I was searching for a way to hook business logic after successful user login while using Spring Security Core plugin. The simplest way to do this is to register callback closures. It let's you hook your custom code inside Config.groovy after certain Spring Security events.
This tutorial will show how to integrate payment processing with your Grails application using the Grails Paypal plugin. This plugin provides integration with Paypal's Instant Payment Notfication (IPN) system. Very useful for selling products and services.
Grails Quartz plugin allows to execute scheduled business logic on the background using a specified interval or cron expression. This tutorial will show how to install and use this plugin in your Grails applications.
This tutorial will show how to send email messages from your controllers or services using the Grails mail plugin. The plugin is very easy to use as it could talk to SMTP servers. You can connect to your own mail servers or to other popular mail providers such as Gmail or Yahoo.
This example will show how to generate barcodes using the barcode4j plugin for display in web HTML view and in downloaded PDF. The latter is useful for printing on regular or label printer. This example assumes you are using Grails version 2.x.