Re: [TM4J-users] NullPointer in TM4JVelocityApp.pushContext

[Kal A. <ka...@te...>]

On Mon, 2004-10-11 at 18:57, Christoph Froehlich wrote:
> Hi Kal
> 
> thanks for the quick fix. It works now...  until I reach
> 
> org.tm4j.topicmap.utils.extractors.AssociationGroupsExtractor$DefaultAssociationGroupComparator.compare(AssociationGroupsExtractor.java:149)
> 
> where another NullPointer waits. I fixed this one myself and could
> either commit the fix or send you a patch, just as you prefer.
> 
Feel free to commit the fix - I guess that it is probably an untyped
association or untyped role case that I didn't catch in the code.

> Beside of this last NPE, batch.xml now runs successfully and produces a
> lot of html files.
> 
> Unfortunately there is one more problem with the default skin.
> The "topicref"-macro in "utils.vm" constantly produces the following
> loglines: 
> Mon Oct 11 19:39:11 CEST 2004   [warn]
> org.apache.velocity.runtime.exception.ReferenceException: reference :
> template = associations.vm [line 2,column 29] : ${filename.fn($topic)}
> is not a valid reference.
> 
> Therefor all links from index.html to any topic detail page refer to the
> unresolved string "$filename.fn($topic).html".
> 
You need to create the filename object. You can do this by adding the
following line to topicmap.vm:

#set ($filename  =
$factory.create("org.tm4j.vtl.extractors.FileNameExtractor"))

The factory variable should be initialised by the toolbox.xml. Actually
it probably makes sense for FileNameExtractor to implement the Velocity
ViewTool interface so that you can load it in the toolbox.xml. But for
now, add that line to topicmap.vm as a workaround.

> I haven't got deep enough into tm4Web to know where I should start to
> look for the missing reference. Do you have a hint for me?
> 
In general, any variables set by #set in topicmap.vm or setup.vm are
available when processing the whole topic map. Any variables set in
topic.vm or any of the templates it calls are available only for the
processing of that topic.

The toolbox.xml allows you to choose the scope of a variable. If the
<scope> element content is  "request" then the tool is initialised once
for each page generated. If the <scope> element content is application
then the tool is initialised once at the start of processing and the
same instance is available to every page.

Hope this helps!

Cheers,

Kal

-- 
Kal Ahmed <ka...@te...>
techquila