[TM4J-users] Re: [Tm4j-developers] [ tm4j-Bugs-1092125 ] TMAPI "features"

[Lars H. <tm...@qu...>]

Hi George,

I try to answer your bug report here.

> Summary: TMAPI "features"
[...]
>        propsprops.setProperty
> ("http://tmapi.org/features/readOnly",
> "true");
>        mapFeatures.put
> ("http://tmapi.org/features/readOnly", Boolean.TRUE);

>       TMAPITopicMapSystemImpl tmApiSystImpl = new
> TMAPITopicMapSystemImpl
> (providerFactory.getClass().getName(), props, mapFeatures);


This is not the way how you should work with TMAPI. You've to create
an instance of the TopicMapSystemFactory first.

import org.tmapi.core.*;
TopicMapSystem tmSys = null;
TopicMapSystemFactory tmSysFac = TopicMapSystemFactory.newInstance();
try {
    tmSysFac.setFeature("http://tmapi.org/features/readOnly", true);
    tmSys = tmSysFac.newTopicMapSystem();
catch (TMAPIException ex) {
  // Do something useful here.
}

It is a bad thing to use the TMAPITopicMapSystemImpl directly, because
you cannot switch between the underlying topicmap processor and the
one goal of TMAPI goes away.

>         URI uri = ...
>         InputStream is = uri.toURL().openStream ();
>         TopicMap tm = OpenXtmSupport.readXtm (is,
[...]

Here you've switched to the TM4J API again. You should not do it. You
should only use the TMAPI.

IMO the failure that the TopicMapSystem does not throw an
UnsupportedOperationException if you try to change the readOnly
TopicMapSystem instance goes back to the switching between TM4J API
and TMAPI.

You should only use TMAPI interfaces and not work with the wrapped
TM4J objects directly (or if you have to work with them, do it
carefully and only if really necessary).

IMO the bug, that no exception is thrown if the TopicMapSystem is read
only was fixed in 0.98 (Look into the source of the TMAPI objects,
there must be something like a call to "checkIfReadOnly()" or something
like that).

> but still I don't get Exception when I change the TopicMap.
> also I can't merge without TopicName (they merge
> TopicNames)

I'm not sure but I think disabling merging by TopicName is not
supported by TM4J... .

Best regards,
Lars