ascii?                # => true
puts plaintext.obsolete?             # => false
puts plaintext.registered?           # => true
puts plaintext == 'text/plain'       # => true
puts MIME::Type.simplified('x-appl/x-zip') # => 'appl/zip'

This module is built to conform to the MIME types of RFCs 2045 and 2231. It follows the official IANA registry at www.iana.org/assignments/media-types/ and ftp.iana.org/assignments/media-types with some unofficial types added from the the collection at www.ltsw.se/knbase/internet/mime.htp

Defined Under Namespace

Classes: CacheContainer, HashWithArrayDefault

Constant Summary collapse

VERSION =

The released version of Ruby MIME::Types

MIME::Type::VERSION
DATA_VERSION = 
(VERSION.to_f * 100).to_i
TEXT_FORMAT_RE =

The regular expression used to match a file-based MIME type definition.

%r{
  \A
  \s*
  ([*])?                                 # 0: Unregistered?
  (!)?                                   # 1: Obsolete?
  (?:(\w+):)?                            # 2: Platform marker
  #{MIME::Type::MEDIA_TYPE_RE}?          # 3,4: Media type
  (?:\s+@([^\s]+))?                      # 5: Extensions
  (?:\s+:(#{MIME::Type::ENCODING_RE}))?  # 6: Encoding
  (?:\s+'(.+))?                          # 7: URL list
  (?:\s+=(.+))?                          # 8: Documentation
  (?:\s*([#].*)?)?
  \s*
  \z
}x

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(data_version = DATA_VERSION) ⇒ Types

Returns a new instance of Types.



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# File 'lib/mime/types.rb', line 591

def initialize(data_version = DATA_VERSION)
  @type_variants    = HashWithArrayDefault.new
  @extension_index  = HashWithArrayDefault.new
  @data_version     = data_version
end

Instance Attribute Details

#data_version ⇒ Object (readonly)

The data version.



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# File 'lib/mime/types.rb', line 568

def data_version
  @data_version
end

Class Method Details

.[](type_id, flags = {}) ⇒ Object

Returns a list of MIME::Type objects, which may be empty. The optional flag parameters are :complete (finds only complete MIME::Type objects) and :platform (finds only MIME::Types for the current platform). It is possible for multiple matches to be returned for either type (in the example below, ‘text/plain’ returns two values – one for the general case, and one for VMS systems.

puts "\nMIME::Types['text/plain']"
MIME::Types['text/plain'].each { |t| puts t.to_a.join(", ") }

puts "\nMIME::Types[/^image/, :complete => true]"
MIME::Types[/^image/, :complete => true].each do |t|
  puts t.to_a.join(", ")
end



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# File 'lib/mime/types.rb', line 849

def [](type_id, flags = {})
  __types__[type_id, flags]
end

.add(*types) ⇒ Object

Add one or more MIME::Type objects to the set of known types. Each type should be experimental (e.g., ‘application/x-ruby’). If the type is already known, a warning will be displayed.

<strong>Please inform the maintainer of this module when registered types are missing.</strong>



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# File 'lib/mime/types.rb', line 888

def add(*types)
  __types__.add(*types)
end

.add_type_variant(mime_type) ⇒ Object

:nodoc:



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# File 'lib/mime/types.rb', line 722

def add_type_variant(mime_type) #:nodoc:
  __types__.add_type_variant(mime_type)
end

.cache_file ⇒ Object

Returns the currently defined cache file, if any.



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# File 'lib/mime/types.rb', line 893

def cache_file
  ENV['RUBY_MIME_TYPES_CACHE']
end

.count ⇒ Object 



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# File 'lib/mime/types.rb', line 855

def count
  __types__.count
end

.each ⇒ Object 



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# File 'lib/mime/types.rb', line 859

def each
  __types__.each {|t| yield t }
end

.index_extensions(mime_type) ⇒ Object

:nodoc:



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# File 'lib/mime/types.rb', line 726

def index_extensions(mime_type) #:nodoc:
  __types__.index_extensions(mime_type)
end

.load_from_file(filename) ⇒ Object

Build the type list from a file in the format:

[*][!][os:]mt/st[<ws>@ext][<ws>:enc][<ws>'url-list][<ws>=docs]

*

An unofficial MIME type. This should be used if and only if the MIME type is not properly specified (that is, not under either x-type or vnd.name.type).

!

An obsolete MIME type. May be used with an unofficial MIME type.

os:

Platform-specific MIME type definition.

mt

The media type.

st

The media subtype.

<ws>@ext

The list of comma-separated extensions.

<ws>:enc

The encoding.

<ws>‘url-list

The list of comma-separated URLs.

<ws>=docs

The documentation string.

That is, everything except the media type and the subtype is optional. The more information that’s available, though, the richer the values that can be provided.



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# File 'lib/mime/types.rb', line 784

def load_from_file(filename) #:nodoc:
  if defined? ::Encoding
    data = File.open(filename, 'r:UTF-8:-') { |f| f.read }
  else
    data = File.open(filename) { |f| f.read }
  end
  data = data.split($/)
  mime = MIME::Types.new
  data.each_with_index { |line, index|
    item = line.chomp.strip
    next if item.empty?

    begin
      m = TEXT_FORMAT_RE.match(item).captures
    rescue Exception
      puts "#{filename}:#{index}: Parsing error in MIME type definitions."
      puts "=> #{line}"
      raise
    end

    unregistered, obsolete, platform, mediatype, subtype, extensions,
      encoding, urls, docs, comment = *m

    if mediatype.nil?
      if comment.nil?
        puts "#{filename}:#{index}: Parsing error in MIME type definitions."
        puts "=> #{line}"
        raise RuntimeError
      end

      next
    end

    extensions &&= extensions.split(/,/)
    urls &&= urls.split(/,/)

    mime_type = MIME::Type.new("#{mediatype}/#{subtype}") do |t|
      t.extensions  = extensions
      t.encoding    = encoding
      t.system      = platform
      t.obsolete    = obsolete
      t.registered  = false if unregistered
      t.docs        = docs
      t.url         = urls
    end

    mime.add(mime_type)
  }
  mime
end

.of(filename, platform = false) ⇒ Object

A synonym for MIME::Types.type_for



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# File 'lib/mime/types.rb', line 878

def of(filename, platform = false)
  __types__.type_for(filename, platform)
end

.type_for(filename, platform = false) ⇒ Object

Return the list of MIME::Types which belongs to the file based on its filename extension. If platform is true, then only file types that are specific to the current platform will be returned.

This will always return an array.

puts "MIME::Types.type_for('citydesk.xml')
  => [application/xml, text/xml]
puts "MIME::Types.type_for('citydesk.gif')
  => [image/gif]



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# File 'lib/mime/types.rb', line 873

def type_for(filename, platform = false)
  __types__.type_for(filename, platform)
end

Instance Method Details

#[](type_id, flags = {}) ⇒ Object

Returns a list of MIME::Type objects, which may be empty. The optional flag parameters are :complete (finds only complete MIME::Type objects) and :platform (finds only MIME::Types for the current platform). It is possible for multiple matches to be returned for either type (in the example below, ‘text/plain’ returns two values – one for the general case, and one for VMS systems.

puts "\nMIME::Types['text/plain']"
MIME::Types['text/plain'].each { |t| puts t.to_a.join(", ") }

puts "\nMIME::Types[/^image/, :complete => true]"
MIME::Types[/^image/, :complete => true].each do |t|
  puts t.to_a.join(", ")
end

If multiple type definitions are returned, returns them sorted as follows:

1. Complete definitions sort before incomplete ones;
2. IANA-registered definitions sort before LTSW-recorded
   definitions.
3. Generic definitions sort before platform-specific ones;
4. Current definitions sort before obsolete ones;
5. Obsolete definitions with use-instead clauses sort before those
   without;
6. Obsolete definitions use-instead clauses are compared.
7. Sort on name.



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# File 'lib/mime/types.rb', line 648

def [](type_id, flags = {})
  matches = case type_id
            when MIME::Type
              @type_variants[type_id.simplified]
            when Regexp
              match(type_id)
            else
              @type_variants[MIME::Type.simplified(type_id)]
            end

  prune_matches(matches, flags).sort { |a, b| a.priority_compare(b) }
end

#add(*types) ⇒ Object

Add one or more MIME::Type objects to the set of known types. Each type should be experimental (e.g., ‘application/x-ruby’). If the type is already known, a warning will be displayed.

<strong>Please inform the maintainer of this module when registered types are missing.</strong>



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# File 'lib/mime/types.rb', line 689

def add(*types)
  types.each do |mime_type|
    if mime_type.kind_of? MIME::Types
      add(*mime_type.defined_types)
    else
      if @type_variants.include?(mime_type.simplified)
        if @type_variants[mime_type.simplified].include?(mime_type)
          warn "Type #{mime_type} already registered as a variant of #{mime_type.simplified}." unless defined? MIME::Types::LOAD
        end
      end
      add_type_variant(mime_type)
      index_extensions(mime_type)
    end
  end
end

#add_type_variant(mime_type) ⇒ Object

:nodoc:



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# File 'lib/mime/types.rb', line 597

def add_type_variant(mime_type) #:nodoc:
  @type_variants[mime_type.simplified] << mime_type
end

#count ⇒ Object

Returns the number of known types. A shortcut of MIME::Types.size. (Keep in mind that this is memory intensive, cache the result to spare resources)



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# File 'lib/mime/types.rb', line 612

def count
  defined_types.size
end

#defined_types ⇒ Object

:nodoc:



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# File 'lib/mime/types.rb', line 605

def defined_types #:nodoc:
  @type_variants.values.flatten
end

#each ⇒ Object 



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# File 'lib/mime/types.rb', line 616

def each
 defined_types.each { |t| yield t }
end

#index_extensions(mime_type) ⇒ Object

:nodoc:



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# File 'lib/mime/types.rb', line 601

def index_extensions(mime_type) #:nodoc:
  mime_type.extensions.each { |ext| @extension_index[ext] << mime_type }
end

#of(filename, platform = false) ⇒ Object

A synonym for MIME::Types.type_for



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# File 'lib/mime/types.rb', line 679

def of(filename, platform = false)
  type_for(filename, platform)
end

#type_for(filename, platform = false) ⇒ Object

Return the list of MIME::Types which belongs to the file based on its filename extension. If platform is true, then only file types that are specific to the current platform will be returned.

This will always return an array.

puts "MIME::Types.type_for('citydesk.xml')
  => [application/xml, text/xml]
puts "MIME::Types.type_for('citydesk.gif')
  => [image/gif]



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# File 'lib/mime/types.rb', line 671

def type_for(filename, platform = false)
  ext = filename.chomp.downcase.gsub(/.*\./o, '')
  list = @extension_index[ext]
  list.delete_if { |e| not e.platform? } if platform
  list
end