How to check if a variable exists in a FreeMarker template?

Question

I have a Freemarker template which contains a bunch of placeholders for which values are supplied when the template is processed. I want to conditionally include part of the template if the userName variable is supplied, something like:

[#if_exists userName]

  Hi ${userName}, How are you?

[/#if_exists]

However, the FreeMarker manual seems to indicate that if_exists is deprecated, but I can't find another way to achieve this. Of course, I could simple providing an additional boolean variable isUserName and use that like this:

[#if isUserName]

  Hi ${userName}, How are you?

[/#if]

But if there's a way of checking whether userName exists then I can avoid adding this extra variable.

Answer 1

This one seems to be a better fit:

<#if userName?has_content>

... do something

</#if>

http://freemarker.sourceforge.net/docs/ref_builtins_expert.html