README

A cache-aware HTTP2 Server Push implementation, for the Laravel framework

For a comprehensive study of the impacts of HTTP2 Push, check out this article, courtesy of Merj Ltd

HTTP2 Push is hard! This package makes it easy, providing a simple blade directive that informs clients "Hey, I know you've only asked for a HTML document, but I already know you'll need this stylesheet, so just start downloading them now".

Resources are pushed once per cached-lifetime.

i.e, say you have a stylesheet with a cache length set via the Cache-Control header, with an expiry length of 28 days. The package will initially push the resource, and also set a cookie to track (per resource) whether it has been sent, and therefore cached - after all, there's no need to push a resource that the browser has already cached (Hence the motivation behind this package).

Installation

Install the package via composer:

composer require tomkeyte/laravel-http2-push

Publish the configuration (recommended):

php artisan vendor:publish --provider="TomKeyte\LaravelHttp2Push\Http2PushServiceProvider"

Server config

IMPORTANT! HTTP2 Push via the Link header must be enabled for your webserver

Instructions for nginx and apache.

Usage

Check the http2push.php config file to set default expiry lengths based on your setup. N.B, expiry lengths throughout the package are expressed in days - a value of -1 indicates no cookie should be set, resulting in a push on all requests.

The setup is as following:

• Set the global cookie expiry limit with cookie_expires_in
• Set the cookie expiry for certain file types (these override the global limit):

'cookie_expire_types' => [
    'font' => 90,
    'script' => 27,
    'style' => 24,
    'image' => 30,
],

• Optionally, supply an array of resources that should be pushed on every request*

'always' => [
    '/js/app.js', # A simple string
    [
        'src' => '/css/app.css', # Or an array, containing the src & expiry time
        'expires' => '90',
    ],
],

In your blade templates, push the resources:

// use default cookie expiry lengths
@h2push('/css/app.css')

// specify a cookie expiry length of 60 days, for this resource only
@h2push('/js/app.js', 60)

It is recommended you version your resources, so that the package can track whether it needs to re-push them. This package works well with laravel-mix

@h2push( mix('/css/app.css') )

* Every GET request that is routed through the web middleware

Testing

composer test

Generate a code coverage report with

composer test-coverage

Requires an applicable code coverage driver, such as xdebug

Credits

• Tom Keyte
• Merj Ltd

License

The MIT License (MIT). Please see License File for more information.