Inasmuch as the Print and Page Layout Community Group at the W3C is looking at how to get feedback from the XSL formatter and I’ve also been reading about how Saxon-CE handles user input, I’m now wondering whether the same sort of pattern could be adapted to handling feedback from the XSL formatter. Saxon-CE does it through template rules that match the element that receives the event and are in a mode that reflects the type of event, and similarly an XSL formatter could trigger on exceptional events such as overflow occurring or even on mundane events such as completion of a page sequence, and the templates in the corresponding modes could match on either FOs in the FO tree or areas in the area tree. Continue reading
xsl:attribute-set is most often thought of for adding constant sets of XSL-FO properties, it’s easy to forget that, as it says in the XSLT 2.0 spec:
Evaluating the same attribute set more than once can produce different results, because although an attribute set does not have parameters, it may contain expressions or instructions whose value depends on the evaluation context. Continue reading
Inasmuch as a Windows partition that wouldn’t boot frustrated and inconvenienced me for nearly a week, and the solution, when I found it, took only a couple of minutes, I’m writing it up here.
The symptom when trying to boot into Windows was a black-and-white screen of death containing:
File: \Boot\BCD Status: 0xc0000034 Info: The Windows Boot Configuration Data file is missing required information
The official Microsoft advice at http://support.microsoft.com/kb/927391/en-us didn’t help. What did work was the second option, “Manually Repairing the Windows Bootloader”, from http://neosmart.net/wiki/display/EBCD/Recovering+the+Windows+Bootloader+from+the+DVD:
attrib -h -s C:\boot\BCD del C:\boot\BCD bootrec.exe /rebuildbcd
Happily, I didn’t need to do the third, “Nuclear Holocaust” option from that page.
One, in the XSLT and XQuery track, is an update of the Developing and Testing in XSLT talk, again alongside Jeni Tennison, that got us such a good review last year:
Unit tests, profiling, debugging and, increasingly, test-driven development are part of the bread and butter of working with other programming languages but are not always so with XSLT or XQuery. In test-driven development, which is a fundamental part of agile approaches to software development, the developers write tests that describe the desired behaviour of their application, then write code that meets the tests. This style of development keeps code focused, avoids breaking existing code and facilitates refactoring.
In this session, Jeni Tennison and Tony Graham will describe both the state of the art in testing and debugging XSLT and XQuery and how test-driven development applies to XSLT and XQuery development. In particular, they will focus on the use of the XSpec testing framework.
The other, in the Publishing track, is XML and Publishing Workflows:
Some formats are better or worse than others for capturing and/or representing the information for publishing purposes. Can you create and manage life-cycle workflows which rationalise or regularise mixes of formats using XSLT and other XML toolsets? Should XML be the beginning of your publishing workflow, the hub format in the middle, the result, or all three? How can XSLT and related tools be used to cover up the deficiencies or excesses of the source XML? What are the arguments for moving authors towards submitting in XML (or not)? For moving editors?
Incorporating both live examples and war stories, Tony Graham will lead an examination of XML in publishing workflows, the advantages and disadvantages of using XML at each stage, and some of the tools and techniques available to you.
XML Summer School 2012 is on September 16–21 2012 at St Edmund Hall, Oxford University.
Inasmuch as I was in primary school in Australia when I first read it as a dead-tree book, it’s something of a turn for the books as well as a turn of the books that I’ve just finished reading Robbery Under Arms by Rolf Boldrewood as an EPUB while living and working in Ireland and, now, England. I think at the time I would have found the medium even more unlikely than the geography, but as the ready availability of EPUB readers has given new life and new audiences to many out-of-copyright books, when I was first stocking up on EPUBs I specifically looked for the EPUB of Robbery Under Arms since I was unlikely to find it the dead-tree version in either an Irish library or an Irish bookstore.
“My name is Dick Marston” as the opening words of Robbery Under Arms may not have the recognition nor the ring of “Call me Ishmael” (though for a great young-adult read, Don’t Call Me Ishmael), but it is one of the great Australian novels. If you want to read the EPUB, a search for ‘”Robbery Under Arms” EPUB’ will turn up several sources.
Inasmuch as I’d been threatening since the XML Summer School last year to do it, I’ve made a custom Ant task for running XML Calabash, currently only in my fork at firstname.lastname@example.org:MenteaXML/xmlcalabash1.git.
You can use this task to process:
- A single input file to produce a single output file
- A set of input files, processed one at a time, to produce a set of output files
- Multiple input files as the input to one XProc input port processed to produce a single output file
- Any of the above with additional input ports to each of which are applied one or more input files whose file names may be either fixed or mapped from the name(s) of the current main input file(s)
- Any of the above with additional output ports whose file names may be either fixed or mapped from the name(s) of the current main input file(s)
- Any of the above with Ant defaulting to not running the pipeline when the outputs are already up-to-date compared to the inputs and the pipeline
You can also specify options and parameters to be used by the pipeline. Continue reading
Inasmuch as it’s useful, when editing an Ant build file, to have a list of the targets in the file and the ability to jump to any of them, my Ant mode at email@example.com:tkg/ant-mode.git currently only does two things: make a “Ant” menu that lists all the targets and associates a RELAX NG compact syntax schema with build files. Continue reading
use-when is one of the standard attributes in XSLT 2.0 (and later) rather than being on a particular XSLT element, it seldom gets much of a mention; e.g., currently only 568 mentions on the XSL-List according to MarkMail (and some of those are false positives).
xsl:use-when on non-XSLT elements) is for “conditional element inclusion” and is very useful for excluding elements that either aren’t currently useful or that will cause errors if acted upon. The
use-when in the example below causes the
xsl:value-of to be used only when
saxon:line-number() is available, thereby avoiding the
Saxon extension functions are not available under Saxon-HE message from more recent versions of Saxon HE where
saxon:line-number() is no longer available but
producing a useful result on older Saxon HE versions where the function
<!-- Leftover intermediate elements. --> <xsl:template match="t:*"> <xsl:if test="$debug"> <xsl:message> <xsl:value-of select="t:node-basename(.)" /> <xsl:value-of use-when="function-available('saxon:line-number')" select="concat(':', saxon:line-number())" xmlns:saxon="http://saxon.sf.net/" /> <xsl:text> :: </xsl:text> <xsl:copy-of select="." /> </xsl:message> </xsl:if> <xsl:apply-templates /> </xsl:template>
use-when expression is evaluated very early in the processing of the stylesheet, and you can’t use variable references in the expression. So don’t be tempted to try:
<xsl:message use-when="$debug"> ... </xsl:message>
Inasmuch as I’d wanted for a long time to have an excuse to write an Emacs mode that uses a Semantic Wisent parser, I recently started writing a new mode for RELAX NG compact syntax files. The mode-in-progress is available on GitHub at https://github.com/tkg/nrnc.git, and here’s my thoughts so far on using Wisent: Continue reading
Inasmuch as, back in January, I was teaching another XML course, I reviewed the basis for draconian error handling in XML in light of the sea change in recent years towards HTML5-style completely-defined error recovery.
At the time of the draconian error handling decision, I was on the larger “W3C SGML Working Group” mailing list that provided input, clamour, and distraction to the core “W3C SGML Editorial Review Board” that did the work and made the decisions on the road to XML. I followed the discussions on the mailing list at the time (as much as humanly possible), and the message about this that stuck in my mind is the “ERB votes on error handling” message from Tim Bray on behalf of the ERB, particularly this section:
2. We have a strong political reality to deal with here in that for the first time, the big browser manufacturers have noticed XML and have together made a strong request: that error-handling be completely deterministic, and that browsers not compete on the basis of excellence in handling mangled documents. It was observed that if they wanted to do this, they could just do it; but then pointed out that this is exactly why standards exist – to codify the desired practices shared between competitors. In any case, if we want XML to succeed on the Web, it will be difficult to throw the first serious request from M & N back in their face.