XSL Pattern Matching

• In the previous section we saw markup lines like: <xsl:template match="/"> and <xsl:apply-templates select="last"> These are examples of simple pattern matching. The first pattern matches the root node of the document, while the second one matches the last element (within the current element in the source tree).

• In this section we will cover some of the most useful features of XSL pattern matching. (For a more detailed description of patterns available in XSL, see the XSLT 1.0 Recommendation.

• XSL patterns use a similar syntax to file pathnames.

  /	is used to match child nodes. For example, author/last matches all last elements that are children of the author element (beneath the current element).
  Lab 4A
  Lab 4B
  //	matches descendant nodes. For example, writers//last matches any last element appearing anywhere beneath the writers element (not just immediately under it).
  |	matches several types of nodes. For example, last|first matches any last element and any first element beneath the current node.
  .	matches the current node. It is useful when used with //. For example: .//first matches any descendant element named first.
  ..	selects the parent of the current node. For example: ..//author matches all author sibling elements of the current element.
  *	can be used as a wildcard. For example: author/* matches any element that has a author parent.
  id()	matches elements with a unique ID. For example: id("0001") matches the element with unique id 0001.