mimeparse

This module provides basic functions for handling mime-types. It can handle matching mime-types against a list of media-ranges. See section 14.1 of the HTTP specification [RFC 2616] for a complete explanation.

http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.1

A port to JavaScript of Joe Gregorio's MIME-Type Parser:

http://code.google.com/p/mimeparse/

Ported by J. Chris Anderson [e-mail], targeting the Spidermonkey runtime.

Ported to Chiron, Narwhal, Node by Kris Kowal.

http://github.com/kriskowal/mimeparse

Installation

Install <http://github.com/isaacs/npm>

npm install mimeparse

The API

parseMimeType(mimeType)

Carves up a mime-type and returns an Array of the
[type, subtype, params] where "params" is a Hash of all
the parameters for the media range.

For example, the media range "application/xhtml;q=0.5" would
get parsed into::

    ["application", "xhtml", { "q" : "0.5" }]

parseMediaRange(range)

Carves up a media range and returns an Array of the
[type, subtype, params] where "params" is a Object with
all the parameters for the media range.

For example, the media range "application/*;q=0.5" would
get parsed into::

    ["application", "*", { "q" : "0.5" }]

In addition this function also guarantees that there
is a value for "q" in the params dictionary, filling it
in with a proper default if necessary.

fitnessAndQualityParsed(mimeType, parsedRanges)

Find the best match for a given mime-type against
a list of media_ranges that have already been
parsed by parseMediaRange(). Returns an array of
the fitness value and the value of the 'q' quality
parameter of the best match, or (-1, 0) if no match
was found. Just as for qualityParsed(), 'parsed_ranges'
must be a list of parsed media ranges.

qualityParsed(mimeType, parsedRanges)

Find the best match for a given mime-type against
a list of media_ranges that have already been
parsed by parseMediaRange(). Returns the
'q' quality parameter of the best match, 0 if no
match was found. This function bahaves the same as quality()
except that 'parsedRanges' must be a list of
parsed media ranges.

quality(mimeType, ranges)

Returns the quality 'q' of a mime-type when compared
against the media-ranges in ranges. For example::

    >>> quality('text/html','text/*;q=0.3, text/html;q=0.7, text/html;level=1, text/html;level=2;q=0.4, *\/*;q=0.5')
    0.7

bestMatch(supported, header)

Takes a list of supported mime-types and finds the best
match for all the media-ranges listed in header. The value of
header must be a string that conforms to the format of the
HTTP Accept: header. The value of 'supported' is a list of
mime-types::

    >>> bestMatch(['application/xbel+xml', 'text/xml'], 'text/*;q=0.5,*\/*; q=0.1')
    'text/xml'