Thursday, March 31, 2005

Creating Tabbed Menus

WARNING: This blog entry was imported from my old blog on (which used different blogging software), so formatting and links may not be correct.

Somebody asked on the forum how to create a Tab menu using standard
JSF components.

Here's one way you can do it. It's not easy (yet!) but works.
The solution involves the following steps:

  • Each tab will have its own unique page
  • The tab component itself is a page fragment. You include
    this fragment on each of the pages that belong in
    the tab arrangment.
  • The tab fragment is simply a grid panel laid out
    horizontally, with a link for each tab.
  • In the navigation file, you use wildcard rules to
    ensure that a hyperlink clicked in the tab fragment on any
    page goes to the corresponding tab page.
  • You use CSS to visually create the "tab" effects. To do
    this, you should have two styleclasses: one for the current
    tab and one for the non-current tabs. Use value binding
    to dynamically choose a styleclass for each cell based
    on whether this tab's page is selected.

First go ahead and create your TabFragment. In it, drop a gridpanel.
Let's say you want 6 pages to be part of this tab. Set the columns
property to 6 - this will ensure that the components are laid out
in a single horizontal row.

Now drop 6 hyperlinks into the page. The tab text
for the nested output text components should be the displayed tab names.
The action properties for the action links should be logical
navigation case names - these can be anything, as long as you use
the same names in your navigation file. (Note that each link action
you dropped results in two separate components - the link, which has
an action property, and a nested output text, which has the text string.
Use the application outline when in doubt.)

Next, go and create all six pages that will be part of the
tabbed set. On each page, include the tab fragment.
Next go to the navigation file, switch to the XML file view
(because wildcards are not yet well supported in the design
view), and add a rule like this - use cut & paste:


This assumes that one of the links in the tabbed fragment
has the action attribute set to "viewPreferences", and when
clicked, this will navigate to the ViewPreferences.jsp page.

Repeat the above for all the hyperlinks in your tabbed fragment
such that each has a page, a corresponding link, and a corresponding
navigation rule.

Voila! You're ready to run - you now have a functional (but ugly)
tabbed window set up. You should be able to run and navigate
the tabs as expected.

The next thing you'll want to do is create some sort of visual
feedback for the tabs, such that exactly one tab is shown as
"current" (e.g. it has a tabbed border). Likewise, you'll probably
want to change the link styling for this tab (so it looks like
plain text) and for the other tabs (so they look less like hyperlinks).

We can achieve this with CSS. Let's say you add these two rules
to your stylesheet:

.selected { }
.notselected { }

We'll tweak these later. Now the big question is: How do we
get the tab fragment to automatically style the different portions
of the tabbed fragments according to which tab is selected?

Go to your tabbed fragment's backing bean, and add some code like this:

// XXX You MUST keep this in sync with the actual links included in the page fragment,
// and navigation destinations in the navigation.xml file!
static String[] tabs = { "/Page1.jsp",

private int getSelectedIndex() {
FacesContext fc = getContext();
String viewId = fc.getViewRoot().getViewId();
for (int i = 0; i < tabs.length; i++) {
if (viewId.equals(tabs[i])) {
return i;

public String getColClasses() {
StringBuffer sb = new StringBuffer();
int sel = getSelectedIndex();
for (int i = 0; i < sel; i++) {
for (int i = sel+1; i < tabs.length; i++) {
return sb.toString();

The whole point of this code is to create a property in the page fragment,
called "colClasses", which will return something like "notselected selected notselected notselected notselected notselected"
if for example the second tab is selected. And how do we know which tab is selected? It's obviously
the page that is including the tabbed fragment being rendered! So the getSelectedIndex()
method goes out and finds out what the root page name is, then looks that up in its
tabbed page list (which you need to edit obviously), and based
on this computes a comma-separated list of style class names.

The list of style class names can be bound directly to the grid panel
in the page fragment which is including the links. Go and select it, then set its
columnClasses property to the value binding expression #{TabFragment.colClasses}.
(You can do this by right clicking on the grid panel and choosing Property Bindings... too,
then drill into your page fragment and locate the colClasses name. Don't forget to hit Apply.)

We're almost done. We now apply different styles to the different cells rendered
for the tabs in the tab fragment. Now we just need to play with CSS to create tab-like effects.

Here are some things you'll want to try:

  • To create a "tab" visual effect, create a single line border on the left, top and right sides -
    but not on the bottom. You can use css like this for that:

    border-left: solid 1px gray
    border-right: solid 1px gray
    border-top: solid 1px gray
    border-bottom: none

  • Use different background colors to the selected and the unselected tabs:

    .selected {
    background-color: #cccccc;
    .notselected {
    background-color: #999999;

  • You'll probably want to turn off hyperlink colors and underlines,
    using "color: black; text-decoration: none" for example,
    and maybe enable hyperlink underlines when the mouse moves over a link, using a rule
    like "a[hover] { text-decoration: underline }

I wish I could share my stylesheet with you but I used an existing proprietary one.
If anyone does work on this and wants to publish their solution feel free to
append a comment!
Good luck and let me know how it works out!

Hippie Completion

WARNING: This blog entry was imported from my old blog on (which used different blogging software), so formatting and links may not be correct.

I read in
Cendric Beaust's blog that
the latest Eclipse snapshot now has "hippie completion".
This is an editor feature where you press a keybinding
and the editor automatically completes the word you're
typing for you, by searching around in your current document
(and if not found) in other documents.

NetBeans has had this feature for at least five years.
Since Creator is built on top of NetBeans, you'll find it in
Creator too.

Hippie completion is also known as hippie expansion and originated
in Emacs. See for example
XEmacs documentation

It is bound to Ctrl-K (and on the Mac, Command-K).
Go ahead and try it - it's the best way to figure out how
it works. If the word you want to complete has many possible
matches, hit Ctrl-K repeatedly to cycle through the matches.
For example, in a typical Creator file, if you type
"Ht" and hit Ctrl-K, it's going to offer HtmlCommandButton,
HtmlOutputText, etc. if you have buttons and text components
on the page. Now aren't you glad you didn't have to
type that?

While I'm on the topic of editor shortcuts, another feature
you may not know about it "Go Back". Let's say you've jumped
around in your editor files, by clicking on error links in
the output window, or by using "Go to declaration" (alt-g if
I remember correctly), etc. You can "Go Back" just like in
a browser by hitting Alt-K. And to move forward again, hit
Alt-L. (And yes, these have toolbar buttons in Creator, and
in recent NetBeans 4.1 builds as well.)

Monday, March 28, 2005

Even the Tooth Fairy Is Too Busy

WARNING: This blog entry was imported from my old blog on (which used different blogging software), so formatting and links may not be correct.

My daughter was pretty disappointed this morning. She lost her front
tooth, and put it in a glass by her bed last night. And this morning,
the tooth fairy had apparently not stopped by - or perhaps she did,
but after taking a look at the tooth decided she didn't want to trade.

The last couple of weeks have been really busy. On the home front,
all three of my kids have been sick, which with all the implied sleepless
nights has really taken its toll on me. But we've had fun too - on Sunday
my youngest son took an unintentional swim in the

Vaillancourt Fountain
in San Francisco. Luckily there was a clothing
store nearby so he didn't have to take the train home in soaking wet

The main reason I've been busy however is work. Those of you using
Creator today will be very happy to see the fruits of our labor in
the next version.

This is my favorite part of the development process. Yes, you have more
freedom in earlier stages too take all kinds of input and plan to
do everyhing. Yes. Yes. Yes.
And a pony too? Sure, no problem.

However, my favorite part is later in the cycle.
All the major systems are getting done, they're getting integrated,
they're working, and it's really exciting to see hard work paying
off. And especially to actually start playing with what will be the
end product.

My favorite quote from the Creator team is "It's all uphill from here!".
I only vaguely remember the context, but I know it was
Joe who said it, so perhaps
he can blog about it. Anyway, the beauty of the quote was that it
was said eloquently and in context such that it meant exactly the opposite
of what it sounds like. But I think it's that inflection point in
development I like best - acceleration. Or maybe even the Big Bang
metaphor. We've had a couple of big bangs lately, with different
people integrating big changes simultaneously, and seeing it all work together is

I'm working from my garage office, but I have
a baby monitor
so I can hear the kids in the house. And they sound asleep. I'd better go
play the Tooth Fairy. I told my daughter this morning the fairy is
probably busy and can't stop by every house every night. But I'd better
take care of it tonight. After all, if she's not writing software, how busy could she be?

Thursday, March 10, 2005

Stylish Components

WARNING: This blog entry was imported from my old blog on (which used different blogging software), so formatting and links may not be correct.

This article
on CSS and Creator was published today.

Wednesday, March 9, 2005

Silence Is Golden!

WARNING: This blog entry was imported from my old blog on (which used different blogging software), so formatting and links may not be correct.

Actually, that's just my excuse for not blogging much the last couple of weeks - and I haven't visited the
forum at all either.

I'm working feverishly on some new features for an internal milestone.

But I promise to come back and post early next week, so be sure to check back!

Oh, a parting tip: Be sure to place Message List components on ALL your pages. If an error is triggered
somewhere in your application, and this is detected in the JavaServer Faces code, it will typically log
an error message. If you don't have a Message List component on your page you won't see the error!

Furthermore, you can use the Message List components for simple "printf" debugging. Whenever you're writing
some code and it's not working - you can just use the debugger (it works, although sometimes requires the server
to be restarted in debugging mode). But a really quick & dirty way to see your results is to just call
the "error" method, which is defined in your page beans' super class. So just do this:

Object o = getValue("#{foo}");
// hmmmm I wonder what type o is?
error("DEBUG: The class of o is " + o.getClass().getName());

When you run, the Message List component will display your message (or set of messages, if more than one was
logged). This even works with multiple pages - let's say you put a Message List on each one of your pages.
If you put an error() call in the action handler for a submit button, then the message you
printed will show up on the new page you navigated to in its own Message List component!

Here's some more info about the Message List and notification mechanism. Be sure to scroll to the top and check out the rest of the article
too. I haven't read it yet (remember, I'm swamped at the moment) but I've glanced enough at it that I can
recommend it!