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xdoclet2 update: Autogenerating AS3 Value Objects from Java (and AS2 too)

April 14, 2006 on 1:06 pm | In Flex, Programming |

Late last year I contributed an xdoclet2 plugin that allows ActionScript value objects to be directly generated from Java source code.

I’ve recently updated the plugin to support the latest Flex Enterprise and AS3 features. The plugin will:

• convert JavaBeans with accessor methods to simple ActionScript value objects with public var properties. The new int type is supported in AS3.
• generate appropriate Object.registerClass() or [RemoteClass] preambles.
• convert public static final constants from Java to public static const in ActionScript.
• for AS3 only, generate [Bindable] and/or [Managed] metadata tags.

The currently downloadable xdoclet-plugins 1.0.3 distribution was cut by the xdoclet2 maintainers before Flex Enterprise Server settled down, so I’ve built an updated Actionscript Plugin that supports the new FES2 metadata correctly. Download it here and use it as a replacement for xdoclet-plugin-actionscript-1.0.3.jar in the xdoclet2 1.0.3 distro.

Some tips on use…

The General Idea

For AS3, all you do is start with a JavaBean and annotate it a little bit. For example,

package com.example;

/**
 * Example of a JavaBean with tags
 * to generate the associated BeanInfo class.
 *
 * @actionscript.class
 *     managed=true
 */
public class SimpleBean {
    /** A String field. */
    protected String baseName = "";

    public String getBaseName() {
        return baseName;
    }

    public void setBaseName(String name) {
        this.baseName = baseName;
    }
}

You’ll wind up generating something like this:

package com.example
{

  import com.example.SimpleBean;

  /** Example of a JavaBean with tags
   to generate the associated BeanInfo class. */

  [Managed]
  [RemoteClass(alias="com.example.SimpleBean")]

  public class SimpleBean
  {
    public var baseName:String;
  }
}

Tagging Java Classes for AS Generation

All you need to do is include an @actionscript.class or @actionscript.property javadoc tag in the class comment or getter-method comment. This tells the generation plugin what to do.

Support for [Bindable] and [Managed]

After an @actionscript.class or @actionscript.property javadoc tag, add either bindable=true or managed=true to generate the corresponding AS3 metadata tags at the class or property level respectively.

Running with Ant

The xdoclet2 site documentation is not the greatest. My friend Ilya Devèrs recently struggled with getting Ant to run the plugin, and kindly sent me back the scripts he used to do it. Here’s a somewhat bastardized version that illustrates the general approach to using the plugin.

Understanding Errors

Look for a velocity.log file located in the directory where you ran Ant. That will probably help.