`class MimeTypeLoader`

A class to assist with loading mime-type metadata.

Classes and Modules

class ExpansionError < ArgumentError: Raised when expansion processing fails.

Definitions

`def initialize(library)`

Initialize an empty extension map backed by named MIME type groups.

Signature

parameter　library　Object: The library.

Implementation

def initialize(library)
	@extensions = {}
	@library = library
end

`def self.extensions_for(types, library = MIME_TYPES)`

Find extensions associated with the given MIME types.

Signature

parameter　types　Array: The MIME type definitions to expand.
parameter　library　Hash: The named MIME type groups.
returns　Hash(String, String): A mapping from file extensions to content types.

Implementation

def self.extensions_for(types, library = MIME_TYPES)
	loader = self.new(library)
	loader.expand(types)
	return loader.extensions
end

`def add_extension(extension)`

Add an extension using its registered media type.

Signature

parameter　extension　String: The file extension.
returns　Protocol::Media::Registry::Record: The registered media type record.

Implementation

def add_extension(extension)
	# Normalize optional leading dots and case before constructing the File.extname-style key:
	extension = extension.delete_prefix(".").downcase
	
	if record = Protocol::Media::Registry.for_extension(extension)
		@extensions["." + extension] = record.type.to_s
		return record
	end
	
	raise ExpansionError.new("Unknown file extension: #{extension.inspect}")
end

`def expand(types)`

Expand named groups, file extensions, and explicit extension pairs into extension mappings.

Signature

parameter　types　Array: The MIME type definitions.
returns　Array: The supplied definitions.
raises　ExpansionError: If a definition cannot be expanded.

Implementation

def expand(types)
	types.each do |type|
		case type
		when Symbol
			self.expand(@library.fetch(type))
		when Array
			@extensions["." + type[0]] = type[1]
		when String
			self.add_extension(type)
		else
			raise ExpansionError.new("Unsupported MIME type definition: #{type.inspect}")
		end
	rescue ExpansionError
		raise
	rescue
		raise ExpansionError.new("#{self.class.name}: Error while processing #{type.inspect}!")
	end
end