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Monday, August 28, 2006

Tapestry 5 Progress: Class Reloading

Hit one of my first major hurdles for Tapestry 5 this morning: class reloading. Tapestry 5 periodically scans .class files to see if they have changed, and will clear caches and discard class loaders so that it can process the changes. I've finally gotten the code base to a point where I can demonstrate this and it works. And it's fast!

This is a huge productivity win: you change your classes and see the changes immediately. No restart, no redeploy. The same logic works for templates and other resources (you make the change, you see the change).

Speed is excellent; obviously, I have only a tiny fraction of Tapestry 5 implemented, and the page I'm using is very trivial (just a single component). However, even on my laptop, and with all debugging output enabled, refresh is instant.

By the way, here's my page template:

<html xmlns:t="http://tapestry.apache.org/schema/tapestry_5_0_0.xsd">    
    <head>
        <title>First Tapestry 5 Page</title>
    </head>
    <body> 
        <p>
            This is the <span style="color:green">First Tapestry 5 Page, ever!</span>.
        </p> 
        <p>
            Output from HelloWorld component:  <t:comp id="foo" type="HelloWorld"/>                
        </p>
    </body>`
</html>

And here's the HelloWorld component:

package org.apache.tapestry.integration.app1.components;

import org.apache.tapestry.MarkupWriter;
import org.apache.tapestry.annotations.ComponentClass;
import org.apache.tapestry.annotations.RenderTag;

@ComponentClass
public class HelloWorld
{
    @RenderTag
    void renderMessage(MarkupWriter writer)
    {
        writer.write("I Am HelloWorld");
    }
}

I need to do more experimentation; my environment is Eclipse 3.1.2 + Jetty (4) + JettyLauncher plugin. There's ample opportunity for the servlet container to screw us, in terms of their class loaders getting in the way (not showing file changes). Lots of people seem to use the Sydeo Tomcat plugin as well, so I need to check that.

Sunday, August 20, 2006

Update to tapestry-testng

A new version of tapestry-testng has been upload. The version number (1.0.0-SNAPSHOT) has not changed, but there's some new features:

  • Uses TestNG 5.1, the latest version
  • Supports running tests in parallel

The previous versions of tapestry-testng uses a simple instance variable to store the EasyMock control. This is insufficient for TestNG, which creates a single instance of a test case class, and then will invoke test methods on it from multiple threads. This new vesion of the library stores the EasyMock control in a thread local variable.

However, I'm still not 100% certain this will work properly due to how TestNG operates ... it doesn't seem to invoke cleanup methods from the correct thread. See this forum posting. If TestNG is, in fact, broken, then we'll have to wait for a TestNG 5.2 that fixes the issue.

Thursday, August 03, 2006

New version of tapestry-testng

I quietly released a nearly-final version of tapestry-testng a couple of days ago. The new version number is 1.0.0-SNAPSHOT.

The only significant change is that I changed the TestBase base class to extend from org.testng.Assert, so you can access all the assertion methods without doing a static import.