Tapestry-4.1.6 maven archetype

There’s an updated archetype for Tapestry-4.1.6-SNAPSHOT over at (the well known snapshot repo)

All the hard work was done by Ulrich Stärk, so big thanks to him

For the record, here’s how to quickly generate a Tapestry project

mvn archetype:create -DarchetypeGroupId=org.apache.tapestry \
 -DarchetypeArtifactId=tapestry-archetype \
 -DarchetypeVersion=4.1.6-SNAPSHOT -DgroupId=org.example -DartifactId=myapp \

Using Groovy for Tacos-Demo & Tapestry

So, since groovy compiles down to bytecode, it can be used anywhere… That’s how i did a test tapestry page a month ago.

But this time i took some time off to play with groovy and the tacos demo app (Shing is hosting it for us right now) and the JetGroovy plugin of IntelliJ Idea 7.0M2. My findings are really nothing new and mostly deal with java vs. groovy … things!

So, the ajax tree demo uses a TreeData bean for its data… here it is in java:

 public class TreeData {
  private String name;
     private List<TreeData> children;
     public TreeData() {this(null);}
     public TreeData(String name) {
         this.name = name;
         children = new ArrayList<TreeData> ();
     public String getName() { return name; }
     public void setName(String name) { this.name = name; }
     public List getChildren() { return children; }
     public void setChildren(List<TreeData> children) { this.children = children; }
     public void addChild(TreeData value) {
         String name = value.getName();
         for (int i = 0; i < children.size(); i++) {
             TreeData treeData = children.get(i);
             if (name.compareTo(treeData.getName()) < 0) {
                 children.add(i, value);
     public TreeData getOrCreateChild(String value) {
         for (TreeData treeData : children) {
             if (treeData.getName().equals(value))
                 return treeData;
         TreeData data = new TreeData(value);
         return data;

and here it is in groovy:

 class TreeDataGroovy {
     String name
     List<TreeDataGroovy> children
     def addChild(TreeDataGroovy value) {
         if (children==null) children = [];
         int pos = children.findIndexOf { value.name < it.name }
         children.add(pos, value)
     TreeDataGroovy getOrCreateChild(String value) {
         TreeDataGroovy data = children.find {it.name==value};
         if (data==null) {
             data = new TreeDataGroovy(name:value)
         return data;

On the other hand, I ended up dealing with exceptions and errors quite more often that i do in java (perhaps due to my lack of knowledge for groovy) so it did force me in more unit tests, which some say is a good thing and others the opposite.

Tacos 4.1.0 released

Here’s the announcement:

Hi all,
It’s a pleasure for me to announce the release of Tacos 4.1.0
(http://tacos.sourceforge.net/tacos4.1/) – the first stable tacos
release supporting Tapestry 4.1.x and offering:
  • Dojo Widget – Generic component for (almost) all dojo widgets.

  • script.aculo.us – brand new components based on script.aculo.us

  • Comet component

  • New Annotations – allow you to inject ILinks and easily check if
    component parameters are bound.

  • New binding prefixes – including ‘template’ that makes string
    related ognl expressions easier, and ‘absoluteAsset’ which works like
    the asset binding but makes sure that the created url is absolute.

  • BeanForm – All-in-one, flexible bean editor BeanForm has become a
    major part of Tacos. This update offers complete compatibility with
    Tapestry 4.1.2.

  • Tapdoc – though not yet properly released from within tacos, it
    offers a maven plugin for component reference generation.


  • The jars have already been deployed over at ibiblio.org – more
    installation instructions can be found at

  • Beanform (http://beanform.sourceforge.net/) and Tapdoc
    (http://www.erinors.com/developer/project/tapdoc/) have merged
    with Tacos.

  • Huge thanks to our latest committer Igor Drobiazko whose excitement
    has shed new life to the project.

  • Extra special thanks to all the people that contributed code, esp.
    Daniel Gredler, Norbert Sandor, Patrick Moore, Ming Jiang and Craig Spry

Have fun with it!

Tacos 4.0.1 and Tapestry Support for Netbeans 5.5

We had two tapestry-related releases today:

Tacos 4.0.1

Tacos 4.0.1 was released a few hours ago.  
It’s mainly a stability release fixing 2 subtle bugs and  
enhancing the ajax encoder (for very pretty and short ajax urls). 
Make sure to also check out the previously undocumented but powerful 
ajax-enabled Table component. 
Thanks to all that contributed… 

* Docs for tacos:Table component. 
* Load external js synchronously. Fixes Bug127. 
* AjaxSubmit posts all the AjaxLinkSubmits before it. Fixes Bug130. 
* Do not clear current document after error (a failed ajax-post). 
* Jdk1.4 compatible class format for maven generated artifacts. 
* Add StringToListConverter. Allows updateComponents parameter to be specified as a comma-delimited String. 

* Add uniqueNames parameter in AjaxForm – forces the html name of each input control to stem from the component’s idPath (instead of the component’s id). 
* Support validators and translator in HtmlArea. Fixes Bug128. 
* Make buttons in tacos:Palette work. Fixes Bug129. 
* Remove hardcoded class attribute from tacos:Table. 
* Easier way for defining ajax exception and stale-session pages. 
* Enhance AjaxDirectServiceEncoder for ever prettier ajax urls.  

* Corrected links to tapestry’s component docs. 


Just released the first version of nbtapestrysupport.

It provides:

  • Hyperlink support in Tapestry configuration files for class names, files and libraries… CTRL+click everywhere!!!
  • Autocomplete in Tapestry configuration files for class names, files and others
  • Templates for new Tapestry files

Download the 2 nbms, then install the generic module first and then the tapestry module.


Implementing a Firefox Plugin for Tapestry’s Reset Service

Implementing a Firefox Plugin for Tapestry’s Reset Service
Actually, i decided to make this a greasemonkey script, instead of a full FF plugin…

So, here’s the process:

  • 12:25. Install greasemonkey. ( http://greasemonkey.mozdev.org/ )
  • 12:27 Restart Firefox
  • 12:28 Search for a good tutorial on writing greasemonkey scripts.
  • 12:32 Hmm, http://greasemonkey.mozdev.org/authoring.html is a starting point, as is the http://mozdev.elliptic.fr/greasemonkey/linkify.user.js example.
  • 12:33 Create a file named tapestry.user.js somewhere. Open it up in an editor and also in FF. Make your changes in the editor, refresh in FF and click on install to use it.
  • 12:37 After the first hello world examples, let’s create something that adds an absolute positioned div in the current page, containing a static link for the moment.
  • 12:41 I used document.createElement(‘div’) to create the div and document.getElementsByTagName(“body”)[0].appendChild(resetDiv) to add it in the dom.
  • 12:44 I can write links in the div… with the ugly way (hope Jesse isn’t reading this), i.e. resetDiv.innerHTML='<a href=”…”>Cool</a>’
  • 12:45 location.href gives us the current url. we’ll have to hack it a bit to contruct a valid Tapestry reset url. For now, we’ll keep the url from the beggining to the last occurance of slash ‘/’ and append app?service=reset&page=Home afterwards.
  • 12:50 Done! Here’s the result.

Remember to configure the script so that it’s active only on the pages you want. Further updates might:

  • Recognize Tapestry sites and auto-enable the plugin.
  • Recognize and use the current page so that you won’t get redirected to Home.
  • Use better styling for the added div… It should be on the top of the page, with absolute positioning and semi-transparent.
  • See if this also works in Tapestry 3.

So, watch out for an update on this!

P.S.1 You have to enable Tapestry’s reset service for this to work.
P.S.2 If you’re wondering why you need this, then read on : )

While editing Tapestry’s templates (*.html) or configuration files (*.page, *.jwc, *.application, *.library) you can get instant save-refresh functionality if you disable cache (that’s org.apache.tapestry.disable-caching ). This however slows down request handling by a noticable amount and results in memory leaks because classloaders are thrown away on each request. I generally wouldn’t mind about this since it’s only used on development and it takes a LOT of refreshes before one gets an OutOfMemoryException.

But if you’re on AJAX ( read tacos or tapestry 4.1 ) then you’ll get that exception a lot more faster. So, in the last few months I’ve got into the habit of enabling cache + enabling the reset service ( that’s org.apache.tapestry.enable-reset-service. I usually keep an extra tab open in Firefox (having the url of the reset service) and whenever I make changes I hit refresh on that tab (so that all templates and Tapestry configurations are reloaded) and then return to my normal tab.

P.S.3 This was initially written in my internal TiddlyWiki, an awesome javascript-only wiki. I was really surprised when Howard recently commited (!!!) this wiki in Tapestry 5 trunk. In fact, I never knew a wiki could get itself committed! Well done Jeremy.

Tapestry in press – Beginning POJOs

Tapestry in press – Beginning POJOs

I recently came across
Beginning POJOs: Lightweight Java Web Development Using Plain Old Java Objects in Spring, Hibernate, and Tapestry. From the reviews i’ve found, it looked like a nice book and since it does contain a whole chapter on Tapestry, I thought it would be nice to add it in Tapestry‘s site.

So, in order to fill in some (Tapestry related) descriptions, I contacted the author, Brian Sam-Bodden, requesting a detailed table of contents for that chapter. I was pleasantly surprised with Brian’s reply: a 2MB email containing all 70 pages of that chapter – and all this so that I can write a few lines of description… Wow, thanks Brian!

Anyway, the Tapestry chapter is quite interesting, covering Tapestry 4.0.x versions. It starts by describing installation and configuration of the framework, then goes on to explain the concept of pages and components. Several form components are shown and then we learn how to configure and use Hivemind services, tie them to EJB3 services and make use of Application State Objects. Of course, Tapestry annotations are in the mix as well… The chapter ends with more than a dozen pages on AJAX and Tacos. Examples include dynamic user input validation and autocompleters.

Heck, had this book been written 2 months later, it would have also had my name in the tacos section : )

Tapestry: Building Trees with Tacos and Annotations

So, what’s it like using annotations in Tapestry along with complex, cool and ajaxified components?
Well, let’s find out!

Html Template

Assuming that we want our html template to be as clean as possible, our CategoryTree.html file will
look like this:

 <body jwcid="@Border" title="Tree Management">
   <div id="note" >
     <h2>Tree Management</h2>
       <a jwcid="expandAllLink" href="#">Expand All</a> |
       <a jwcid="collapseAllLink" href="#">Collapse All</a>
     <div id="treeArea">
 		<div jwcid="tree" id="tree" style="overflow: auto; width: auto; height: auto;">
 	        <a jwcid="nodeLink" href="folder.png">
 	            <img jwcid="icon" align="absbottom"/>
 	            <span jwcid="nodeLabel">Node 1</span>

This includes 2 links to expand and collapse all nodes and the tree component. Tacos tree component
can be thought of as a smart iteration component (think of For or ForeEach) but it also knows in which
order the (visible) nodes should be rendered and it knows the node depth of each one of them.

So, here’s how the template looks like if you directly preview it in a browser
and here how it looks when tapestry renders it

Page Class

Ok, now let’s move on to the only other file needed, the CategoryTree.java (we would need a
CategoryTree.jwc if we didn’t use annotations). Here it is:

 public abstract class CategoryTree extends BaseCmsPage
 	public abstract CategoryService getCategoryService();
 	public abstract EvenOdd getEvenOdd(); 
 	@InitialValue("new java.util.HashSet()")
 	public abstract Set getTreeState();
 	public abstract Category getNodeToEdit();
 	public abstract void setNodeToEdit(Category node);
 	@Component(type="tacos:Tree", bindings={"contentProvider=contentProvider",
 			"keyProvider=keyProvider", "state=treeState", "value=current", "rowStyle=bean:evenOdd"} )
 	public abstract Tree getTree();
 	@Component(type="DirectLink", bindings={"listener=listener:editNode",
 			"parameters={current.id, current.name}"} )
 	public abstract DirectLink getNodeLink();
 	@Component(type="DirectLink", bindings={"listener=listener:collapseAll"} )
 	public abstract DirectLink getCollapseAllLink();	
 	@Component(type="DirectLink", bindings={"listener=listener:expandAll"} )
 	public abstract DirectLink getExpandAllLink();	
 	@Component(type="Insert", bindings={"value=current.langName",
 			"class=(nodeToEdit!=null and current.id == nodeToEdit.id) ? 'selected' : null"} )
 	public abstract Insert getNodeLabel();
 	public abstract Category getCurrent();
 	public IKeyProvider getKeyProvider() {
 		return new CategoryKeyProvider();
 	public ITreeContentProvider getContentProvider() {
 		return new CategoryTreeContentProvider(getCategoryService());
 	public void editNode(String id, String name) {
 		setNodeToEdit(new Category(id, name, null, null));
 	public void collapseAll() {
 	public void expandAll() {
     public ITreeManager getTreeManager() {
         return new TreeManager(getTreeState(), getContentProvider(), getKeyProvider());

Ok, so I lied (a bit). You still need a few extra classes to run this (i.e. your domain model)
but that’s obvious! Here, we make use of Category (our bean), CategoryService (our way of
finding Categories) and trivial implementations of IKeyProvider and ITreeContentProvider
(the tree’s way of accessing data).

Annotations Used

Now, from top to bottom, here are the annotations explained:

  1. @InjectObject: Inject the specified object-service in our class, simple and powerful. Services
    are defined using Hivemind or Spring -the one used here is a singleton.
  2. @Bean: Create (and inject) a simple javabean. The bean is constructed on each render. We use this
    to achieve alternate coloring of each tree’s node.
  3. @Persist: Store / remembers the value of the property across multiple renders. Uses session by default.
  4. @InitialValue: We don’t want that property to be null at the beggining, and we’re lazy to write java
    code to do this, so we simply add this annotation.
  5. @Component: This one defines the components that are used in this page. In 4.1.1+ versions of Tapestry
    the type attribute can be deduced by the framework if it matched the return type of the annotated method.
    The id of each component is not specified since the framework uses by default the related property name,
    i.e. getNodeLink() is for id nodeLink. This leaves us with the bindings attribute which i find quite
    easy to follow.

From then on, the code contains 6 more methods, all one-liners! Notice how easy it is to collapse or
expand all nodes, and how we add a specific style to the selected node (tip: see the bindings of
getNodeLabel() and the editNode() method).

Ajax Included???

Oh, and BTW, the tree you’ve just created is AJAX enabled! Clicking to expand or collapse a node will
result in only the tree refreshing. You’ll have to add a “nodeLinkAjax=false” to have normal, old-style
refreshes (http://tacos.sourceforge.net/components/Tree.html).

Hope you liked this annotations and tree tour! I’ll soon get back with some entries on Tapestry 4.1.1
new goodies. Always have fun!