Ruby-on-rails 带有可选参数的路由

Routing with an optional parameter

提问by Alessandro DS

I added in the route file:

我在路由文件中添加：

map.show_book "/show_book/:name/year/:year", :controller => "book", :action => "show_version"

I also added:

我还补充道：

map.show_book "/show_book/:name", :controller => "book", :action => "show_version"

to show the latest book without specifying the year.

显示最新的书而不指定年份。

But it doesn't work, it cannot find the route in "show_book/NAME" if I don't pass the year.

但它不起作用，如果我不通过年份，它在“show_book/NAME”中找不到路线。

Do you have some ideas why it doesn't work ?

你有什么想法为什么它不起作用？

THANKS !

谢谢 ！

PS. I know that I can use year as parameter with "?year=XXXX", but I want to use the year as a part of the URL

附注。我知道我可以使用“?year=XXXX”作为参数使用年份，但我想使用年份作为 URL 的一部分

回答by Benoit Garret

Put the optional parts between parenthesis:

将可选部分放在括号之间：

map.show_book "/show_book/:name(/year/:year)", :controller => "book", :action => "show_version"

and remove the second route.

并删除第二条路线。

Update

更新

The above answer is only for rails 3 and above. Inverting the two routes definitions fixed the problem (see Alessandro's comment below).

以上答案仅适用于 rails 3 及以上版本。反转两个路由定义解决了这个问题（见下面亚历山德罗的评论）。