oracular (3) XML::UM.3pm.gz

NAME

       XML::UM - Convert UTF-8 strings to any encoding supported by XML::Encoding

SYNOPSIS

        use XML::UM;

        # Set directory with .xml files that comes with XML::Encoding distribution
        # Always include the trailing slash!
        $XML::UM::ENCDIR = '/home1/enno/perlModules/XML-Encoding-1.01/maps/';

        # Create the encoding routine
        my $encode = XML::UM::get_encode (
               Encoding => 'ISO-8859-2',
               EncodeUnmapped => \&XML::UM::encode_unmapped_dec);

        # Convert a string from UTF-8 to the specified Encoding
        my $encoded_str = $encode->($utf8_str);

        # Remove circular references for garbage collection
        XML::UM::dispose_encoding ('ISO-8859-2');

DESCRIPTION

       This module provides methods to convert UTF-8 strings to any XML encoding that XML::Encoding supports. It
       creates mapping routines from the .xml files that can be found in the maps/ directory in the
       XML::Encoding distribution. Note that the XML::Encoding distribution does install the .enc files in your
       perl directory, but not the.xml files they were created from. That's why you have to specify $ENCDIR as
       in the SYNOPSIS.

       This implementation uses the XML::Encoding class to parse the .xml file and creates a hash that maps
       UTF-8 characters (each consisting of up to 4 bytes) to their equivalent byte sequence in the specified
       encoding.  Note that large mappings may consume a lot of memory!

       Future implementations may parse the .enc files directly, or do the conversions entirely in XS (i.e. C
       code.)

get_encode (Encoding => STRING, EncodeUnmapped => SUB)

       The central entry point to this module is the XML::UM::get_encode() method.  It forwards the call to the
       global $XML::UM::FACTORY, which is defined as an instance of XML::UM::SlowMapperFactory by default.
       Override this variable to plug in your own mapper factory.

       The XML::UM::SlowMapperFactory creates an instance of XML::UM::SlowMapper (and caches it for subsequent
       use) that reads in the .xml encoding file and creates a hash that maps UTF-8 characters to encoded
       characters.

       The get_encode() method of XML::UM::SlowMapper is called, finally, which generates an anonimous
       subroutine that uses the hash to convert multi-character UTF-8 blocks to the proper encoding.

dispose_encoding ($encoding_name)

       Call this to free the memory used by the SlowMapper for a specific encoding.  Note that in order to free
       the big conversion hash, the user should no longer have references to the subroutines generated by
       get_encode().

       The parameters to the get_encode() method (defined as name/value pairs) are:

       •   Encoding

           The name of the desired encoding, e.g. 'ISO-8859-2'

       •   EncodeUnmapped (Default: \&XML::UM::encode_unmapped_dec)

           Defines how Unicode characters not found in the mapping file (of the specified encoding) are printed.
           By default, they are converted to decimal entity references, like '{'

           Use \&XML::UM::encode_unmapped_hex for hexadecimal constants, like '«'

CAVEATS

       I'm not exactly sure about which Unicode characters in the range (0 .. 127) should be mapped to
       themselves. See comments in XML/UM.pm near %DEFAULT_ASCII_MAPPINGS.

       The encodings that expat supports by default are currently not supported, (e.g. UTF-16, ISO-8859-1),
       because there are no .enc files available for these encodings.  This module needs some more work. If you
       have the time, please help!

AUTHOR

       Original Author is Enno Derksen.

       Send bug reports, hints, tips, suggestions to T.J Mather at <tjmather@tjmather.com>.