Common Template Reference

Norman Walsh

$Id: common.xsl,v 1.39 2003/12/06 00:07:51 bobstayton Exp $


This is technical reference documentation for the DocBook XSL Stylesheets; it documents (some of) the parameters, templates, and other elements of the stylesheets.

This is not intended to be user documentation. It is provided for developers writing customization layers for the stylesheets, and for anyone who's interested in how it works.

Although I am trying to be thorough, this documentation is known to be incomplete. Don't forget to read the source, too :-)

is.component - Tests if a given node is a component-level element
is.section - Tests if a given node is a section-level element
section.level - Returns the hierarchical level of a section.
qanda.section.level - Returns the hierarchical level of a QandASet.
select.mediaobject - Selects and processes an appropriate media object from a list
select.mediaobject.index - Selects the position of the appropriate media object from a list
is.acceptable.mediaobject - Returns '1' if the specified media object is recognized.
check.id.unique - Warn users about references to non-unique IDs
check.idref.targets - Warn users about incorrectly typed references
copyright.years - Print a set of years with collapsed ranges
find.path.params - Search in a table for the "best" match for the node

is.component — Tests if a given node is a component-level element

<xsl:template name="is.component">
<xsl:param name="node" select="."/>
  ...
</xsl:template>

This template returns '1' if the specified node is a component (Chapter, Appendix, etc.), and '0' otherwise.

Parameters
node

The node which is to be tested.

Returns

This template returns '1' if the specified node is a component (Chapter, Appendix, etc.), and '0' otherwise.


is.section — Tests if a given node is a section-level element

<xsl:template name="is.section">
<xsl:param name="node" select="."/>
  ...
</xsl:template>

This template returns '1' if the specified node is a section (Section, Sect1, Sect2, etc.), and '0' otherwise.

Parameters
node

The node which is to be tested.

Returns

This template returns '1' if the specified node is a section (Section, Sect1, Sect2, etc.), and '0' otherwise.


section.level — Returns the hierarchical level of a section.

<xsl:template name="section.level">
<xsl:param name="node" select="."/>
  ...
</xsl:template>

This template calculates the hierarchical level of a section. The element sect1 is at level 1, sect2 is at level 2, etc.

Recursive sections are calculated down to the fifth level.

Parameters
node

The section node for which the level should be calculated. Defaults to the context node.

Returns

The section level, 1, 2, etc.


qanda.section.level — Returns the hierarchical level of a QandASet.

<xsl:template name="qanda.section.level"/>

This template calculates the hierarchical level of a QandASet.

Returns

The level, 1, 2, etc.


select.mediaobject — Selects and processes an appropriate media object from a list

<xsl:template name="select.mediaobject">
<xsl:param name="olist" select="imageobject|imageobjectco                      |videoobject|audioobject|textobject"/>
  ...
</xsl:template>

This template takes a list of media objects (usually the children of a mediaobject or inlinemediaobject) and processes the "right" object.

This template relies on a template named "select.mediaobject.index" to determine which object in the list is appropriate.

If no acceptable object is located, nothing happens.

Parameters
olist

The node list of potential objects to examine.

Returns

Calls <xsl:apply-templates> on the selected object.


select.mediaobject.index — Selects the position of the appropriate media object from a list

<xsl:template name="select.mediaobject.index">
<xsl:param name="olist" select="imageobject|imageobjectco                      |videoobject|audioobject|textobject"/>
<xsl:param name="count">1</xsl:param>
  ...
</xsl:template>

This template takes a list of media objects (usually the children of a mediaobject or inlinemediaobject) and determines the "right" object. It returns the position of that object to be used by the calling template.

If the parameter use.role.for.mediaobject is nonzero, then it first checks for an object with a role attribute of the appropriate value. It takes the first of those. Otherwise, it takes the first acceptable object through a recursive pass through the list.

This template relies on a template named "is.acceptable.mediaobject" to determine if a given object is an acceptable graphic. The semantics of media objects is that the first acceptable graphic should be used.

If no acceptable object is located, no index is returned.

Parameters
olist

The node list of potential objects to examine.

count

The position in the list currently being considered by the recursive process.

Returns

Returns the position in the original list of the selected object.


is.acceptable.mediaobject — Returns '1' if the specified media object is recognized.

<xsl:template name="is.acceptable.mediaobject">
<xsl:param name="object"/>
  ...
</xsl:template>

This template examines a media object and returns '1' if the object is recognized as a graphic.

Parameters
object

The media object to consider.

Returns

0 or 1


check.id.unique — Warn users about references to non-unique IDs

<xsl:template name="check.id.unique">
<xsl:param name="linkend"/>
  ...
</xsl:template>

If passed an ID in linkend, check.id.unique prints a warning message to the user if either the ID does not exist or the ID is not unique.


check.idref.targets — Warn users about incorrectly typed references

<xsl:template name="check.idref.targets">
<xsl:param name="linkend"/>
<xsl:param name="element-list"/>
  ...
</xsl:template>

If passed an ID in linkend, check.idref.targets makes sure that the element pointed to by the link is one of the elements listed in element-list and warns the user otherwise.


copyright.years — Print a set of years with collapsed ranges

<xsl:template name="copyright.years">
<xsl:param name="years"/>
<xsl:param name="print.ranges" select="1"/>
<xsl:param name="single.year.ranges" select="0"/>
<xsl:param name="firstyear" select="0"/>
<xsl:param name="nextyear" select="0"/>
  ...
</xsl:template>

This template prints a list of year elements with consecutive years printed as a range. In other words:

<year>1992</year>
<year>1993</year>
<year>1994</year>

is printed 1992-1994, whereas:

<year>1992</year>
<year>1994</year>

is printed 1992, 1994.

This template assumes that all the year elements contain only decimal year numbers, that the elements are sorted in increasing numerical order, that there are no duplicates, and that all the years are expressed in full century+year (1999 not 99) notation.

Parameters
years

The initial set of year elements.

print.ranges

If non-zero, multi-year ranges are collapsed. If zero, all years are printed discretely.

single.year.ranges

If non-zero, two consecutive years will be printed as a range, otherwise, they will be printed discretely. In other words, a single year range is 1991-1992 but discretely it's 1991, 1992.

Returns

This template returns the formatted list of years.


find.path.params — Search in a table for the "best" match for the node

<xsl:template name="find.path.params">
<xsl:param name="node" select="."/>
<xsl:param name="table" select="''"/>
<xsl:param name="location">
    <xsl:call-template name="xpath.location">
      <xsl:with-param name="node" select="$node"/>
    </xsl:call-template>
  </xsl:param>
  ...
</xsl:template>

This template searches in a table for the value that most-closely (in the typical best-match sense of XSLT) matches the current (element) node location.