Groovy Server Pages (GSP) puts the Web in the Grails Web framework. In the third installment of his Mastering Grails series, Scott Davis shows you the ins and outs of working with GSP. See how easy it is to use Grails TagLibs, mix together partial fragments of GSPs, and customize the default templates for the automatically generated (scaffolded) views.

The first two articles in this series introduced you to the basic building blocks of the Grails Web framework. I’ve told you — repeatedly — that Grails is based on the Model-View-Controller (MVC) architectural pattern (see Resources), and that Grails favors convention over configuration for binding the framework’s parts together. Grails uses intuitively named files and directories to replace the older, more error-prone method of manually cataloguing these linkages in an external configuration file. For example, in the first article you saw that controllers have a Controller suffix and are stored in the grails-app/controller directory. In the second article, you learned that domain models can be found in the grails-app/domain directory.

This month, I’ll round out the MVC triptych with a discussion of Grails views. Views (as you might guess) are stored in the grails-app/views directory. But there’s much more to the view story than the intuitively obvious directory name. I’ll talk about Groovy Server Pages (GSP) and give you pointers to many alternative view options. You’ll learn about the standard Grails tag libraries (TagLibs) and find out how easy it is to create your own TagLib. You’ll see how to fight the ongoing battle for DRYness (see Resources) by factoring common fragments of GSP code into their own partial templates. Finally, you’ll learn how to tweak the default templates for scaffolded views, thereby balancing the convenience of automatically created views with the desire to move beyond a Grails application’s default look-and-feel.

– See Original @ DeveloperWorks (Scott Davis)

Tags: Grails, Groovy, Scott Davis