lua-uri-data - data URI support for Lua URI library

       The class "uri.data" is used for URIs with the "data" scheme.  It inherits from the uri class.

       Some of the features of this module require the lua-datafilter(3) library to be installed, but URI
       objects can still be created from "data" URIs even if it isn't available.

       Any "data" URI containing an authority part is considered to be invalid, as is one whose path does not
       contain a comma.  If the URI has the ";base64" parameter, then the data must consist only of characters
       allowed in base64 encoded data (upper and lowercase ASCII letters, digits, and the forward slash and plus
       characters).

       All the methods defined in lua-uri(3) are supported.  The "userinfo", "host", and "port" methods will
       always return nil, and will throw an exception when passed anything other than nil.  The "path" method
       will throw an exception if given a new path which is nil or not valid for the "data" scheme.

       The following additional methods are supported:

       uri:data_bytes(...)
           Get or set the data stored in the URI.  The existing data is decoded and returned.  If a new value is
           supplied  it  must  be  a  string, and will cause the path of the URI to be changed to encode the new
           data.  The method will choose the encoding  which  will  result  in  the  smallest  URI,  unless  the
           datafilter module is not installed, in which case it will always use percent encoding.

           An  exception  is thrown if the datafilter module is not installed and the data in the URI is encoded
           as base64, although a data URI using percent encoding will not cause an exception.

           The data passed in and returned should not be encoded in any special way, that is taken  care  of  by
           the library.

       uri:data_media_type(...)
           Get  or  set  the  media type (MIME type) stored in the URI's path before the comma.  This should not
           include the ";base64" parameter, which will be included in the path automatically when appropriate.

           If there is no media type given in the URI then the default value of "text/plain" will  be  returned,
           and if there is no "charset" parameter given then the default ";charset=US-ASCII" will be included.

           The media type is encoded and decoded automatically by this method.

       lua-uri-data - data URI support for Lua URI library

       This class is based on "RFC 2397".

1.1                                                2012-00-00                                    LUA-URI-DATA(3)