libs/http/luasrc/http/protocol/mime.lua

   1 --[[
   2
   3 HTTP protocol implementation for LuCI - mime handling
   4 (c) 2008 Freifunk Leipzig / Jo-Philipp Wich <xm@leipzig.freifunk.net>
   5
   6 Licensed under the Apache License, Version 2.0 (the "License");
   7 you may not use this file except in compliance with the License.
   8 You may obtain a copy of the License at
   9
  10         http://www.apache.org/licenses/LICENSE-2.0
  11
  12 $Id$
  13
  14 ]]--
  15
  16 module("luci.http.protocol.mime", package.seeall)
  17
  18 -- MIME mapping
  19 MIME_TYPES = {
  20     ["txt"]   = "text/plain";
  21     ["js"]    = "text/javascript";
  22     ["css"]   = "text/css";
  23     ["htm"]   = "text/html";
  24     ["html"]  = "text/html";
  25
  26     ["gif"]   = "image/gif";
  27     ["png"]   = "image/png";
  28     ["jpg"]   = "image/jpeg";
  29     ["jpeg"]  = "image/jpeg";
  30
  31     ["xml"]   = "application/xml";
  32 }
  33
  34 -- extract extension from a filename and return corresponding mime-type or
  35 -- "application/octet-stream" if the extension is unknown
  36 function to_mime(filename)
  37         if type(filename) == "string" then
  38                 local ext = filename:match("[^%.]+$")
  39
  40                 if ext and MIME_TYPES[ext:lower()] then
  41                         return MIME_TYPES[ext:lower()]
  42                 end
  43         end
  44
  45         return "application/octet-stream"
  46 end
  47
  48 -- return corresponding extension for a given mime type or nil if the
  49 -- given mime-type is unknown
  50 function to_ext(mimetype)
  51         if type(mimetype) == "string" then
  52                 for ext, type in luci.util.kspairs( MIME_TYPES ) do
  53                         if type == mimetype then
  54                                 return ext
  55                         end
  56                 end
  57         end
  58
  59         return nil
  60 end