Ratpacked: Type Check And Static Compilation For Groovy DSL

One of the very nice features of Ratpack is the Groovy DSL to define our application. We get a nice DSL to set up the registry, to define handlers and more. Because of clever use of the @DelegateTo annotation we get good code completion in our IDE. We can also add static compilation of our Groovy DSL when we start our Ratpack application. With static compilation the script is type checked at compile time so we get earlier feedback on possible errors in the script. To configure static compilation we must invoke the app method of the Groovy.Script class with the argument true.

We start with a Groovy DSL for an application that serves recipes. Notice the Closure arguments are all typed, so with type checking there are no errors.

Next we create a class with a main method that will be the starting point of our application. We need to run this class to start our Ratpack application. The example class is a Java class, but could also be written with Groovy:

When we use the Gradle Ratpack plugin we use this class as the main class:

Now we can still use the run task to start our Ratpack application.

Written with Ratpack 1.4.5.

Original blog post

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About mrhaki

My name is Hubert A. Klein Ikkink also known as mrhaki. I work at the great IT company JDriven. Here I work on projects with Groovy & Grails, Gradle and Spring. At JDriven we focus on SpringSource technologies. All colleagues want to learn new technologies, support craftmanship and are very eager to learn. This is truly a great environment to work in. You can contact me via Google+ or @mrhaki.

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