Velocity, what's the most efficient way to check if a string is empty and not null

Question

I often have cases when a string value is absent and/or empty. Is this the best way to test this condition?

#if( $incentive.disclaimer && $!incentive         


        

Answer 1

You want Quiet Reference Notation: $!incentive.disclaimer

Bla bla $!incentive.disclaimer. 

If $incentive.disclaimer is null or "", Velocity will render:

Bla bla .

Refer to the official Guide section: https://velocity.apache.org/engine/devel/user-guide.html#quiet-reference-notation

Sometimes you do need #if

Most common case when you do want #if: your variable is just a part of a bigger piece of text and you don't want to show it if the variable is empty. Then you need this:

#if($incentive.disclaimer && !$incentive.disclaimer.empty) 
    Please read our incentive disclaimer:
    $incentive.disclaimer
#end