Class: MIME::Types

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

Overview

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

  • The loading of the default registry is not atomic; when using a multi-threaded environment, it is recommended that lazy loading is not used and mime-types is loaded as early as possible.

  • Cache files should be specified per application in a multiprocess environment and should be initialized during deployment or before forking to minimize the chance that the multiple processes will be trying to write to the same cache file at the same time, or that two applications that are on different versions of mime-types would be thrashing the cache.

  • Unless cache files are preinitialized, the application using the mime-types cache file must have read/write permission to the cache file.

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'

Defined Under Namespace

Classes: Cache, Container, Loader

Constant Summary collapse

VERSION =

The release version of Ruby MIME::Types

MIME::Type::VERSION

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Types

Creates a new MIME::Types registry.



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# File 'lib/mime/types.rb', line 72

def initialize
  @type_variants    = Container.new
  @extension_index  = Container.new
  @data_version     = VERSION.dup.freeze
end

Instance Attribute Details

#data_version ⇒ Object (readonly)

The data version.



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# File 'lib/mime/types.rb', line 69

def data_version
  @data_version
end

Class Method Details

.[](type_id, flags = {}) ⇒ Object

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



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# File 'lib/mime/types.rb', line 229

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

.add(*types) ⇒ Object

MIME::Types#add against the default MIME::Types registry.



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# File 'lib/mime/types.rb', line 250

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

.add_type_variant(mime_type) ⇒ Object

:nodoc:



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# File 'lib/mime/types.rb', line 260

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 255

def cache_file
  MIME.deprecated(self, __method__)
  ENV['RUBY_MIME_TYPES_CACHE']
end

.count ⇒ Object

MIME::Types#count against the default MIME::Types registry.



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# File 'lib/mime/types.rb', line 234

def count
  __types__.count
end

.each ⇒ Object

MIME::Types#each against the default MIME::Types registry.



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# File 'lib/mime/types.rb', line 239

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

.index_extensions(mime_type) ⇒ Object

:nodoc:



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# File 'lib/mime/types.rb', line 264

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

.load_from_file(filename) ⇒ Object

Load MIME::Types from a v1 file registry.

This method has been deprecated.



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# File 'lib/mime/types.rb', line 223

def load_from_file(filename)
  MIME.deprecated(self, __method__)
  MIME::Types::Loader.load_from_v1(filename)
end

.type_for(filename, platform = false) ⇒ Object Also known as: of

MIME::Types#type_for against the default MIME::Types registry.



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# File 'lib/mime/types.rb', line 244

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 :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.



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# File 'lib/mime/types.rb', line 134

def [](type_id, flags = {})
  if flags[:platform]
    MIME.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) ⇒ Object

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.



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# File 'lib/mime/types.rb', line 186

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(mime_type, quiet = false) ⇒ Object

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.



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# File 'lib/mime/types.rb', line 207

def add_type(mime_type, quiet = false)
  if !quiet and @type_variants[mime_type.simplified].include?(mime_type)
    warn("Type %s is already registered as a variant of %s." % [
      mime_type, mime_type.simplified ])
  end

  add_type_variant!(mime_type)
  index_extensions!(mime_type)
end

#add_type_variant(mime_type) ⇒ Object

:nodoc:



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# File 'lib/mime/types.rb', line 78

def add_type_variant(mime_type) # :nodoc:
  MIME.deprecated(self, __method__, :private)
  add_type_variant!(mime_type)
end

#count ⇒ Object

Returns the number of known type variants.



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# File 'lib/mime/types.rb', line 94

def count
  @type_variants.values.reduce(0) { |m, o| m + o.size }
end

#defined_types ⇒ Object

:nodoc:



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# File 'lib/mime/types.rb', line 88

def defined_types # :nodoc:
  MIME.deprecated(self, __method__)
  @type_variants.values.flatten
end

#each ⇒ Object

Iterates through the type variants.



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# File 'lib/mime/types.rb', line 99

def each
  @type_variants.values.each { |tv| tv.each { |t| yield t } }
end

#index_extensions(mime_type) ⇒ Object

:nodoc:



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# File 'lib/mime/types.rb', line 83

def index_extensions(mime_type) # :nodoc:
  MIME.deprecated(self, __method__, :private)
  index_extensions!(mime_type)
end

#of ⇒ Object

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.



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# File 'lib/mime/types.rb', line 179

def type_for(filename, platform = false)
  types = [ filename ].flatten.map { |fn|
    @extension_index[File.basename(fn.chomp.downcase).gsub(/.*\./o, '')]
  }.flatten.sort { |a, b| a.priority_compare(b) }.uniq

  if platform
    MIME.deprecated(self, __method__,
                    "using the platform parameter")
    types.select(&:platform?)
  else
    types
  end
end

#type_for(filename, platform = false) ⇒ Object

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.



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# File 'lib/mime/types.rb', line 166

def type_for(filename, platform = false)
  types = [ filename ].flatten.map { |fn|
    @extension_index[File.basename(fn.chomp.downcase).gsub(/.*\./o, '')]
  }.flatten.sort { |a, b| a.priority_compare(b) }.uniq

  if platform
    MIME.deprecated(self, __method__,
                    "using the platform parameter")
    types.select(&:platform?)
  else
    types
  end
end