为什么在rails 2中使用link_to时在路由文件中添加连接

Question

I was trying to accomplish the following:

<%= link_to "Log out", {:controller => 'users', :action => 'logout' }, :class => 'menulink2' %>

But it didn't work, it always redirected me to a show view. I had to had the following to my routes.rb:

map.connect 'users/logout', :controller => 'users', :action => 'logout'

Why didn't rails recognize the action I was passing ('logout')?

Answer 1

That logic has to be specified somewhere. There's got to be some mapping from the hash {:controller => 'users', :action => 'logout'} to a url, and the place that's done in rails is the routes.rb file. In older versions of rails many routes.rb came with a default at the end:

map.connect ':controller(/:action/(:id(.:format)))'

Which would make it so that most any:controller, :action hash could be specified and then routed to host.url/:controller/:action .

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With the more modern versions resource-based routes are heavily favored, and controllers which don't follow rails' REST conventions (ie having only :index,:show,:create,:new,:edit,:update,:destroy methods) generally have to have their routes explicitly specified in some way.

(Either with map.resources:users, :collection => {:get =>:logout} or with map.connect( 'some_url', :controller => 'users', :action => 'logout'}) )

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I'm guessing, but the reason they did that is probably that the actions of a controller are really just its public methods.

It's frequently nice to have public methods in your controllers that aren't url-end-points for testing purposes.

For instance, you could have before_filter s as public methods that you might want to test without having to use @controller.send(:your_before_filter_method) in your test code.

So they whitelist the resource actions, and make the others unreachable by default. Let me look through the rails changelog and see if I'm right.