Implementing Tapestry Component Methods with Groovy (Part II)


Richard Hensley was also working on integrating Groovy with Tapestry. He took my groovy-listener code and incorporated it with his own code. We created a project on sourceforge and as christened by Howard we called the project, Groovestry.

The combined codebase is documented at: http://groovestry.sf.net and the source code can be downloaded from http://www.sf.net/projects/groovestry.

The class and package names may have been changed but Groovestry still supports the feature set described in my earlier postin g, with the addition of several features from Richard's original implementation. These include:

Declaration of scripts as component or page beans:

<bean name="miscMethods" lifecycle="page" class="org.apache.tapestry.contrib.script.ScriptBean"> <set-property name="script"> 'MiscMethods' </set-property> </bean>

Which looks for a file MiscMethods.groovy in the same location as the component or page specification.
Methods in these bean-declared scripts can also be bound to listeners in the page:

<à href="Page2.html" jwcid="@DirectLink" listener="ognl:beans.miscMethods.beanTestMethod">Click here</a>

This allows multiple scripts to be used by a page and the same script may be referenced on multiple pages.

Groovy scripts no longer have to be formal classes, the 'def' keyword can be used to define functions in the script
which can be bound as listeners in the page or component. Listener method definitions may declare between 1 and 3 arguments with
the following method signatures:

def listener1(cycle) { } /* * This listener is called with the page and the request cycle. */ def listener2(page, cycle) { } /* * This listener is called with the page, component, and * the request cycle. */ def listener3(page, component, cycle) { }

Scripted classes, particularly those with the same name as the Component or Page behave as I documented earlier and can still be compiled to .class files for deployment if they are added to the package <namespace>.script where namespace is the namespace the component is deployed from, application scripts can be compiled if they are declared with package application.script

The example application has been updated to use the new code, and the source code tree has been modified so that the script-enabling code can be built and deployed as a jar which is used by the sample application.

Thanks to Richard for doing all of the work to integrate the two sets of source code and integrate the test cases.
Posted: Thu - August 5, 2004 at 08:16 AM           |