variable:IsDefined

Evaluates whether a variable by some name has been initialised or not.

Returns a boolean.

variable:IsDefined( xpath >> string )

The return value is true if a variable by the name of string has been initialised, and otherwise false.

Note

A variable may be initialised and have the empty string ( '' ) as a value. The result of the following is true:

<pc:assign-default rdbms="" />
<pc:assign-var isdefined="{variable:IsDefined('rdbms')}"/>
<pc:value-of select="$isdefined"/>