The Refactoring section of the Editing XSLT/XPath part of this guide describes XSLT refactoring in general. This section provides additional detail on the 'extract to xsl:function refactor..

Introduction

There are two available modes for extracting selected code to an xsl:function: full and partial. In this refactor, required context properties must be passed as parameters when the new xsl:function is invoked, this is because context properties are cleared inside an xsl:function.

Partial Mode

In the partial mode, required parameters are passed to the new function, but code in not refactored to reference the new parameters. Instead, the 'missing-context' properties are highlighted as problems.

Full Mode

The full refactor fixes 'missing-context' properties by refactoring the code to reference the relevant parameters.

A Sample Refactor

The screenshots below show sample code refactored to extract to an xsl:function.

1. The original code selected for refactoring

2. After a partial refactor: 'missing-context' problems are highlighted

2. After a full refactor: there are no 'missing-context' problems as code is updated in the refactor to let parameters provide the context

Known Restrictions

The code selected for a refactor is important. For example, in many cases it may be more effective to extract an entire xsl:merge instruction instead of a set of instructions within the child xsl:merge-action instruction.

There are known limitations in what can be achieved when passing context to an xsl:function, these are outlined below. Please note also that in general there will be cases where, because of context, it would be advisable to extract to xsl:template instead of xsl:function.

• Potential ‘missing context’ problems for the xsl:call-template instruction are highlighted but not fixed. In such cases, it’s advisable to undo the refactor and use the extract to xsl:template refactoring instead.
• The regex-group($n) expression (where $n is not a literal integer) with ‘missing context’ is a special refactoring case. It is resolved to $r.group($n) where $r.group references a context xsl:param of type map(xs:integer, xs:string), The number of items in the generated code for $r.group is set to 99 this number should be corrected manually to the expected number of regex groups given the regex used.

Context Properties

The table below lists the context properties, along with the corresponding xsl:function parameter names that will, if required, be created for an xsl:function refactor.

Context property	Parameter
current() or '.'	c.x
position()	c.p
last()	c.l
current-group()	g.current
current-grouping-key()	g.key
regex-group($n)	r.group($n)
current-merge-group()	m.current
current-merge-key()	m.key
current-merge-group()	g.current
current-merge-group($name)	g.groups($name)