2.0.0-alpha1

PHP

• Raised minimum PHP version to 5.5.

HTTP

• BC break: Replaced hard coupling on Guzzle HTTP client with HTTPlug.
  You now need to explicitly specify a supported HTTP adapter in composer.json;
  see installation instructions.
• BC break: Separated the HttpDispatcher from the proxy clients. All
  existing clients still use HTTP to send invalidation requests.
• Added support and documentation for setting a custom TTL specifically for the
  caching proxy.

Logging

• BC break: Renamed the log event listener from LogSubscriber to
  LogListener.

Tagging

• BC break: Moved tag invalidation to CacheInvalidator, and renamed
  TagHandler to ResponseTagger.
• Abstracting tags by adding new TagsInterface for ProxyClients.
• Added strict option to ResponseTagger that throws an exception when empty
  tags are added. By default, empty tags are ignored.

Varnish

• Varnish configuration are now files that you can directly include from your
  .vcl and call custom functions to avoid copy-pasting VCL code.
• Added support for and changed default to Varnish version 5.
• Moved Varnish 4 and 5 configuration files from resources/config/varnish-4/
  to resources/config/varnish/.
• Changed default Varnish version to 5.
• Removed special case for anonymous users in user context behaviour. Varnish
  now does a hash lookup for anonymous users as well.

NGINX

• The NGINX purge location is no longer passed as constructor argument but by
  calling setPurgeLocation().

Symfony HttpCache

• BC break: Renamed all event listeners to XxListener instead of
  XxSubscriber.
• BC break: Constructors for PurgeListener and RefreshListener now use
  an options array for customization.
• BC break: Converted abstract event dispatching kernel class
  EventDispatchingHttpCache to a trait, which now provides the addSubscriber
  and addListener methods. In your AppCache, replace
  AppCache extends EventDispatchingHttpInterface with a
  use EventDispatchingHttpCache; statement.
• The user context by default does not use a hardcoded hash for anonymous users
  but does a hash lookup. You can still configure a hardcoded hash.

Testing

• BC break: Refactored the proxy client test system into traits. Removed
  ProxyTestCase; use the traits CacheAssertions and HttpCaller instead.
• Added HTTP method parameter to HttpCaller::getResponse().