NAME

       LWP::UserAgent::Role::CHICaching - A role to allow LWP::UserAgent to cache with CHI

SYNOPSIS

       Compose it into a class, e.g.

         package LWP::UserAgent::MyCacher;
         use Moo;
         extends 'LWP::UserAgent';
         with 'LWP::UserAgent::Role::CHICaching',
              'LWP::UserAgent::Role::CHICaching::SimpleKeyGen',
              'LWP::UserAgent::Role::CHICaching::SimpleMungeResponse';

DESCRIPTION

       This is a role for creating caching user agents. When the client makes a request to the
       server, sometimes the response should be cached, so that no actual request has to be sent
       at all, or possibly just a request to validate the cache. HTTP 1.1 defines how to do this.
       This role makes it possible to use the very flexible CHI module to manage such a cache.
       See LWP::UserAgent::CHICaching for a finished class you can use.

   Attributes and Methods
       "cache"
           Used to set the "CHI" object to be used as cache in the constructor.

       "request_uri"
           The Request-URI of the request. When set, it will clear the "key", but should probably
           be left to be used internally for now.

       "request"
           Wrapping LWP::UserAgent's request method.

       "is_shared"
           A boolean value to set whether the cache can be shared. The default is that it is.

       "heuristics_opts"
           A hashref that is passed to the "freshness_lifetime" method of HTTP::Response, and
           used to determine the behaviour of the heuristic lifetime. By default, heuristic
           freshness lifetime is off, only standards-compliant freshness lifetime (i.e. based on
           the "Cache-Control" and "Expires" headers) are used.

   Implemented elsewhere
       The following are required by this role, but implemented elsewhere. See
       LWP::UserAgent::Role::CHICaching::SimpleKeyGen and
       LWP::UserAgent::Role::CHICaching::SimpleMungeResponse for further explanations.

       "key", "clear_key"
           The key to use for a response.

       "cache_vary($response)"
           A method that returns true if the response may be cached even if it contains a "Vary"
           header, false otherwise. The HTTP::Response object will be passed to it as a
           parameter.

       "cache_set($response, $expires_in)"
           A method that takes the HTTP::Response from the client and an expires time in seconds
           and set the actual cache.

       "finalize($cached)"
           A method that takes the cached entry as an argument, and will return a HTTP::Response
           to return to the client.

LIMITATIONS

       Will only cache "GET" requests, and only successful responses.

       The module does not validate and does not serve stale responses, even when it would be
       allowed to do so. It nevertheless does most of RFC7234.

BUGS

       Please report any bugs to <https://github.com/kjetilk/p5-lwp-useragent-chicaching/issues>.

AUTHOR

       Kjetil Kjernsmo <kjetilk@cpan.org>.

ACKNOWLEDGEMENTS

       It was really nice looking at the code of LWP::UserAgent::WithCache, when I wrote this.

       Thanks to Matt S. Trout for rewriting this to a Role.

COPYRIGHT AND LICENCE

       This software is copyright (c) 2015, 2016 by Kjetil Kjernsmo.

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