Routing in Symfony2: optional parameter en four urls for one route

问题

In my Symfony2 application I would like to make four urls possible with one route:

1. a-lot-of-other-stuff/report/-20 (negative number)
2. a-lot-of-other-stuff/report/40 (positive number)
3. a-lot-of-other-stuff/report/ (no number)
4. a-lot-of-other-stuff/report (no number and no / )

My route currently looks like this:

report:
    pattern:  /report/{days}
    defaults: { _controller: "AppReportBundle:Report:dayReport", days = null }

The action is defined as:

public function dayReportAction($days = null)
{
    // my code here
}

This currently makes url 1 and 2 working but in the case of url 3 and 4, I get an error

Route not found

How can I make the parameter "days" optional?
And if the parameter is not provided, how can I allow the / to be omitted as well?

回答1:

Here's a way to do this

routing.yml

report:
    pattern: /report/{days}
    defaults: { _controller: "AppReportBundle:Report:dayReport", days: null }
    requirements:
        days: -?\d+

report_reroute:
    pattern: /report/
    defaults:
        _controller: FrameworkBundle:Redirect:redirect
        route: report
        permanent: true

Since requirements is a regexp pattern it lets you have a negative number.

The reroute section forces the route /report/ to redirect on /report
You can read about this on: Cookbok Entry - Elnur's Answer

With such behaviour, you would have:

Route       | Action                 | Parameters
------------|------------------------|-------------
/report     | dayReportAction        | $days = null
/report/    | 301 to /report         |
/report/60  | dayReportAction        | $days = 60
/report/-4  | dayReportAction        | $days = -4
/report/foo | 404                    |

来源：https://stackoverflow.com/questions/17059843/routing-in-symfony2-optional-parameter-en-four-urls-for-one-route