oracular (3) Badger::Codecs.3pm.gz
NAME
Badger::Codecs - modules for encoding and decoding data
SYNOPSIS
# using class methods
use Badger::Codecs;
$encoded = Badger::Codecs->encode( base64 => $original );
$decoded = Badger::Codecs->decode( base64 => $encoded );
# creating a single codec object
$codec = Badger::Codecs->codec('base64');
$encoded = $codec->encode($original);
$decoded = $codec->decode($encoded);
# creating a codecs collection
$codecs = Badger::Codecs->new(
base => ['My::Codec', 'Badger::Codec'],
codecs => {
# most codec names are grokked automatigally from the
# base defined above - this hash is for any exceptions
wibble => 'Ferret::Codec::Wibble',
frusset => 'Stoat::Codec::Frusset',
}
);
# encode/decode via codecs collective
$encoded = $codecs->encode( wibble => $original );
$decoded = $codecs->decode( wibble => $encoded );
# or via a specific codec
$codec = $codecs->codec('wibble');
$encoded = $codec->encode($original);
$decoded = $codec->decode($encoded);
# importing a single codec
use Badger::Codecs
codec => 'url';
# codec() returns a Badger::Codec::URL object
$encoded = codec->encode($text);
$decoded = codec->decode($encoded);
# encode() and decode() are imported subroutines
$encoded = encode($text);
$decoded = decode($encoded);
# import multiple codecs
use Badger::Codecs
codecs => 'base64 storable';
# codec objects
base64->encode(...); base64->decode(...);
storable->encode(...); storable->decode(...);
# imported subroutines
encode_base64(...); decode_base64(...);
encode_storable(...); decode_storable(...);
# import a codec chain
use Badger::Codecs
codec => 'storable+base64';
# as before, now both codecs are applied
codec->encode(...);
codec->decode(...);
encode(...);
decode(...)
# multiple codecs with various options
use Badger::Codecs
codecs => {
link => 'url+html',
str64 => 'storable+base64',
};
# codec objects
link->encode(...); link->decode(...);
str64->encode(...); str64->decode(...);
# subroutines
encode_link(...); decode_link(...);
encode_str64(...); decode_str64(...);
# accessing codecs via Badger::Class
use Badger::Class
codec => 'base64';
codec(); encode(...); decode(...);
use Badger::Class
codecs => 'base64 storable';
base64(); encode_base64(...); decode_base64(...);
storable(); encode_storable(...); decode_storable(...);
DESCRIPTION
A codec is an object responsible for encoding and decoding data. This module implements a codec manager
to locate, load and instantiate codec objects.
Using Codecs
First you need to load the "Badger::Codecs" module.
use Badger::Codecs;
It can be used in regular OO style by first creating a "Badger::Codecs" object and then calling methods
on it.
my $codecs = Badger::Codecs->new();
my $codec = $codecs->codec('url');
my $encoded = $codec->encode($original);
my $decoded = $codec->decode($encoded);
You can also call class methods directly.
my $codec = Badger::Codecs->codec('url');
my $encoded = $codec->encode($original);
my $decoded = $codec->decode($encoded);
Or like this:
my $encoded = Badger::Codecs->encode(url => $original);
my $decoded = Badger::Codecs->decode(url => $encoded);
These examples are the equivalent of:
use Badger::Codec::URL;
my $codec = Badger::Codec::URL->new;
my $encoded = $codec->encode($original);
my $decoded = $codec->decode($encoded);
"Badger::Codecs" will do its best to locate and load the correct codec module for you. It defines a
module base path (containing "Badger::Codec" and "BadgerX::Codec" by default) to which the name of the
requested codec is appended in various forms.
It first tries the name exactly as specified. If no corresponding codec module is found then it tries a
capitalised version of the name, followed by an upper case version of the name. So if you ask for a
"foo" codec, then you'll get back a "Badger::Codec::foo", "Badger::Codec::Foo", "Badger::Codec::FOO" or
an error will be thrown if none of these can be found.
NOTE: the above paragaph is incorrect. It now tries the capitalised version first to work around Apple's
case-insensitive file system. This is subject to change.
my $codec = Badger::Codecs->code('url');
# tries: Badger::Codec + url = Badger::Codec::url # Nope
# tries: Badger::Codec + Url = Badger::Codec::Url # Nope
# tries: Badger::Codec + URL = Badger::Codec::URL # Yay!
Chained Codecs
Codecs can be chained together in sequence. Specify the names of the individual codes separated by "+"
characters. Whitespace between the names and "+" is optional. The codec chain returned
(Badger::Codec::Chain) behaves exactly like any other codec. The only difference being that it is apply
several codecs in sequence.
my $codec = Badger::Codecs->codec('storable+base64');
$encoded = $codec->encode($data); # encode storable then base64
$decoded = $codec->decode($encoded); # decode base64 then storable
Note that the decoding process for a chain happens in reverse order to ensure that a round trip between
encode() and decode() returns the original unencoded data.
Import Hooks
The "codec" and "codecs" import hooks can be used to load and define codec subroutines into another
module.
package My::Module;
use Badger::Codecs
codec => 'base64';
The "codec" import hook defines a "codec()" subroutine which returns a reference to a codec object. It
also defined "encode()" and "decode()" subroutines which are mapped to the codec.
# using the codec reference
$encoded = codec->encode($original);
$decoded = codec->decode($encoded);
# using the encode/decode subs
$encoded = encode($original);
$decoded = decode($encoded);
The "codecs" import hook allows you to define several codecs at once. A subroutine is generated to
reference each codec, along with encoding and decoding subroutines.
use Badger::Codecs
codecs => 'base64 storable';
# codec objects
$encoded = base64->encode($original);
$decoded = base64->decode($encoded);
$encoded = storable->encode($original);
$decoded = storable->decode($encoded);
# imported subroutines
$encoded = encode_base64($original);
$decoded = decode_base64($encoded);
$encoded = encode_storable($original);
$decoded = decode_storable($encoded);
You can define alternate names for codecs by providing a reference to a hash array.
use Badger::Codecs
codecs => {
text => 'base64',
data => 'storable+base64',
};
# codec objects
$encoded = text->encode($original);
$decoded = text->decode($encoded);
$encoded = data->encode($original);
$decoded = data->decode($encoded);
# imported subroutines
$encoded = encode_text($original);
$decoded = decode_text($encoded);
$encoded = encode_data($original);
$decoded = decode_data($encoded);
IMPORTABLE SUBROUTINES
Codec()
This subroutine can be used as a shortcut to the codec method.
use Badger::Codecs 'Codec';
my $yaml = Codec('YAML');
print $yaml->encode($some_data);
METHODS
new()
Constructor method to create a new "Badger::Codecs" object.
my $codecs = Badger::Codecs->new();
my $encoded = $codecs->encode( url => $source );
See "CONFIGURATION OPTIONS" for details of the configuration options that can be specified.
base(@modules)
The base() method can be used to set the base module path. It can be called as an object or class
method.
# object method
my $codecs = Badger::Codecs->new;
$codecs->base('My::Codec');
$codecs->encode( Foo => $data ); # My::Codec::Foo
# class method
Badger::Codecs->base('My::Codec');
Badger::Codecs->encode( Foo => $data ); # My::Codec::Foo
Multiple items can be specified as a list of arguments or by reference to a list.
$codecs->base('Ferret::Codec', 'Stoat::Codec');
$codecs->base(['Ferret::Codec', 'Stoat::Codec']);
codecs(\%new_codecs)
The codecs() method can be used to add specific codec mappings to the internal "codecs" lookup table. It
can be called as an object method or a class method.
# object method
$codecs->codecs(
wam => 'Ferret::Codec::Wam',
bam => 'Stoat::Codec::Bam',
);
my $codec = $codecs->codec('wam'); # Ferret::Codec::Wam
# class method
Badger::Codecs->codecs(
wam => 'Ferret::Codec::Wam',
bam => 'Stoat::Codec::Bam',
);
my $codec = Badger::Codecs->codec('bam'); # Stoat::Codec::Bam
codec($type, %config)
Creates and returns a "Badger::Codec" object for the specified $type. Any additional arguments are
forwarded to the codec's constructor method.
my $codec = Badger::Codecs->codec('storable');
my $encoded = $codec->encode($original);
my $decoded = $codec->decode($encoded);
If the named codec cannot be found then an error is thrown.
chain($type, %config)
Creates a new Badger::Codec::Chain object to represent a chain of codecs.
encode($type, $data)
All-in-one method for encoding data via a particular codec.
# class method
Badger::Codecs->encode( url => $source );
# object method
my $codecs = Badger::Codecs->new();
$codecs->encode( url => $source );
decode($type, $data)
All-in-one method for decoding data via a particular codec.
# class method
Badger::Codecs->decode( url => $encoded );
# object method
my $codecs = Badger::Codecs->new();
$codecs->decode( url => $encoded );
export_codec($package,$name,$alias)
Loads a single codec identified by $name and exports the "codec", "encode" and "decode" functions into
the $package namespace.
package Your::Module;
use Badger::Codecs;
Badger::Codecs->export_code('Your::Module', 'base64');
# base64() returns the codec
base64->encode($data);
base64->decode($data)
# encode() and decode() are shortcuts
encode($data)
decode($data);
An $alias can be provided which will be used instead of "codec" and appended to the names of the "encode"
and "decode" functions.
package Your::Module;
use Badger::Codecs;
Badger::Codecs->export_codec('Your::Module', 'base64', 'munger');
# munged() returns the codec
munger->encode($data);
munger->decode($data)
# encode_munger() and decode_munger() are shortcuts
encode_munger($data)
decode_munger($data);
export_codecs($package,$names)
Loads and exports multiple codecs into $package. The codec $names can be specified as a a string of
whitespace delimited codec names, a reference to a list of codec names, or a reference to a hash array
mapping codec names to aliases (see export_codec()).
Badger::Codecs->export_codecs('Your::Module', 'base64 storable');
Badger::Codecs->export_codecs('Your::Module', ['base64', 'storable']);
Badger::Codecs->export_codecs('Your::Module', {
base64 => 'alias_for_base64',
storable => 'alias_for_storage',
});
load($name)
Loads a codec module identified by the $name argument. Returns the name of the module implementing the
codec.
print Badger::Codecs->load('base64'); # Badger::Codec::Base64
found($name,$codec)
This is an internal method called by the base class Badger::Factory module when a codec is located and
loaded.
found_object($name,$codec)
This is an internal method called by the base class Badger::Factory module when a cached codec object is
found.
result($name,$codec,\@args)
This is an internal method called by the base class Badger::Factory module to return a final result for
the requested code. This method caches the codec object if no configuration arguments were provided.
CONFIGURATION OPTIONS
path
This option can be used to specify the name(s) of one or more modules which define a search path for
codec modules. The default path contains "Badger::Codec" and "BadgerX::Codec".
my $codecs = Badger::Codecs->new(
path => 'My::Codec'
);
my $codec = $codecs->codec('Foo'); # My::Codec::Foo
Multiple paths can be specified using a reference to a list.
my $codecs = Badger::Codecs->new(
path => ['My::Codec', 'Badger::Codec'],
);
my $codec = $codecs->codec('Bar'); # either My::Codec::Bar
# or Badger::Codec::Bar
codecs
The "codecs" configuration option can be used to define specific codec mappings to bypass the automagical
name grokking mechanism.
my $codecs = Badger::Codecs->new(
codecs => {
foo => 'Ferret::Codec::Foo',
bar => 'Stoat::Codec::Bar',
},
);
my $codec = $codecs->codec('foo'); # Ferret::Codec::Foo
AUTHOR
Andy Wardley <http://wardley.org/>
COPYRIGHT
Copyright (C) 2005-2009 Andy Wardley. All rights reserved.
This module is free software; you can redistribute it and/or modify it under the same terms as Perl
itself.