Javascript ids are session unique anyway - just prefixed with the component id in non-deployment config.

Sven

On 03/30/2012 04:11 PM, Juergen Donnerstag wrote:
On Fri, Mar 30, 2012 at 3:57 PM, Sven Meier<s...@meiers.net>  wrote:
Hi Juergen and Jesse,

I've debugged WicketLinkTagHandler and everything worked as I have expected
it:

The WicketTag is always the same instance, coming from the cached markup.
Changing its id doesn't make sense to me: This is global state which is
accessed for *each* rendering of the container.


An id which is unique with markup file is not guranteed to be unique in the
page markup.
That's why resolvers are using the page.autoIndex to create a page unique
id
Yes, the id has to be unique for components inside their container. That
hasn't changed with the patch.

 From a component resolution point of view you are right, but I think
you are ignoring Javascript here. wicket-ids may become become ids and
they need to be page unique, correct?

Juergen

Back to debugging
Sven



On 03/30/2012 12:40 PM, Juergen Donnerstag wrote:
On Fri, Mar 30, 2012 at 3:01 AM, Jesse Long<je...@virtualpostman.co.za>
  wrote:
Hi Juergen, Sven,

We are not doing away with adding the "auto index" unique number to the
resultant component id, we are only doing away with modifying the id in
the
cached markup tag.
The patched changed the resolver and not the filter. Hence the markup
loaded into the cache is still the same, but the id presented at
render time is now a different.

The uniqueness of the id of the component returned by the resolve()
method
is still being guaranteed (as far as I understand) because it takes the
original id from the tag and append the current page's next auto index
number. The component (TransparentWebMarkupContainer) is then created
with
this modified id.
sorry but this is also not correct. The markup of a page is composed
of potentially many markup files (fragments, panels, inheritance,
etc.). An id which is unique with markup file is not guranteed to be
unique in the page markup. That's why resolvers are using the
page.autoIndex to create a page unique id

All I'm asking in this patch is to not modify the original id stored in
the
markup tag, because its not necessary. (AFAIK).

Anyway, the resultant component id is now (after the patch) as unique as
it
is on the first render without the patch...
sorry, but this is not true.

This problem is actually very serious. I have a base page which 90% of my
pages extend. Without the patch, on every single render, the id stored in
the tag has a few bytes appended, causing the id of the resultant
component
to be a few bytes longer (for every render of every page in any session).
I'm not sure if these ids get stored in memory after the render (I dont
know
wicket internals well enough to tell) or stored in the page store. If
they
do, its a big memory leak.

At the very least its spews out huge amounts of data in the debug
logging.
I very well understand your pain point, but lets fix the problem
properly and not introduce a bug with an enhancement.

Juergen

Cheers,
Jesse



On 29/03/2012 22:39, Sven Meier wrote:
Hi,

An artifical markup which creates duplicate IDs can be constructed.
all auto labels' tags have the same id already (its class name) so no
need
to create some artificial markup.

To me the applied patch leaves us with a bigger problem than it fixes.
If the id of the tag in the cached markup is altered on each render, the
id can get quite long pretty fast. As the reporter of the issues has
stated,
this is a 'big' problem ;).

we should fix it properly
Agreed. Obviously I'm missing a key concept here.
I'll try to debug this issue tomorrow to understand the problem you've
identified.

Sven

On 03/29/2012 09:44 PM, Juergen Donnerstag wrote:
Hi Sven

I double checked with how other filters/resolvers are doing it and I
found
AutoLabelTextResolver to leave the tag id untouched too.
which is a fault as well. Same risk.

May be a Component's flag bit can be used for that purpose.
Shouldn't that be a flag on the markup tag instead then?
No, because the Pages are made of potentially many markups. Since the
ID has no info about hierarchy, the number appended is the only thing
that makes it page unique. Hence it can not be per markup. Since every
tag gets associated with a Component, the Component is the right place
for the flag.

I don't know how likely it is and I know we have no tests for it.
Yeah, I didn't find one either. I'm not sure I understand where's a
possible
problem here. It's hard to discuss this issues without an actual case.
An artifical markup which creates duplicate IDs can be constructed.
I've not tried it but I don't expect it to be too difficult. Knowing
there is a potential risk which will be very hard to find by a normal
user, makes me belief we should fix it properly, To me the applied
patch leaves us with a bigger problem than it fixes.

Juergen

Sven


On 03/29/2012 08:42 PM, Juergen Donnerstag wrote:
Hi Sven,

the change introduces a theoretical risk of duplicate ids. I don't
know how likely it is and I know we have no tests for it. But Filters
are created per markup file and modify the markup upon loading, prior
to caching. Which also means that the Page is not available. In case
of inheritance it might not even be the same Page. To be absolutely
sure the ID is page-unique, it gets update in the Resolvers where the
Page instance is available.

The root cause is that we don't validate if the ID has been updated
already and avoid subsequent updates. We have no means to do that
check. A number at the end of the ID would not be sufficient. May be
a
Component's flag bit can be used for that purpose.

I understand the problem in your application, but users will have an
extremly hard time to identify the issue if it occurs. I'm not sure
it's worth it. May be the approach outlined above solved your problem
as well, but in a safe manner.

Juergen

On Thu, Mar 29, 2012 at 6:43 PM,<svenme...@apache.org>        wrote:
Updated Branches:
  refs/heads/wicket-1.5.x c6c45a510 ->        d7e0d8845


WICKET-4484 do not change tag id when resolving component


Project: http://git-wip-us.apache.org/repos/asf/wicket/repo
Commit:
http://git-wip-us.apache.org/repos/asf/wicket/commit/d7e0d884
Tree: http://git-wip-us.apache.org/repos/asf/wicket/tree/d7e0d884
Diff: http://git-wip-us.apache.org/repos/asf/wicket/diff/d7e0d884

Branch: refs/heads/wicket-1.5.x
Commit: d7e0d8845dd509110e48ba965f0e11a3aae6a1f5
Parents: c6c45a5
Author: Sven Meier<svenme...@apache.org>
Authored: Thu Mar 29 18:43:07 2012 +0200
Committer: Sven Meier<svenme...@apache.org>
Committed: Thu Mar 29 18:43:07 2012 +0200


----------------------------------------------------------------------
  .../markup/parser/filter/WicketLinkTagHandler.java |    1 -
  1 files changed, 0 insertions(+), 1 deletions(-)

----------------------------------------------------------------------





http://git-wip-us.apache.org/repos/asf/wicket/blob/d7e0d884/wicket-core/src/main/java/org/apache/wicket/markup/parser/filter/WicketLinkTagHandler.java

----------------------------------------------------------------------
diff --git


a/wicket-core/src/main/java/org/apache/wicket/markup/parser/filter/WicketLinkTagHandler.java


b/wicket-core/src/main/java/org/apache/wicket/markup/parser/filter/WicketLinkTagHandler.java
index 689133e..8779b6f 100644
---


a/wicket-core/src/main/java/org/apache/wicket/markup/parser/filter/WicketLinkTagHandler.java
+++


b/wicket-core/src/main/java/org/apache/wicket/markup/parser/filter/WicketLinkTagHandler.java
@@ -208,7 +208,6 @@ public class WicketLinkTagHandler extends
AbstractMarkupFilter implements ICompo
                        if (wtag.isLinkTag()&&
  (wtag.getNamespace()
!=
null))
                        {
                                String id = tag.getId() + "-" +
container.getPage().getAutoIndex();
-                               tag.setId(id);

                                return new
TransparentWebMarkupContainer(id);
                        }


Reply via email to