Everyone,
As discussed separately on this list and now included in WICKET-5640
<https://issues.apache.org/jira/browse/WICKET-5640>, I prefer Wicket not
to modify my HTML using its assumptions of how I want to handle e.g. how
a component should look when it is disabled. It turns out that
WICKET-4904 <https://issues.apache.org/jira/browse/WICKET-4904> has
already turned off automatic generation of <em><span> wrapping of
disabled links for Wicket 7.x, which is a great start.
The Yahoo! Pure CSS library, as one example, requires that I use the
pure-button-disabled CSS class for my disabled links. I in no way desire
to include knowledge of third-party libraries in the Wicket framework
itself, but I want to make Wicket easy to support them. So I have
created a simple DisabledClassAttributeAppender class. Using the Yahoo!
Pure CSS as an example, here is all I have to do for my links:
myLink.add(new DisabledClassAttributeAppender("pure-button-disabled"));
It works like a dream! I will contribute this class, and hope it gets
included in an upcoming Wicket version.
But the question remains of how I indicate this for all my links. I
don't want to manually add a DisabledClassAttributeAppender to each link
I create. Moreover, I do /not/ think it appropriate to subclass all my
links (e.g. YahooPureBookmarkablePageLink); that would put too much
knowledge of my CSS framework into my code base, tightly coupling my
styling to my code. (ugh)
I propose the creation of a class named BehaviorBundle. It would
implement IComponentInstantiationListener, and allow essentially a
mapping between component types and behaviors. When a component is
instantiated, the BehaviorBundle would check the type (appropriately
recognizing subclasses) and add the specified behaviors. Here is an
example of how it would work in MyApplication.onInit():
BehaviorBundle yahooPureCSSBehaviorBundle=new BehaviorBundle();
behaviorBundle.addBehavior(AbstractLink.class, new
DisabledClassAttributeAppender("pure-button-disabled"));
//other behaviors for the Yahoo! Pure CSS library
getComponentInitializationListeners().add(yahooPureCSSBehaviorBundle);
That's all! Suddenly all my links would Do The Right Thing for the
Yahoo! Pure CSS library. If I later switched to another library such as
Bootstrap, I would simply switch to another BehaviorBundle and be done
with it! Plus it's more declarative than the old
getMarkupSettings().setDefaultBeforeDisabledLink(...), which had me
embedding HTML in the code, and which was specific to certain elements.
The approach I am proposing allows one to encapsulate a whole series of
behaviors and component associations within one "bundle". Future
versions of Wicket (or third parties) could even offer per-framework
modules, so that developers wouldn't have to roll their own. The
BehaviorBundle class itself would be extremely simple, as the
IComponentInstantiationListener is already in place. This solution I
believe is in the spirit of the Wicket architecture, yet brings
capabilities that Wicket doesn't currently support (to my knowledge).
Any thoughts? I'm going to write this class for our current project
anyway, and I'd be happy if everyone likes the idea, so that I could
contribute it for Wicket 7.x.
Cheers,
Garret
