How to check if a variable exists in a FreeMarker template?
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        Published on 2008-11-20T20:21:42Z
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            2010/03/18
            8:01 UTC
        
        
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Hi,
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.
Cheers, Don
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