notnull Function

Takes one argument

This function returns:

0– null argument

1– non-null argument

Example 1

The value of the following expression is 1 if the firstname has been set or 0 (zero) if firstname is null.

<notnull>
   <ref>firstname</ref>
</notnull>

Example 2

The value of the following expression is 0 because the value is null.

<notnull><null/></notnull>