NAME

MooX::Role::CachedURL - a role providing a locally cached copy of a remote file

SYNOPSIS

 package MyClass;
 use Moo;
 with 'MooX::Role::CachedURL';
 has '+url' => (default => sub { 'http://www.cpan.org/robots.txt' });
 
 sub my_method {
    my $self = shift;
    my $fh   = $self->open_file;
 
    while (<$fh>) {
        ...
    }
    $self->close_file($fh);
 }

Then in the user of MyClass:

 use MyClass;
 my $object = MyClass->new(max_age => '2 days');
  
 print "local file is ", $object->cache_path, "\n";

DESCRIPTION

This role represents a remote file that you want to cache locally, and then process. This is common functionality that I'm pulling out of my PAUSE::Users, PAUSE::Permissions and PAUSE::Packages modules.

PAUSE::Users provides a simple interface to the 00whois.xml file that is generated by PAUSE. It caches the file locally, then provides a mechanism for iterating over all users in the file.

ATTRIBUTES

cache_path

The full path to the local file where the content of the remote URL will be cached. You can provide your own path, but if you don't, then an appropriate path for your operating system will be generated.

path

A full or relative path to your own copy of the cached content. If you provide this, then your content will be used, without checking the remote URL. If the file you pass doesn't exist, the module will croak().

url

This specifies the URL that should be cached locally. It should be over-ridden in the composing class, as shown in the SYNOPSIS above.

max_age

Specifies the maximum age of the local copy, in seconds. We won't even look for a new remote copy if the cached copy is younger than this.

You can specify max_age using any of the notations supported by Time::Duration::Parse. For example:

 max_age => '2 hours',

Support for gzip'd files

If the cache_path or path attribute ends in .gz, then the file is assumed to be gzip'd, and will be transparently handled using PerlIO::gzip.

TODO

• Switch to LWP for general URL handling, not just HTTP

• Ability for a class to transform content when caching

REPOSITORY

https://github.com/neilbowers/MooX-Role-CachedURL

AUTHOR

Neil Bowers <neilb@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2014 by Neil Bowers <neilb@cpan.org>.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

cpanm MooX::Role::CachedURL

perl -MCPAN -e shell
install MooX::Role::CachedURL