Object
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 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.
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'
Caching of MIME::Types registries is advisable if you will be loading the default registry relatively frequently. With the class methods on MIME::Types::Cache, any MIME::Types registry can be marshaled quickly and easily.
The cache is invalidated on a per-version basis; a cache file for version 2.0 will not be reused with version 2.0.1.
The release version of Ruby MIME::Types
MIME::Types#[] against the default MIME::Types registry.
# File lib/mime/types.rb, line 228 def [](type_id, flags = {}) __types__[type_id, flags] end
MIME::Types#add against the default MIME::Types registry.
# File lib/mime/types.rb, line 249 def add(*types) __types__.add(*types) end
Returns the currently defined cache file, if any.
# File lib/mime/types.rb, line 254 def cache_file MIME.deprecated(self, __method__) ENV['RUBY_MIME_TYPES_CACHE'] end
MIME::Types#count against the default MIME::Types registry.
# File lib/mime/types.rb, line 233 def count __types__.count end
MIME::Types#each against the default MIME::Types registry.
# File lib/mime/types.rb, line 238 def each __types__.each {|t| yield t } end
Load MIME::Types from a v1 file registry.
This method has been deprecated.
# File lib/mime/types.rb, line 222 def load_from_file(filename) MIME.deprecated(self, __method__) MIME::Types::Loader.load_from_v1(filename) end
Creates a new MIME::Types registry.
# File lib/mime/types.rb, line 71 def initialize @type_variants = Container.new @extension_index = Container.new @data_version = VERSION.dup.freeze end
MIME::Types#type_for against the default MIME::Types registry.
# File lib/mime/types.rb, line 243 def type_for(filename, platform = false) __types__.type_for(filename, platform) end
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 133 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 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 185 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 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 206 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
Returns the number of known type variants.
# File lib/mime/types.rb, line 93 def count @type_variants.values.reduce(0) { |m, o| m + o.size } end
Iterates through the type variants.
# File lib/mime/types.rb, line 98 def each @type_variants.values.each { |tv| tv.each { |t| yield t } } end
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 165 def type_for(filename, platform = false) types = Array(filename).flat_map { |fn| @extension_index[File.basename(fn.chomp.downcase).gsub(/.*\./, '')] }.compact.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
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