How to have multiple condition in an th:if tag using thymeleaf

Question

I have a text to render in three different possible colors using thymeleaf.

So the code I've made so far to test the value is:

th:if="${evaluation} > 50"
th:if="${evaluation} < 30"

And that works well.

But the third test is for values between those two. So I tried:

th:if="(${evaluation} < 49) ∧ (${evaluation} > 29)"

but it's not working, I've got this error while parsing:

org.thymeleaf.exceptions.TemplateProcessingException: Could not parse as expression: "(${evaluation} < 49) &and; (${evaluation} > 29)" (/property.html:41)

Of course, these lines are between tags since the first two are working properly.

Maybe the and operand is not correct, but the documentation of thymeleaf is not really explicit on those operands.

All ideas are welcome!

Update: I got the answer from the thymeleaf forum. The way to do it is:

th:if="${evaluation < 49 and evaluation > 29}"

Problem solved!

Answer 1

I got the answer from the thymeleaf forum. The way to do it is :

th:if="${evaluation < 49 and evaluation > 29}"

Problem solved !

Answer 2

This is what worked for me:

th:if="${evaluation lt 49 and evaluation gt 29}"

Answer 3

In my opinion, a better and more maintainable solution could be to write the evaluation code in a proper class.

class Evaluator{

private int value;
....

public boolean isBounded() {
    return value < 49 && value > 29;
}

then in thymeleaf, call the function:

<p th:if="${evaluator.isBounded()} ...

Some benefits:

1. Cleaner template.
2. Control in java code.
3. Isolation. More complex evaluations could be written without changing the template.

I hope this helps.