Grails is an Open Source, full stack, web application framework for the JVM. It takes advantage of the Groovy programming language and convention over configuration to provide a productive and stream-lined development experience. Below diagram depicts the high level Grails Architecture:
GrailsUnitTestCase and GroovyTestCase both extend JUnit 3.x TestCase.MVC Unit Test case will extend GrailsUNitTest case and delegate the test case control to ControllerUnitTestCase and TagLibUnitTestCase
Grails Service uses to separate your business logic from the other layer or component. Services are named in the format SomeNameService.groovy and placed in the directory /grails-app/services/. Services can make use of dependency injection features, and you can easily call these services from within controllers. Continue reading
Grails uses GSP for the presentation tier. The Groovy in Groovy Server Pages not only identifies the underlying technology, but also the language you can use if you want to write a quick scriptlet or two. Groovy Taglib and partial templates give you a more sophisticated way of sharing code and behavior across Web pages. Continue reading
Controllers and views round out the “Big Three” in Grails applications. The Model/View/Controller (MVC) pattern is undoubtedly familiar to most web developers. By enforcing a clean separation of concerns among these three elements, your efforts are paid back in terms of maximum flexibility and reuse. Continue reading
Need to follow below steps for Grails environment setup
- Install JDK1.5 or higher from oracle
- Point the JAVA_HOME environment variable at your JDK installation.
- Download the latest release of Grails from http://grails.org/Download.
- Unzip Grails
- Create a GRAILS_HOME environment variable
- Add GRAILS_HOME/bin to the PATH
Grails is a web framework based on Groovy and Java which can be deployed into existing Java web servers, e.g. Tomcat or Jetty. Its scaffolding capabilities let you create a new project within a few minutes. Grails is based on the “convention over configuration” idea which allows the application to auto-wires itself based on naming schemes (instead of using configuration files, e.gl XML files). Continue reading
Groovy lets the programmer decide to catch the exception or not. In the following example, the developer tries to open and read the contents of a file. He does not need to surround the method with a try and catch block, when he knows that the file exists. Continue reading
The use of semicolons ( ; ) in Groovy is completely optional . The only time a semicolon has to be used, is when multiple function calls are placed on the same line Continue reading