Groovy
Metaprograming with Groovy
Check out @ilopmar's talk at confoo2016 to learn about Groovy's metaprogramming capabilities (metaClass, Extension Modules, Categories, Traits...)
For me it is specially awesome the example about MOP (Meta Object Protocol) method synthesis.
Check out the Github repo with the code examples
Use Builder AST Transformation for Fluent API
Internally at @shoptimix, I worked in the last month in a couple of classes to create APNS and GCM payloads to send push notifications to our app. I code them with a (hand made) fluent API. Such an API suits well the use case of such classes.
Unfortunately I wrote them before I discover the @Builder AST transform, developed by @MGrzejszczak and @paulk_asert. This transform makes easy to create Fluent API as @mrhaki illustrates in this post.
Grails
Set Log Level for Grails Artifacts
By default if you install a fresh Grails 3 app and try to log something with log.info you will not see anything. This is probably one of the reasons why so many println statements make it into Grails app. It is not complicated to configure the log levels to suit your needs. We just need to understand the Grails convention.
@mrhaki (explainer-in-chief) explains in a succinct and clear way.
Automatically run test suites and coverage reports for open-source grails projects using Travis CI and coveralls
Everyone seems to be using Travis CI. Specially for open source Github projects, where Travis CI is free. @AseemBansal2 shows how to use the continuous integration system for your Grails projects.
Gradle
Create a Standalone Gradle plugin for Android
Great step-by-step post by @aftercho which shows how to create a gradle plugin from scratch, install it in your local repository and use it your Android build.
Tools
Betamax - Record & replay HTTP traffic
@Betamaxtest is a tool, written in Groovy, for mocking external HTTP resources such as web services and REST APIs in your tests. First time you contact a third party REST api, it saves the response and the next test run will replay the previously saved response. It works with Spock, thus is a perfect tool for a Grails 3 app. Moreover, It seems a like a perfect tool for some of my company tests which relay in third party calls.
They link to a github repo with a Grails example; although the link is currently broken.
Grails keeps full steam ahead with several releases in the past weeks. Moreover Groovy Android project is getting a great momentum and the 0.3.8 release is out.
The next links will sharpen your Groovy skills, help you configure better your Grails projects and probably introduce you to a new project for your toolbelt.
Groovy Calamari