NAME

CatalystX::Fastly::Role::Response - Methods for Fastly integration to Catalyst

SYNOPSIS

package MyApp;

...

use Catalyst qw/
    +CatalystX::Fastly::Role::Response
  /;

extends 'Catalyst';

...

package MyApp::Controller::Root

sub a_page :Path('some_page') {
    my ( $self, $c ) = @_;

    $c->cdn_max_age('10d');
    $c->browser_max_age('1d');

    $c->add_surrogate_key('FOO','WIBBLE');

    $c->response->body( 'Add cache and surrogate key headers' );
}

DESCRIPTION

This role adds methods to set appropriate cache headers in Catalyst responses, relating to use of a Content Distribution Network (CDN) and/or Caching proxy as well as cache settings for HTTP clients (e.g. web browser). It is specifically targeted at Fastly but may also be useful to others.

Values are converted and headers set in finalize_headers. Headers affected are:

• Cache-Control

  HTTP client (e.g. browser) and CDN (if Surrogate-Control not used) cache settings

• Surrogate-Control

  CDN only cache settings

• Surrogate-Key

  CDN only, can then later be used to purge content

• Pragma

  only set for for browser_never_cache

• Expires

  only for browser_never_cache

TIME PERIOD FORMAT

All time periods are expressed as: Xs, Xm, Xh, Xd, XM or Xy, e.g. seconds, minutes, hours, days, months or years, e.g. 3h is three hours.

CDN METHODS

cdn_max_age

$c->cdn_max_age( '1d' );

Used to set max-age in the Surrogate-Control header, which CDN's use to determine how long to cache for. If not supplied the CDN will use the Cache-Control headers value (as set by "browser_max_age").

cdn_stale_while_revalidate

$c->cdn_stale_while_revalidate('1y');

Applied to Surrogate-Control only when "cdn_max_age" is set, this informs the CDN how long to continue serving stale content from cache while it is revalidating in the background.

cdn_stale_if_error

$c->cdn_stale_if_error('1y');

Applied to Surrogate-Control only when "cdn_max_age" is set, this informs the CDN how long to continue serving stale content from cache if there is an error at the origin.

cdn_never_cache

$c->cdn_never_cache(1);

When true the Surrogate-Control header will have a value of private, this forces Fastly (other CDN's may behave differently) to never cache the results (even for multiple outstanding requests), no matter what other options have been set.

BROWSER METHODS

browser_max_age

$c->browser_max_age( '1m' );

Used to set max-age in the Cache-Control header, browsers use this to determine how long to cache for. The CDN will also use this if there is no Surrogate-Control (as set by "cdn_max_age")>.

browser_stale_while_revalidate

$c->browser_stale_while_revalidate('1y');

Applied to Cache-Control only when "browser_max_age" is set, this informs the browser how long to continue serving stale content from cache while it is revalidating from the CDN.

browser_stale_if_error

$c->browser_stale_if_error('1y');

Applied to Cache-Control only when "browser_max_age" is set, this informs the browser how long to continue serving stale content from cache if there is an error at the CDN.

browser_never_cache

$c->browser_never_cache(1);

When true the headers below are set, this forces the browser to never cache the results. private is NOT added as this would also affect the CDN even if cdn_max_age was set.

Cache-Control: no-cache, no-store, must-revalidate, max-age=0, max-stale=0, post-check=0, pre-check=0
Pragma: no-cache
Expires: 0

N.b. Some versions of IE won't let you download files, such as a PDF if it is not allowed to cache it, it is recommended to set a "browser_max_age"('1m') in this situation.

IE8 have issues with the above and using the back button, and need an additional Vary: * header, as noted by Fastly, this is left for you to implement.

SURROGATE KEYS

add_surrogate_key

$c->add_surrogate_key('FOO','WIBBLE');

This can be called multiple times, the values will be set as the Surrogate-Key header as `FOO WIBBLE`.

See "cdn_purge_now" in MooseX::Fastly::Role if you are interested in purging these keys!

INTERNAL METHODS

finalize_headers

The method that actually sets all the headers, should be called automatically by Catalyst.

SEE ALSO

MooseX::Fastly::Role - provides cdn_purge_now and access to Net::Fastly stale-while-validate

BUGS

Please report any bugs or feature requests on the bugtracker website https://github.com/metacpan/p5-CatalystX-Fastly-Role-Response/issues

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.

AUTHOR

Leo Lapworth

CONTRIBUTORS

• Graham Knop haarg@haarg.org
• Leo Lapworth leo@cuckoo.org

COPYRIGHT AND LICENSE

This software is copyright (c) 2016 by Leo Lapworth.

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