How to: Programmatically add topic to topicmap (so that it is correct)

[Malte]

Everything seemed to work fine using

topicmapService.addTopicToTopicmap(topicmap.getId(), topic.getId(), null);

.. the "Topicmap" has a "Topic Mapcontext" relation to an added "Topic"

But:

(A) the added topic does not appear in the Topicmap (visually in webclient) - also not if I call tmService.setVisibility(topcmapId, topicId, true);
(B) and an AmbiguityException? ("there are 2 dm4.topicmaps.topic_mapcontext") is thrown which I could not deal with since
(C) I could not find a way to look for existing "Topics" in a "Topicmap" since "TopicmapService?" doesn't offer me "getTopicmapTopics()" (or something equivalent) and

My current workaround for issue (C)

• load a "Topicmaps"-Topic composite does not contain "Topics" contained in "Topicmap"
• checking the TopicmapViewmodel?.toJSON()-raw-data-set of a "Topicmap" does not contain a "Topic" (despite there is a "Topic Mapcontext" relation)

Issue 1: So it seems to me that just using the TopicmapService? and call "addToTopicmap(topicmapId, topicId, null); is not sufficient / leads to numerous problems. I can't find out by myself how to use it. And a quick search through numerous other plugins (source code) has not yielded any helpful code-passages using this method.

Issue 2: Existence check of "Topic" in "Topicmap". How to? Isn't it that one "Topic" can only occur once in a "Topicmap"? But maybe issue (C) is a follow-up of (A).

[Malte]

To clarify: (B) is of course thrown when I try to add a "Topic" again to a "Topicmap" the way described above.

[jri]

The problem is the null in your call. The topic needs "view properties", coordinates in particular.

addTopicToTopicmap(topicmapId, topicId, new CompositeValueModel()
    .put("dm4.topicmaps.x", x)
    .put("dm4.topicmaps.y", y)
    .put("dm4.topicmaps.visibility", true)
)

Standard view properties comprise x, y, and visibility.
(In conjunction with a Viewmodel Customizer you could add custom view properties as well.)

[jri]

Replying to Malte:

(C) I could not find a way to look for existing "Topics" in a "Topicmap" since "TopicmapService?" doesn't offer me "getTopicmapTopics()" (or something equivalent)

Yes, the public Topicmaps API is currently not sufficient.
I plan to extend it in 2 regards today:

1. A TopicmapViewmodel? gets 2 public methods:
   • getTopics() which returns an Iterable<TopicViewmodel?>
   • getAssociations() accordingly

2. The TopicmapsService? gets a new method:
   • boolean isTopicInTopicmap(topicId, topicmapId)

The latter can be emulated already by dms.getAssociation(). Tell me if you need details.

[Malte]

Ok, thanks. Now the topics are visible in my topicmap via the webclient.

But I still don't have a solution for an existence check (to avoid trying to add a Topic twice to a topicmap). The added topics don't appear (when using workaround b, checking the TopicmapViewmodel?) in the toJSON() representation, in fact the "topics:[]" list of that topicmpa remains empty. In fact it seems to remain empty when I create a simple "Note" topic in that map.

Any ideas on how I can accomplish that? Aha, OK. Don't worry, now I could also implement such existence check by myself, but yeah, the Topicmap needs this definitely. As you like, maybe you had other things on mind for today.

[jri]

Replying to Malte:

Issue 2: Existence check of "Topic" in "Topicmap". How to? Isn't it that one "Topic" can only occur once in a "Topicmap"?

For the moment you can perform a "topic in topicmap?" existence check this way:

Association assoc = dms.getAssociation("dm4.topicmaps.topic_mapcontext",
    topicmapId, topicId, "dm4.core.default", "dm4.topicmaps.topicmap_topic", false);
if (assoc != null) {
    // topic exists in topicmap
}

This works already.
Of course isTopicInTopicmap() as proposed above would be more comfortable.

And, yes, a topic can occur only once in a topicmap.

[jri]

I addressed these issues in new ticket #555

[jri]

The Topicmaps API extension is now realized (#555).