L.S.,
We're using wicket heavily here with quite satisfaction. However in one of
our attempts to setup integrated testing we found that one particular piece of
wicket code isn't quite extendible enough for our needs, which is the
generation of markup ids by the wicket session class.
Since we think that the ability to extend this functionality is not limited to
our use case, I'd like to propose a small change. The patch for this is at
the end of this mail.
The issue is the following; when a Component has no explicit markup-id set,
the markup id is generated by the Session which has an internal counter and
uses an increment of this to generate a mark-id. The flaw IMHO is that a
Component requests the Session to generate an id, without passing it any
context. Especially the most logical context, i.e. "please session, generate
a markup id for _ME_" is missing. Therefore I'd propose that the
Session.getMarkupId() is passes the Component object for which the markup id
is to be generated.
By default, the operation should remain as is and the Session object falls
back to the default getMarkupId() without parameters, which is already
overrideable. But now you can override the getMarkupId() and generate more
useful markup ids.
In our case, we are able to generate markup ids which contain part of the
hierarchy and in this manner generate stable Ids, namely those which do not
change after several requests. This particular usage may just work for our
case (one page application, no back-button support, etc), but the fundamental
overrideable method to generate more useful IDs is more widely applicable,
hence my change request.
If you look at the patch, its a little bit more than just the new method,
that's because the patch is fashioned in such a way that the change is 100%
compatible with previous workings of wicket in casu markup ids. Also, the
getMarkupId used to return just an integer, while a string as return value is
a more useful return value in a more context aware environment. To be sure
the behavior is completely non-intrusive and compatible there is a little bit
of glue coded needed.
I can go into the details of the patch more, but this mail is too long as it
is.
Hope you accept this change,
With kind regards,
Berry van Halderen
--- cut here ---
Index: jdk-1.4/wicket/src/main/java/org/apache/wicket/Session.java
===================================================================
*** jdk-1.4/wicket/src/main/java/org/apache/wicket/Session.java (revision
724306)
--- jdk-1.4/wicket/src/main/java/org/apache/wicket/Session.java (working copy)
***************
*** 1475,1478 ****
--- 1475,1489 ----
{
return sequence++;
}
+
+ /**
+ * Retrieves the next available session-unique value for the supplied
Component
+ *
+ * @param component
+ * the component which requests the generation of a markup
identifier
+ * @return session-unique value
+ */
+ public Object getMarkupId(Component component) {
+ return new Integer(nextSequenceValue());
+ }
}
Index: jdk-1.4/wicket/src/main/java/org/apache/wicket/Component.java
===================================================================
*** jdk-1.4/wicket/src/main/java/org/apache/wicket/Component.java
(revision 724306)
--- jdk-1.4/wicket/src/main/java/org/apache/wicket/Component.java
(working copy)
***************
*** 1426,1437 ****
return null;
}
! final int generatedMarkupId = storedMarkupId instanceof Integer
! ? ((Integer)storedMarkupId).intValue() :
Session.get().nextSequenceValue();
!
! if (storedMarkupId == null)
! {
! setMarkupIdImpl(new Integer(generatedMarkupId));
}
// try to read from markup
--- 1426,1445 ----
return null;
}
! String markupIdPostfix;
! if (!(storedMarkupId instanceof Integer)) {
! Object markupIdFromSession =
Session.get().getMarkupId(this);
! if (storedMarkupId == null && markupIdFromSession !=
null) {
! setMarkupIdImpl(markupIdFromSession);
! }
! storedMarkupId = markupIdFromSession;
! }
! if (storedMarkupId instanceof Integer) {
! markupIdPostfix = Integer.toHexString(((Integer)
storedMarkupId).intValue()).toLowerCase();
! } else if (storedMarkupId instanceof String) {
! return (String) storedMarkupId;
! } else {
! markupIdPostfix = storedMarkupId.toString();
}
// try to read from markup
***************
*** 1449,1455 ****
markupIdPrefix = getId();
}
- String markupIdPostfix =
Integer.toHexString(generatedMarkupId).toLowerCase();
markupIdPostfix =
RequestContext.get().encodeMarkupId(markupIdPostfix);
String markupId = markupIdPrefix + markupIdPostfix;
--- 1457,1462 ----
--- cut here ---
--
Berry A.W. van Halderen [email protected] / [email protected]
Disclaimer: the above is the author's personal opinion and is not the opinion
or policy of his employer or of the little green men that have been following
him all day.
