class MIME::Types

MIME::Types is a registry of MIME types. It is both a class (created with ::new) and a default registry (loaded automatically or through interactions with #[] and #type_for).

The Default mime-types Registry

The default mime-types registry is loaded automatically when the library is required (require 'mime/types'), but it may be lazily loaded (loaded on first use) with the use of the environment variable RUBY_MIME_TYPES_LAZY_LOAD having any value other than false. The initial startup is about 14× faster (~10 ms vs ~140 ms), but the registry will be loaded at some point in the future.

The default mime-types registry can also be loaded from a Marshal cache file specific to the version of MIME::Types being loaded. This will be handled automatically with the use of a file referred to in the environment variable RUBY_MIME_TYPES_CACHE. MIME::Types will attempt to load the registry from this cache file (MIME::Type::Cache.load); if it cannot be loaded (because the file does not exist, there is an error, or the data is for a different version of mime-types), the default registry will be loaded from the normal JSON version and then the cache file will be written to the location indicated by RUBY_MIME_TYPES_CACHE. Cache file loads just over 4½× faster (~30 ms vs ~140 ms). loads.

Notes:

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'

Constants

VERSION

The release version of Ruby MIME::Types

Attributes

logger[RW]

Configure the MIME::Types logger. This defaults to an instance of a logger that passes messages (unformatted) through to Kernel#warn.

data_version[R]

The data version.

Public Class Methods

[](type_id, flags = {}) click to toggle source

#[] against the default MIME::Types registry.

# File lib/mime/types.rb, line 236
def [](type_id, flags = {})
  __types__[type_id, flags]
end
add(*types) click to toggle source

#add against the default MIME::Types registry.

# File lib/mime/types.rb, line 261
def add(*types)
  __types__.add(*types)
end
cache_file() click to toggle source

Returns the currently defined cache file, if any.

This method has been deprecated and will be removed in mime-types 3.0.

# File lib/mime/types.rb, line 268
def cache_file
  MIME::Types.deprecated(self, __method__)
  ENV['RUBY_MIME_TYPES_CACHE']
end
count() click to toggle source

#count against the default MIME::Types registry.

# File lib/mime/types.rb, line 241
def count
  __types__.count
end
each() { |t| ... } click to toggle source

#each against the default MIME::Types registry.

# File lib/mime/types.rb, line 246
def each
  if block_given?
    __types__.each { |t| yield t }
  else
    enum_for(:each)
  end
end
load_from_file(filename) click to toggle source

Load MIME::Types from a v1 file registry.

This method has been deprecated and will be removed in mime-types 3.0.

# File lib/mime/types.rb, line 230
def load_from_file(filename)
  MIME::Types.deprecated(self, __method__)
  MIME::Types::Loader.load_from_v1(filename)
end
new() click to toggle source

Creates a new MIME::Types registry.

# File lib/mime/types.rb, line 72
def initialize
  @type_variants    = Container.new
  @extension_index  = Container.new
  @data_version     = VERSION.dup.freeze
end
of(filename, platform = false)
Alias for: type_for
type_for(filename, platform = false) click to toggle source

#type_for against the default MIME::Types registry.

# File lib/mime/types.rb, line 255
def type_for(filename, platform = false)
  __types__.type_for(filename, platform)
end
Also aliased as: of

Private Class Methods

__types__() click to toggle source
# File lib/mime/types.rb, line 287
def __types__
  (defined?(@__types__) and @__types__) or load_default_mime_types
end
lazy_load?() click to toggle source
# File lib/mime/types.rb, line 283
def lazy_load?
  (lazy = ENV['RUBY_MIME_TYPES_LAZY_LOAD']) && (lazy != 'false')
end
load_default_mime_types(mode = load_mode()) click to toggle source
# File lib/mime/types.rb, line 297
def load_default_mime_types(mode = load_mode())
  @__types__ = MIME::Types::Cache.load
  unless @__types__
    @__types__ = MIME::Types::Loader.load(mode)
    MIME::Types::Cache.save(@__types__)
  end
  @__types__
end
load_mode() click to toggle source
# File lib/mime/types.rb, line 292
def load_mode
  {}
end

Public Instance Methods

[](type_id, flags = {}) click to toggle source

Returns a list of MIME::Type objects, which may be empty. The optional flag parameters are :complete (finds only complete MIME::Type objects) and :registered (finds only MIME::Types that are registered). 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.

An additional flag of :platform (finds only MIME::Types for the current platform) is currently supported but deprecated.

# File lib/mime/types.rb, line 141
def [](type_id, flags = {})
  if flags[:platform]
    MIME::Types.deprecated(self, __method__, 'using the :platform flag')
  end

  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) click to toggle source

Add one or more MIME::Type objects to the set of known types. If the type is already known, a warning will be displayed.

The last parameter may be the value :silent or true which will suppress duplicate MIME type warnings.

# File lib/mime/types.rb, line 192
def add(*types)
  quiet = ((types.last == :silent) or (types.last == true))

  types.each do |mime_type|
    case mime_type
    when true, false, nil, Symbol
      nil
    when MIME::Types
      variants = mime_type.instance_variable_get(:@type_variants)
      add(*variants.values.flatten, quiet)
    when Array
      add(*mime_type, quiet)
    else
      add_type(mime_type, quiet)
    end
  end
end
add_type(type, quiet = false) click to toggle source

Add a single MIME::Type object to the set of known types. If the type is already known, a warning will be displayed. The quiet parameter may be a truthy value to suppress that warning.

# File lib/mime/types.rb, line 213
  def add_type(type, quiet = false)
    if !quiet and @type_variants[type.simplified].include?(type)
      MIME::Types.logger.warn <<-warning
Type #{type} is already registered as a variant of #{type.simplified}.
      warning
    end

    add_type_variant!(type)
    index_extensions!(type)
  end
count() click to toggle source

Returns the number of known type variants.

# File lib/mime/types.rb, line 97
def count
  @type_variants.values.reduce(0) { |m, o| m + o.size }
end
each() { |t| ... } click to toggle source

Iterates through the type variants.

# File lib/mime/types.rb, line 102
def each
  if block_given?
    @type_variants.each_value { |tv| tv.each { |t| yield t } }
  else
    enum_for(:each)
  end
end
of(filename, platform = false)
Alias for: type_for
type_for(filename, platform = false) click to toggle source

Return the list of MIME::Types which belongs to the file based on its filename extension. If there is no extension, the filename will be used as the matching criteria on its own.

This will always return a merged, flatten, priority sorted, unique array.

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

If platform is true, then only file types that are specific to the current platform will be returned. This parameter has been deprecated.

# File lib/mime/types.rb, line 173
def type_for(filename, platform = false)
  types = Array(filename).flat_map { |fn|
    @extension_index[fn.chomp.downcase[/\.?([^.]*?)$/, 1]]
  }.compact.sort { |a, b| a.priority_compare(b) }.uniq

  if platform
    MIME::Types.deprecated(self, __method__, 'using the platform parameter')
    types.select(&:platform?)
  else
    types
  end
end
Also aliased as: of

Private Instance Methods

add_type_variant!(mime_type) click to toggle source
# File lib/mime/types.rb, line 309
def add_type_variant!(mime_type)
  @type_variants[mime_type.simplified] << mime_type
end
index_extensions!(mime_type) click to toggle source
# File lib/mime/types.rb, line 313
def index_extensions!(mime_type)
  mime_type.extensions.each { |ext| @extension_index[ext] << mime_type }
end
match(pattern) click to toggle source
# File lib/mime/types.rb, line 324
def match(pattern)
  @type_variants.select { |k, _| k =~ pattern }.values.flatten
end
prune_matches(matches, flags) click to toggle source
# File lib/mime/types.rb, line 317
def prune_matches(matches, flags)
  matches.delete_if { |e| !e.complete? } if flags[:complete]
  matches.delete_if { |e| !e.platform? } if flags[:platform]
  matches.delete_if { |e| !e.registered? } if flags[:registered]
  matches
end