Re: XLAT Question

On Apr 13, 2026, at 4:59 PM, g4-lisz@tonarchiv.ch wrote:

I read about the default / alternation syntax for string expansion, like %{%{Foo}:-bar}.

But what I needed is this: if (foo != '' ) ? '[ %{foo} ]' : 'null'.

This is for a JSON request string in a REST module configuration. The request property in question must be a JSON array ( [ .. ] ) or 'null'.

I could use Unlang IF and declare the complete JSON request in different versions depending on foo. But I would prefer to do this with expansion inside the JSON string definition, if possible.

You'll have to use 'if'. There is a mods-available/json, and you can do: %{json_encode:&foo} Except that if "foo" doesn't exist, it returns an empty json object: "{}" Alan DeKok