Monday June 04, 2007
NetBeans Visual Web Pack - Real World Apps Tip #1 - Dynamic Content
I promised I would start blogging about my experiences developing the
NetBeans
Plugin Portal when I gave my BOF at JavaOne this year.
So this blog is the start of that series. To get
some background on the project, you really should look through
my
slides for the BOF.
There seemed to be the most interest around building a "Tag Cloud"
using NetBeans VWP (Visual Web Pack). So I thought I would
start with that topic. In order to do tag clouds in VWP, you
need to understand how to create two things first, dynamic content and
dynamic hyperlinks. This blog will cover the details of
creating dynamic content with NetBeans VWP. I'll then follow
up with blogs for dynamic hyperlinks and finally tag clouds.
I do plan to put the source code for the Plugin Portal out on
netbeans.org soon but I have to get through another phase and do some
cleanup first. In order to demonstrate these topics, I'll be
building simplified projects to be downloaded.
First, what is "
Dynamic
Content"? My use of this term focuses on the
distinction between the design time UI design and the run time UI.
Content that can not be visually created during design time
is content that I refer to as "
Dynamic
Content" or content that is created during run time.
Representing the Content in the Design Time
One of the greatest features of using VWP is the visual designer.
The designer gives you a pretty good idea what the page will
look like at runtime. So obviously you'd like to use the
designer to even help with the dynamic content. To do this,
use a "Layout Panel" as a placeholder for the dynamic content.
Here's a screenshot of the project we will build.
You can see the outline of the "Layout Panel" which I named
"dynamicPanel".
Creating the Content at Run Time
Now that you have a placeholder for the dynamic content,
"dynamicPanel", you can create the content at run time. We'll
target the "preprocess" method of the page backing bean. For
more information on the VWP application model, please see the article, "
The
Java Studio Creator 2 Application Model". As you
may already know, VWP incorporates most of the Java Studio Creator 2
functionality. The application model in VWP is the same as Java Studio
Creator 2.
For this first example, let's simply add a button as dynamic content.
Here's the code to do that.
public void prerender() {
/**
* First clear out the layout panel
*/
if(null != dynamicPanel.getChildren()) {
dynamicPanel.getChildren().clear();
}
/**
* Now create the button to add.
*/
Button dynamicButton = new Button();
dynamicButton.setText("My Button");
/**
* Add the button to the layout panel.
*/
dynamicPanel.getChildren().add(dynamicButton);
}
Note 1 - If you don't know the type for the component you want to add,
visually add the component to the designer and look at the Java source
to find the type.
Note 2 - The content you add MUST be a subtype of "UIComponent".
Conclusion
Here's what our page will look like.
Now that I have covered the basics of creating dynamic content, in my
next blog I'll cover creating dynamic hyperlinks.
You can download the
sample
"DynamicContent" project I used to get started. I
used NetBeans 5.5 with Visual Web Pack installed to create the project.
Posted by David Botterill
( Jun 04 2007, 01:19:48 PM MDT )
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