String Concatenation in EL

Question

I would like to concatenate a string within a ternary operator in EL(Expression Language).

Suppose there is a variable named value. If it's empty, I want to use some default text. Otherwise, I need to append it with some static text.

${(empty value)? "none" : value + " enabled"}

This will not compile however. What would be a correct way to write this? Or is this even possible?

user_1031945 · Answer

Since Expression Language 3.0, it is valid to use += operator for string concatenation.

${(empty value)? "none" : value += " enabled"}  // valid as of EL 3.0

String Concatenation Operator

To evaluate
A += B 
Coerce A and B to String.

Return the concatenated string of A and B.