There's more to Ratpack than non-blocking

There’s more to Ratpack than non-blocking

Marcin Erdmann

@marcinerdmann

•  Groovy enthusiast since 2010 •  open source contributor •  Geb lead •  Ratpack committer •  testing junkie •  part of the Energized Work crew

What I won’t talk about

•  Promises •  Execution model – http://tinyurl.com/ratpack-execution-1 – http://tinyurl.com/ratpack-execution-2

•  Handlers •  Handler chains

What I will talk about

•  Development time reloading •  Deploying to the cloud •  Testing •  Configuration •  Application lifecycle •  Renderers and parsers •  Session support

Development time reloading

•  Based on Gradle continuous mode •  Enabled by –t/--continuous switch •  Server restart is performed on change •  Only user classes are reloaded •  Detects any changes in the build

Demo 01-reloading

Deploying to heroku

•  Given: –  JDK – Gradle – Heroku toolbelt

•  In ~7min from zero to deployment •  Heroku’s Gradle example is a ratpack app – heroku/gradle-getting-started on github

ApplicationUnderTest

•  SAM interface that provides app URI •  Has a default method for creating TestHttpClient pointing at the app

•  Default implementations are lazy –  MainClassApplicationUnderTest

–  GroovyRatpackMainApplicationUnderTest

•  CloseableApplicationUnderTest works well with @AutoCleanup

GroovyEmbeddedApp

•  Useful for trying out ideas in the same file as the test

•  Useful for mocking out external http services •  Can be used to integration test classes as part of

a running application - Handlers, Chains, Services, Renderers, Parsers, SessionsStores, etc

Demo 04-embedded-application

Impositions

•  Useful in moulding application under test •  Allow control over configuration and registries •  No need to modify production code •  New in 1.2.0

Configuration

•  Many built in config sources (json, yaml and property files, environment, system properties, command line args)

•  Parsed into a tree of Jackson ObjectNodes •  Mapped into objects that are available

from the registry •  Mapped using Jackson ObjectMapper •  Easily changed at test time via imposition

Custom config sources

•  Create your own config source if needed •  Implement ratpack.config.ConfigSource •  Add using ServerConfigBuilder.add()

•  Useful when overriding config in tests

Demo 06-custom-config

Remote control

•  Useful for gray box testing •  Useful when setting up internal state

before test •  Useful when verification of state would be

tedious if using app’s public interfaces •  Built in support in Ratpack •  Easily enabled in tests via imposition

Renderers

•  Strategy classes for rendering http responses from different objects

•  Used with Context.render(Object) •  Builtin renderers for CharSequence, Path,

json, Promise, Renderable, various templates

•  Add your own by implementing Renderer or extending RendererSupport

Demo 08-renderers

RenderableDecorator

•  Allow to decorate rendered objects •  Sit between Context.render(Object) Renderer.render(Context, Object)

•  Useful for adding default values to template models

•  Add your own by implementing RenderableDecorator or extending RenderableDecoratorSupport

Parsers

•  Strategy classes for parsing http requests into objects

•  Used with Context.parse(Class) •  Builtin renderers for json and http forms •  Add your own by implementing Parser or

extending ParserSupport

Sessions

•  Designed with support for distributed sessions in mind

•  Built-in store implementations: in memory, cookie based, redis backed

•  Build your own – file backed store example in javadoc for SessionStore interface

Sessions

•  By default serialized using Java serialization

•  Customize by implementing SessionSerializer and putting it in the registry

Services

•  Can participate in application lifecycle – onStart(StartEvent) – onStop(StopEvent)

•  Implement ratpack.server.Service

•  Put them in registry

Integrate over abstract

•  ratpack-tymeleaf, ratpack-handlebars vs ratpack-template

•  ratpack-hikari vs ratpack-connection-pool •  ratpack-pac4j vs ratpack-security •  ratpack-dropwizard-metrics,

ratpack-hystrix, ratpack-rx •  registry is abstracted hence Ratpack can be

used with Guice, Spring or none •  good strategy if you’re in for a long run

#unfollowdanveloper

Summary

Questions?