Dancer2::Plugin::Cache::CHI - Dancer plugin to cache response content (and anything else)


version 2.0.1


In your configuration:

            driver: Memory
            global: 1

In your application:

    use Dancer2;
    use Dancer2::Plugin::Cache::CHI;

    # caching pages' response


    get '/cache_me' => sub {
        cache_page template 'foo';

    # using the helper functions

    get '/clear' => sub {

    put '/stash' => sub {
        cache_set secret_stash => request->body;

    get '/stash' => sub {
        return cache_get 'secret_stash';

    del '/stash' => {
        return cache_remove 'secret_stash';

    # using the cache directly

    get '/something' => sub {
        my $thingy = cache->compute( 'thingy', sub { compute_thingy() } );

        return template 'foo' => { thingy => $thingy };


This plugin provides Dancer2 with an interface to a CHI cache. Also, it includes a mechanism to easily cache the response of routes.


Unrecognized configuration elements are passed directly to the CHI object's constructor. For example, the configuration given in the "SYNOPSIS" will create a cache object equivalent to

    $cache = CHI->new( driver => 'Memory', global => 1, );


If the parameter 'honor_no_cache' is set to true, a request with the http header 'Cache-Control' or 'Pragma' set to 'no-cache' will ignore any content cached via 'cache_page' and will have the page regenerated anew.



Returns the CHI cache object.

cache $namespace, \%args

CHI only allows one namespace per object. But you can create more caches by using cache $namespace, \%args. The new cache uses the arguments as defined in the configuration, which values can be overriden by the optional arguments (which are only used on the first invocation of the namespace).

    get '/memory' => sub {
        cache('elephant')->get( 'stuff' );

    get '/goldfish' => sub {
        cache( 'goldfish' => { expires_in => 300 } )->get( 'stuff' );

Note that all the other keywords (cache_page, cache_set, etc) will still use the main cache object.


If invoked, returns the cached response of a route, if available.

The path_info attribute of the request is used as the key for the route, so the same route requested with different parameters will yield the same cached content. Caveat emptor.

cache_page($content, $expiration)

Caches the $content to be served to subsequent requests. The headers and http status of the response are also cached.

The $expiration parameter is optional.


Returns the cache key used by 'cache_page'. Defaults to to the request's path_info, but can be modified via cache_page_key_generator.

cache_page_key_generator( \&sub )

Sets the function that generates the cache key for cache_page.

For example, to have the key contains both information about the request's hostname and path_info (useful to deal with multi-machine applications):

    cache_page_key_generator sub {
        return join ':', request()->host, request()->path_info;

cache_set, cache_get, cache_remove, cache_clear, cache_compute

Shortcut to the cache's object methods.

    get '/cache/:attr/:value' => sub {
        # equivalent to cache->set( ... );
        cache_set $params->{attr} => $params->{value};

See the CHI documentation for further info on these methods.



Called before the creation of the cache, which is lazily done upon its first use.

Useful, for example, to change the cache's configuration at run time:

    use Sys::Hostname;

    # set the namespace to the current hostname
    hook before_create_cache => sub {
        config->{plugins}{'Cache::CHI'}{namespace} = hostname;


Dancer2 Web Framework - Dancer2


Dancer::Plugin::Memcached - plugin that heavily inspired this one.


Yanick Champoux <>


This software is copyright (c) 2023 by Yanick Champoux.

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