Am 21.08.2014 um 19:59 schrieb Michael Kay:

> If the parent has a content model A, B, C, D, and any of the four might be
absent, then you could try doing
>
> <xsl:apply-templates select="optional(A, $A), optional(B, $B), optional(C,
$C), optional(D, $D)"/>
>
> where optional(X, Y) is a function that selects X if present or Y otherwise,
and $A, $B etc are global variables containing default elements of each type
(or some other marker to indicate that the element is absent).

Can the function be avoided by writing

<xsl:apply-templates select="(A, $A)[1], (B, $B)[1], (C, $C)[1], (D,
$D)[1]"/>

This method was mentioned earlier in this list and I used it since several
times as a method to handle default values.

- Michael