This document provides an introduction and overview of Grails, a web application framework for Groovy and Java developers. It discusses why Grails is an agile framework, how it integrates various technologies like Groovy, Spring, Hibernate, and more seamlessly. It also demonstrates how to create a basic Grails application with a domain class in under 5 minutes using common Grails commands. Finally, it lists some of the author's open source Grails plugins.

1. Grails 101
Lim Chee Kin
limcheekin@vobject.com
http://limcheekin.blogspot.com

2. About Me
● Moderator of the Malaysia Groovy and Grails User Group
● Involved in Grails development since version 0.6 and
developed 15 Grails plugins to date
● 10+ years experience in software development and
solution consulting for Java EE platform
● Experience spans across various industries, including
retail sector, telecommunication, heath care and
financial services industry.
● Experienced in many frameworks and web technologies,
including Java EE, SpringFramework, Hibernate, Groovy,
Grails Framework, Web Services, JQuery, JQuery UI

3. Why Grails
●
●
● To practice agile development process you
need an agile framework.

4. Inside Grails
● Seamless integration of ...
● Groovy ● Tomcat
● Java ● Ant
● SpringFramework ● Maven
● Hibernate ● Log4J
● Java EE ● H2 Database
● Sitemesh ● Quartz
● JQuery ● ... many more

5. Best Practices Support
● Convention over Configuration standard directory
structure
● Dependency Injection SpringFramework
● Model domain class View GSP Controller groovy class
● Test Automation JUnit, Spock
● Modularization plugin system
● Code Generation scaffolding
● Fast Development Cycle dynamic reloading

6. Running Grails App in 5 minutes
● Step 1: grails create-app addressbook
●
● Step 2: grails create-domain-class Person
●
● Step 3: grails generate-all Person
●
● Step 4: grails run-app

7. Step 1: grails create-app addressbook
● Created Grails Application at /opt/dev/ws/addressbook

8. Step 1: grails create-app addressbook
/addressbook
● application.properties
● grails-app/conf/ --> location of configuration artifacts
● grails-app/conf/hibernate --> optional hibernate config
● grails-app/conf/spring --> optional spring config
● grails-app/controllers/ --> location of controller artifacts
● grails-app/domain/ --> location of domain classes
● grails-app/i18n/ --> location of message bundles for i18n
● grails-app/services/ --> location of services
● grails-app/taglib/ --> location of tag libraries
● grails-app/utils/ --> location of grails specific utility classes
● grails-app/views/ --> location of views
● grails-app/views/layouts --> location of layouts
● lib/ --> jar files not available via installed plugins
● scripts/ --> scripts
● src/groovy --> optional; location for Groovy source files (of types
other than those in grails-app/*)
● src/java --> optional; location for Java source files
● test/ --> test classes
● web-app/ --> css, images, etc, etc, etc.

9. Step 2: grails create-domain-class Person
● Created file grails-app/domain/addressbook/Person.groovy
Created file test/unit/addressbook/PersonTests.groovy
●
● class Person {
● String firstName
● String lastName
● Date dateOfBirth
● Integer age
●
● static constraints = {
● firstName(nullable:true, maxSize:60)
● lastName(nullable:true, maxSize:30)
● dateOfBirth(nullable:true, maxSize:10)
● age(nullable:true)
● }
● }

10. Step 3: grails generate-all Person
● Finished generation for domain class addressbook.Person

11. Step 4: grails run-app
Server running. Browse to http://localhost:8080/addressbook

12. Step 4: grails run-app

13. Step 4: grails run-app

14. My Open Source Grails Plugins
● I contributed 15 Grails plugins out of 826
(13 Aug 2012), including:
● Grails Activiti Plugin
● http://code.google.com/p/grails-activiti-plugin/
● Grails Form Builder Plugin
● http://code.google.com/p/grails-form-builder-plugin/
● JQuery Validation UI Plugin
● http://grails.org/plugin/jquery-validation-ui
● Mahout Recommender Plugin
● https://github.com/limcheekin/mahout-recommender
● Find out more at http://goo.gl/VPVrd

15. Q&A