Fix line endings.
[sitka/doc/style.git] / style / style-pi.xml
1<?xml version="1.0" encoding="utf-8"?>\r
2<chapter xml:id="style-pi" xmlns="" version="5.0" xml:lang="EN"\r
3 xmlns:xi="" xmlns:xlink="">\r
4 <info>\r
5 <title>Processing instructions</title>\r
6 </info>\r
8 <para>Processing instructions (PIs) are written into the xml when the desired output cannot be\r
9 achieved with DocBook elements and attributes alone. PIs may also be used to force special\r
10 formatting in only part of a document. For a more technical introduction see Bob Stayton's\r
11 <link xlink:href=""\r
12 xlink:title="">DocBook\r
13 XSL: The Complete Guide</link>. There are also lists of DocBook-specific processing\r
14 instructions for <link\r
15 xlink:href=""\r
16 xlink:title=""\r
17 >html</link> and <link\r
18 xlink:href=""\r
19 xlink:title=""\r
20 >pdf</link> output.</para>\r
22 <para>PIs should be used sparingly: it is easier to maintain documents that achieve the desired\r
23 output with DocBook elements and <link\r
24 xlink:href=""\r
25 xlink:title=""\r
26 >stylesheet parameters</link>. However, there are a few cases where PIs may be\r
27 necessary:</para>\r
29 <itemizedlist>\r
30 <listitem>\r
31 <formalpara>\r
32 <title>Force line break</title>\r
33 <para>Line breaks should not be used for spacing between elements; this is much\r
34 better done with CSS and XSL. Hoever, if entering multiple lines that must be\r
35 displayed in succession but without the separation of a new paragraph, you may\r
36 use the linebreak PI. The following code</para>\r
37 </formalpara>\r
38 <programlisting>\r
39 <![CDATA[<para>First line <?linebreak?>Second line <?linebreak?>Third line</para>]]> \r
40 </programlisting>\r
41 <para>Will output</para>\r
42 <informalexample><para>First line <?linebreak?>Second line <?linebreak?>Third line</para></informalexample>\r
44 <caution><para>This only works if\r
45 custom stylesheets include the following code, described in <link\r
46 xlink:href=""\r
47 xlink:title="">Bob Stayton's\r
48 DocBook XSL</link>. Sitka's customization layer includes this template as of June\r
49 30, 2010:</para>\r
50 <para>\r
51 <![CDATA[<xsl:template match="processing-instruction('linebreak')">\r
52 <fo:block/>\r
53 </xsl:template>]]> \r
54 </para></caution>\r
55 </listitem>\r
56 \r
57 <listitem>\r
58 <formalpara><title>Include external content</title><para>To insert external content into the html output use the <emphasis>dbhtml-include</emphasis> processing instruction as described in <link xlink:href="" xlink:title="">DocBook XSL</link>.\r
59 This could be used to add a custom search box to the title page, an animated tutorial in the relevant section, or any other content in valid xhtml.</para></formalpara>\r
60 </listitem>\r
61 \r
62 </itemizedlist>\r