topichead and metadata inheritance

[Gahr]

Hi,

I am trying to figure out how the <topichead> element works exactly in DITA. As I understand it, it is meant to create a heading and to "articificially" group up <topicref> elements together so as when the DITA map is rendered as a TOC, it creates a hierarchy and new TOC entry. Specifically, I would like to know if a <topichead> can inherit metadata from the parent root map ? And specifically an <othermeta> element declared in the root map.

My usecase is this one : I would like topics nested inside a <topichead> element to inherit from any <othermeta> element placed on the root map. Currently, I am successful in making <othermeta> cascade down to topics if the <topicref> are declared directly inside the main map or a submap. However, when nesting <topicref> inside a <topichead> (to create hierarchy for instance), this seems to prevent <othermeta> inheritance to the child topics. Neither <topichead> or the nested topics have that element when rendering with DITA OT.

I am using DITA spec 1.3 with DITA OT 2.3.3, for reference.

Thank you in advance for any help you'll be able to provide !

Best,

[Radu]

Hi,

The topichead is usually useful to create titled sections in the documentation, it resembles a topicref but without a reference to a topic.

According to the DITA 1.3 specification:
https://www.oxygenxml.com/dita/1.3/spec ... adata.html
the <othermeta> element never cascades to child topicref elements.

You are using a very old DITA OT publishing engine, released about 6 years ago and no longer maintained in any way.
Older DITA OT publishing engines (like yours) would in general cascade <othermeta> from the map to the topics, but in newer DITA OT versions (the current version is 3.7) at some point this cascading for <othermeta> was inhibited completely as this is how it was defined in the DITA 1.3 specification.

Regards,
Radu

[Gahr]

Hi Radu,

Thank you for your answer. I am aware that according to the DITA 1.3 spec <othermeta> element never cascades.

I also know the DITA OT team corrected the incorrect behavior in 3.5 (https://www.dita-ot.org/3.5/release-not ... v3.5__bugs)

The thing is, the DITA OT archive is actually the one of a customer, which relies on <othermeta> inheritance for specific usecase and needs this inheritance to happen.

So, in short, is there a way for a <topichead> element to inherit metadata (not only othermeta) ? According to this table :
https://docs.oasis-open.org/dita/dita/v ... adata.html

Some metadata are allowed to cascade down. Do the ones listed in the table as "cascade to child <topicref> elements? yes" can actually cascade into topicrefs nested into a topichead element ?

[Radu]

Hi,

The thing is, the DITA OT archive is actually the one of a customer, which relies on <othermeta> inheritance for specific usecase and needs this inheritance to happen.

I understand, it's just they need a feature which is not covered in the specification. For example if I were to try adding support for cascading othermeta from the map to the topics with DITA OT 3.7 I would probably take the DITA OT Java code which is freely available and change it to revert the changes in the issue: https://github.com/dita-ot/dita-ot/pull/3326.
I do not think this can be done in another way, the changes to inhibit othermeta propagation were done in the Java code so I suspect they cannot be inhibited by a DITA OT plugin.

Some metadata are allowed to cascade down. Do the ones listed in the table as "cascade to child <topicref> elements? yes" can actually cascade into topicrefs nested into a topichead element ?

Yes, they should, but I'm not using DITA OT 2.x. But you can test this on your side, take a DITA Map with such a structure and one or two topics, publish it to XHTML, set the "clean.temp" parameter to "no", after publishing look in the transformation temporary files folder at the content of the processed topics and see if they contain the metadata passed from the DITA Map side.

Regards,
Radu

[Gahr]

Thank you Radu, your anwser was very helpful.

I performed the test as you suggested and yes, the nested topics inherit from the metadata.

The last "pain" point is that it doesn't seem the <topichead> element can have metadata attached to it by itself, or am I incorrect ? I do not even see the topichead element inside the temporary transformation folder. The lack of metadata on the topichead element is an issue in the context of my client.

Kind regards,