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.provisional?          # => false
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.

Public Class Methods

[](type_id, complete: false, registered: false) click to toggle source

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

# File lib/mime/types/registry.rb, line 13
def [](type_id, complete: false, registered: false)
  __types__[type_id, complete: complete, registered: registered]
end
add(*types) click to toggle source

#add against the default MIME::Types registry.

# File lib/mime/types/registry.rb, line 38
def add(*types)
  __types__.add(*types)
end
count() click to toggle source

#count against the default MIME::Types registry.

# File lib/mime/types/registry.rb, line 18
def count
  __types__.count
end
each() { |t| ... } click to toggle source

#each against the default MIME::Types registry.

# File lib/mime/types/registry.rb, line 23
def each
  if block_given?
    __types__.each { |t| yield t }
  else
    enum_for(:each)
  end
end
new() click to toggle source

Creates a new MIME::Types registry.

# File lib/mime/types.rb, line 74
def initialize
  @type_variants = Container.new
  @extension_index = Container.new
end
of(filename)
Alias for: type_for
type_for(filename) click to toggle source

#type_for against the default MIME::Types registry.

# File lib/mime/types/registry.rb, line 32
def type_for(filename)
  __types__.type_for(filename)
end
Also aliased as: of

Private Class Methods

__instances__() click to toggle source
# File lib/mime/types/registry.rb, line 74
def __instances__
  @__instances__ ||= Set.new
end
__types__() click to toggle source
# File lib/mime/types/registry.rb, line 54
def __types__
  (defined?(@__types__) && @__types__) || load_default_mime_types
end
lazy_load?() click to toggle source
# File lib/mime/types/registry.rb, line 44
  def lazy_load?
    return unless ENV.key?("RUBY_MIME_TYPES_LAZY_LOAD")

    MIME::Types.logger.warn <<-WARNING.chomp.strip
      Lazy loading ($RUBY_MIME_TYPES_LAZY_LOAD) is deprecated and will be removed.
    WARNING

    (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/registry.rb, line 64
def load_default_mime_types(mode = load_mode)
  if (@__types__ = MIME::Types::Cache.load)
    __instances__.add(@__types__)
  else
    @__types__ = MIME::Types::Loader.load(mode)
    MIME::Types::Cache.save(@__types__)
  end
  @__types__
end
load_mode() click to toggle source
# File lib/mime/types/full.rb, line 10
def load_mode
  {columnar: false}
end
reindex_extensions(type) click to toggle source
# File lib/mime/types/registry.rb, line 78
def reindex_extensions(type)
  __instances__.each do |instance|
    instance.send(:reindex_extensions!, type)
  end
  true
end

Public Instance Methods

[](type_id, complete: false, registered: false) 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. Current definitions sort before obsolete ones;
4. Obsolete definitions with use-instead clauses sort before those
   without;
5. Obsolete definitions use-instead clauses are compared.
6. Sort on name.
# File lib/mime/types.rb, line 124
def [](type_id, complete: false, registered: false)
  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, complete, registered).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 166
def add(*types)
  quiet = ((types.last == :silent) || (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.inject(Set.new, :+).to_a, 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 187
  def add_type(type, quiet = false)
    if !quiet && @type_variants[type.simplified].include?(type)
      MIME::Types.logger.warn <<-WARNING.chomp.strip
        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 80
def count
  @type_variants.values.inject(0) { |a, e| a + e.size }
end
each() { |t| ... } click to toggle source

Iterates through the type variants.

# File lib/mime/types.rb, line 89
def each
  if block_given?
    @type_variants.each_value { |tv| tv.each { |t| yield t } }
  else
    enum_for(:each)
  end
end
of(filename)
Alias for: type_for
type_for(filename) 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]
# File lib/mime/types.rb, line 152
def type_for(filename)
  Array(filename).flat_map { |fn|
    @extension_index[fn.chomp.downcase[/\.?([^.]*?)$/, 1]]
  }.compact.inject(Set.new, :+).sort { |a, b|
    a.priority_compare(b)
  }
end
Also aliased as: of

Private Instance Methods

add_type_variant!(mime_type) click to toggle source
# File lib/mime/types.rb, line 200
def add_type_variant!(mime_type)
  @type_variants.add(mime_type.simplified, mime_type)
end
index_extensions!(mime_type) click to toggle source
# File lib/mime/types.rb, line 210
def index_extensions!(mime_type)
  mime_type.extensions.each { |ext| @extension_index.add(ext, mime_type) }
end
match(pattern) click to toggle source
# File lib/mime/types.rb, line 220
def match(pattern)
  @type_variants.select { |k, _|
    k =~ pattern
  }.values.inject(Set.new, :+)
end
prune_matches(matches, complete, registered) click to toggle source
# File lib/mime/types.rb, line 214
def prune_matches(matches, complete, registered)
  matches.delete_if { |e| !e.complete? } if complete
  matches.delete_if { |e| !e.registered? } if registered
  matches
end
reindex_extensions!(mime_type) click to toggle source
# File lib/mime/types.rb, line 204
def reindex_extensions!(mime_type)
  return unless @type_variants[mime_type.simplified].include?(mime_type)

  index_extensions!(mime_type)
end