Daisuke Maki > Data-Decode-0.00007_01 > Data::Decode



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Data::Decode - Pluggable Data Decoder


  # simple usage (you probably won't use this form much)
  use Data::Decode qw( Encode::Guess );

  my $decoder = Data::Decode->new(
    decoder => Data::Decode::Encode::Gues->new()

  # cascading several decoders
  use Data::Decode
    qw( HTTP::Response Encode::Guess );

  my $decoder = Data::Decode->new(
    decoder => [

  my $res = LWP::UserAgent->new->get("http://whatever.example.com");

  my $decoded = $decoder->decode($res->content, { response => $res });


Data::Decode implements a pluggable "decoder". The main aim is to provide a uniform interface to decode a given data while allowing the actual algorithm being used to be changed depending on your needs..

For now this is aimed at decoding miscellaneous text to perl's internal unicode encoding, but should be able to handle anything if you give it a proper plugin


Japanese, which is the language that I mainly deal with, has an annoying property: It can come in at least 4 different flavors (utf-8, shift-jis, euc-jp and iso-2022-jp). Even worse, vendors may have more vendor-specific symbols, such as the pictograms in mobile phones.

Ways to decode these strings into unicode varies between each environment and application.

Many modules require that the strings be normalized to unicode, but they all handle this normalization process differently, which is, well, not exactly an optimal solution.

Data::Decode provides a uniform interface to this problem, and a few common ways decoding is handled. The actual decoding strategies are separated out from the surface interface, so other users who find a particular strategy to decode strings can then upload their way to CPAN, and everyone can benefit from it.


Data::Decode comes with a simple chaining functionality. You can take as many decoders as you want, and you can stack them on top of each other. To enable this feature, just provide an array as the decoder, instead of a single object.



Instantiates a new Data::Decode object.


Required. Takes in the object that encapsulates the actual decoding logic.

(WARNING: Subject to change - we may require an object that implements a role instead of just a function in the future. Beware!) The object must have a method named "decode", which takes in a reference to the Data::Decode object and a string to be decoded. An optional third parameter may be provided to specify any hints that could be used to figure out what to do.

  # a decode() method
  sub decode {
    my ($self, $decoder, $string, $hints) = @_;
    # $decoder = Data::Decode object
    # $string  = a scalar to be decoded
    # $hints   = a hashref of hints

You may also specify the class names of the decoders -- in that case, an argument-less new() will be called upon the class name to instantiate the decoder.

If you provide a list of decoders, Data::Decode::Chain will automatically be set for you.

  my $decoder = Data::Decode->new(
    decoder => [  # This will turn into a Data::Decode::Chain object


Decodes a string. Takes in a string, and a hashref of hints to be used for decoding. The meaning or the usage of the hints may differ between the actual underlying decoders.


Get the underlying decoder object.


Daisuke Maki <daisuke@endeworks.jp>


This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

See http://www.perl.com/perl/misc/Artistic.html

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