grails322-plugin-issue

Samples to show how subtly plugin generation toggles between plain jar output and a Boot repackaged jar. Originally I thought this was a problem in Grails 3.2.2, but that's not the case. Grails 3.1.11 behaves the same way.

This issue has no relationship to Grails 2.

Directories

• ping: An app with a dependency to the pong plugin
• pong: A plugin with a taglib used by the ping app

Usage

The following text describes how to build and run the app with its plugin. Two test cases are described. They may be run in any order.

Setup

You are supposed to setup a Grails environment to use the selected Grails version. Everything is run in development environment.

The top directory contains a bash script setup.sh for picking versions of Java, Grails and Gradle. However, it is adapted to the author's system and most likely does not work for you. It is intended to be sourced into the shell where you run the tests.

Either modify it to suit your needs, or follow your own conventions.

Test Run 1

Build and install the pong plugin to your local Maven cache.

cd pong
gradle clean install

Build and run the ping app.

cd ping
grails
grails> clean
grails> run-app

• Browse to the running app
• Under Available Controllers, click ping.PingController
• Click New Ping
• Fill in Say Hi with an arbitrary string and click Create
• Watch the show view

During startup you should see output on standard out from the pong plugin that shows it is being loaded.

The show view should essentially echo your input.

The point of this test run is that the plugin jar is generated, loaded and works as expected.

Test Run 2

Build and install the pong plugin to your local Maven cache. Notice the slightly different gradle command.

cd pong
gradle clean build install

Build and run the ping app.

cd ping
grails
grails> clean
grails> run-app

• Browse to the running app
• Under Available Controllers, click ping.PingController
• Click New Ping
• Fill in Say Hi with an arbitrary string and click Create
• Watch the show view

The behaviour is different:

• No output on standard out during startup
• The show view does not echo your input

The reason is that the pong plugin is never loaded. It is discarded because it was generated as a Boot repackaged jar. There is a WARN log message during startup, but you won't see it without changing log levels in the logging configuration.