Allows to execute a part of the publisher request only if a certain test is satisfied.
Syntax:
<p:if test="..."> [... child instructions ...] </p:if>
The test attribute specifies a conditional expression (an expression evaluating to true or false) in the same format as used in the Daisy query language.
For example:
<p:if test="$MyField > 20"> ... </p:if>
If the test evaluated to true, the output of the child instructions, otherwise nothing.