XOM API for Processing XML with Java

[Axel von Engel <a.vonengel AT gmail.com>]

Thanks for the quick response. I tried to keep the initial mail short, but
apparently that was too short ;)

I'll prepare a repo with an example, but it will take me a couple of days
at least. I might not be able to show the XSL Transformation error I
mentioned, though. I can't publish the involved stylesheets without
approval from the company, and that will probably take ages.

Am Sa., 4. Mai 2019 um 01:10 Uhr schrieb Elliotte Rusty Harold <
elharo AT ibiblio.org>:

> Interesting. It's hard to follow all that without an example though so
> I'm not sure whether XOM is doing something wrong or what. If you
> could bundle this into a self-contained example, or best of all, a
> unit test, I could take a look.
>
> On Fri, May 3, 2019 at 3:44 PM Axel von Engel <a.vonengel AT gmail.com>
> wrote:
> >
> > Hi everyone,
> >
> > (This got a bit long, see last paragraph for TL;DR)
> >
> > I recently started to work on migrating a DocBook toolchain to a Gradle
> > plugin, and was looking into doing all the transformations via SAX in
> Java.
> > The pre-existing toolchain at the company uses a variety of pre- and
> > post-processing XSL stylesheets, and even used different processors for
> > those.
> >
> > My first approach was the following:
> > 1. Parse the source via Xerces
> > 2. Construct a TransformerHandler backed by Saxon for each of the
> > stylesheets
> > 3. Use a FOP renderer as the final SAX ContentHandler to create PDF
> output
> >
> > This worked pretty well, until I ran into this lovely Xerces issue:
> > https://issues.apache.org/jira/browse/XERCESJ-1102
> > So basically, nested xi:include tags result in wrong xml:base attributes,
> > leading to wrong relative image paths.
> >
> > Through some searching, I found XOM, and used that on top of Xerces:
> >
> > SAXParserFactory parserFactory =
> >
> SAXParserFactory.newInstance("org.apache.xerces.jaxp.SAXParserFactoryImpl",
> > classloader);
> > // disable xInclude on the Xerces parser
> > parserFactory.setXIncludeAware(false);
> > // more config ...
> > XMLReader xmlReader = parserFactory.newSAXParser().getXMLReader();
> >
> > Builder parser = new Builder(xmlReader);
> > Document input = parser.build(rootDocbookFile);
> >
> > input = XIncluder.resolve(input, parser);
> >
> > // handler creation omitted:
> > SAXConverter saxConverter = new SAXConverter(handler);
> > saxConverter.convert(input);
> >
> > The problem with this approach: the SAXConverter does not emit xml:base
> > attributes. I later found this in the sources:
> >
> https://github.com/elharo/xom/blob/master/src/nu/xom/converters/SAXConverter.java#L98
> > Which led to my current workaround hack: Use reflection to set
> > SAXConverter.stripBaseAttributes = true
> >
> > Another approach I tried was to use XOM to do the XSL transformations
> > instead of using the SAX API. This resulted in some errors that said
> > something like "can't insert Text into Document" without any meaningful
> > hints at which XSL template might have caused it, so I didn't investigate
> > further.
> >
> > All in all, I feel this is a hack, and find it hard to believe there is
> no
> > cleaner solution. Google and Stackoverflow didn't turn up much else,
> though.
> >
> > TL;DR: My root issue is with Xerces: it can't properly resolve nested
> > xi:include tags.
> > Does someone know another solution to parse the XML, and resolve the
> > xi:include tags correctly?
> > Is there some way to debug what causes XOM to error during XSLT?
> > Or maybe there is another way to get the results from XOM to the SAX API
> > (including xml:base attributes, and without writing to disk)?
> >
> > Best regards
> > Axel von Engel
> > _______________________________________________
> > XOM-interest mailing list
> > XOM-interest AT lists.ibiblio.org
> > https://lists.ibiblio.org/mailman/listinfo/xom-interest
>
>
>
> --
> Elliotte Rusty Harold
> elharo AT ibiblio.org
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