How to define default date values in Symfony2 routes?

Question

If I want to create a route, where the year, month and date are variables, how can I define that if these variables are empty, the current date shall be taken?

E.g.

Answer 1

You can set $year = null, $month = null, $day = null in controller.

or maybe in route:

year:  null,
month: null,
day:   null,

Then in controller you should get last posts if variables = null, or posts by date.