I failed to generate the "single HTML file".
The default Makefile task, which creates multiple HTML files, works properly, because it confines itself to create links to SVG files. The SVG structure keeps hidden to the Docbook validation and processing - Docbook recognises only some additional links. What I have tried to generate a single HTML file is the use of xi:XInclude before validating and further processing. In this case the SVG structure is visible to Docbook.
In general it is possible to use SVG within Docbook 4.x, if you switch the doctype to
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook SVG Module V1.1CR1//EN" "http://www.oasis-open.org/docbook/xml/svg/1.1CR1/dbsvg.dtd"
This is an Docbook 4.x extension (https://docbook.org/specs/wd-docbook-svg-1.1cr1) for SVG-integration. But it's only a working draft from 2004, it never reached the status of an official OASIS standard. As far as I have seen, it works (with some limitations), if the SVG data is an integral part of the xml/sgml source file. I failed to combine it with xi:XInclude. In opposite to this the combination of xi:XInclude, SVG, and Docbook 5.1 works well. In my opinion this results from the fact, that the structure of Docbook 4.x is based on a DTD, whereas Docbook 5.x uses Relax-NG (and generates xsd files out of rng). DTDs natively are not namespace-aware, you must do some trickery to handle namespaces. Docbook 5.x is not only namespace aware, it natively includes definitions for SVG and other important standards like MathML.
My questions to the community are:
- Does anyone has an idea how to generate single HTML file in the actual situation?
- Shall we delay the SVG integration until we have switched to Docbook 5.x? This task is a great step, but it must be done in any case, because Docbook 4.x is outdated since many years. Btw: Because of other problems (https://github.com/docbook/docbook/issues/74) it is likely that we cannot use 5.1 but have to wait for the upcoming release 5.2.
Kind regards
Jürgen Purtz