default route in rails

Question

I had a doubt when i was writing rails code. In my link_to i used my route order to show my order. So:

<% @orders.each do |order| %>
    <tr>
      <th><%= order.name %></th>
      <th><%= link_to 'Mostra', order %></th>
    </tr>
<% end %>

I saw my rake routes and there was a :

order GET /orders/:id(.:format) orders#show

If i remember right i generated Order resource with scaffolding. However , when i created by hand new resources (not using scaffolding) i had a different route for my resource. For example , i have something like name_resource_show(:id) for the show. This kind of style is good cause i understand that i have to pass the id , if i want to see a specific resource. But in the case before , the case of order , i really don't know how rails is able to understand to use the id of the object order. And also: why i have different routes name? why i have sometimes _path and sometimes (maybe when i generate resource with scaffolding) other things? i would expect something like order_show(:id) and not simply order. how it works?

score 3 · Accepted Answer · answered Jun 22 '15 at 16:21

Rails helpers are smart enough to use model object to form url.

<%= link_to 'Mostra', order %> equivalent to <%= link_to 'Mostra', order_path(order) %> and both points to order show page.

This will generate 7 routes for your controller orders.

resources :orders

order GET /orders/:id orders#show

Here order is the helper method it provides to call routes instead of using /orders/:id.

Simply you can use order_path(order) to get route /orders/:id

Similary we get helper for all 7 routes. You can also override the helpers.

Go to below link for more information.

Reference: http://guides.rubyonrails.org/routing.html

score 1 · Answer 2 · edited May 23 '17 at 12:06

First, I recommend following the Rails conventions on routes (see the main reference article here).

Here are answers to your questions in order.

The route you got from rake routes makes sense in the following way. Look at the URL (orders/:id). Within all of your orders, the :id passed specifies which one to look at. The GET nature of the request indicates you are getting the data on that record, i.e. that it is a SHOW action.
Rails understands where the ID is because of how the routes are structured. If you had order GET /orders/:year/:id in routes, then Rails will know to look for the third parameter for the ID it needs.
The two for accessing routes options are _path and _url (see here for details), but there are some alternatives explained in the main reference article I linked at top.
You can still use the explicit route, but the order option is simply a bit of sugar Rails offers to make things easier to read.

default route in rails

2 Answers2