Dynamic boolean expression - ExpressionEvaluator ?

Addendum.

I got a heureka moment, when I found the trinary “?:” operator.
I.e. conditionValue ? trueValue : falseValue

But alas, it didn’t make a difference :-(

ExpressionEvaluator just returns either the expression un-evaluated, or return a missing value.

I’ve tried to encapsulate the whole expression in @Value() and @Evaluate(), but neither works.

Here’s a sample value of the expression:

How to I force FME to evaluate my expression ?

I don’t think you can use the ExpressionEvaluator to compare strings which is where the issue is.

It works if you supply an expression in an attribute that is doing a numeric test

Is there a particular reason to use the ExpressionEvaluator?

Could you build an expression like this instead?

I’m not sure what exactly you’re looking to achieve but there are probably better ways

Thanks ​@ebygomm 

I’ve never used ExpressionEvaluator before, just expressions in AttributeManager. But I really thought this transformer would be more versatile than it apparently is, judging just from its name.

No, I don’t need to use this transformer, I’m searching for a general way to evaluate dynamic expressions, as I have a multitude of different expressions which can be quite complex.

I’m now instead looking into the Python eval(), and it looks very promising.

However, I still would’ve liked a native FME solution to this problem.