Optional first parameter in routing?

Question

symfony

How to get rid of the first parameter if necessary? For example, there is a routing

index:
    path:     /{category}/{item}
    defaults: { _controller: AppTestBundle:Test:index, category = mainCategory }

If you do not pass the category, then this route does not work, you have to pervert, something like

index:
    path:     /{item}
    defaults: { _controller: AppTestBundle:Test:index }

indexWithCat:
    path:     /{category}/{item}
    defaults: { _controller: AppTestBundle:Test:index, category = mainCategory }

How to do it right?

Answer 1

Why don't you read the documentation ?