Processing part of a document

Processing part of a document
	Chapter 6. HTML output options

You may want to generate output for only part of large DocBook document. For example, you might need just one book from a set document, one chapter from a book document, or one refentry page from a reference document. When you are developing a back-of-book index, it helps to periodically generate only the index output so you can check it. The DocBook XSL stylesheets have a parameter that lets you output part of a document.

There are two conditions to use this feature:

The content you want to output is contained in a single element. You can't use this feature to output an arbitrary selection of elements.
The selected element must have an id attribute on it.

If these two conditions are met, then generating output for one element is easy. You process the document as you normally would, but you set the stylesheet parameter rootid to the id attribute value of the element you want to process. For example, if you have a book with three chapters:

<book>
<chapter id="intro">
  ...
</chapter>
<chapter id="using">
  ..
</chapter>
<chapter id="administering">
  ...
</chapter>
</book>

You can generate an HTML file for the second chapter with a command like this:

xsltproc  \
    --stringparam  rootid  "using"  \
    --output  chap2.html  \
    html/docbook.xsl  myfile.xml

The chap2.html output file will contain just the second chapter. Note these features:

The entire document is still parsed, so there won't be signficant savings of processing time.
The content is still processed within the context of the entire document, so it will still be labeled "Chapter 2".
Any cross references to other chapters will be properly formed, but the links won't actually go anywhere because the targets are not included in the output.


Chapter 6. HTML output options		Chunking into multiple HTML files