Rails%203%20In%20Action

18 CHAPTER 1 Ruby on Rails, the framework
In the beginning...
In really early versions of Rails, you had to generate links like this:
link_to "Back", { :controller => "purchases",
:action => "show",
:id => @purchase.id }
This hash was then interpreted and matched to a route, like /purchases/1. You can
still use it today in Rails 3 if you wish, but it’s not best practice. The hash can be
shortened:
link_to "Back", "/purchases/#{@purchase.id}"
These days, the following is best:
link_to "Back", @purchase
By using the routing helpers introduced in Rails 2 and still available in Rails 3.1, you
can have much shorter link_to calls in your application, increasing the readability
of the code throughout.
Let’s try filling in this form now, for example, by changing the cost from 100 to 10 and
clicking Update Purchase. You now see the show page but with a different message,
shown in figure 1.9.
Clicking Update Purchase brought you back to the show page. How did that happen?
Click the back button on your browser and view the source of this page, specifically
the form tag and the tags directly underneath, shown in the following listing.
Listing 1.14 The HTML source of app/views/purchases/edit.html.erb
form action="/purchases/
2" class="edit_purchase" id="edit_purchase_2" method="post"
div style="margin:0;padding:0;display:inline"
input name="_method" type="hidden" value="put" /
/div
...
This form’s action points at /purchases/2, which is the route to the show action in
PurchasesController. You should also note two other things. The method attribute of
this form is a post, but there’s also the input tag underneath.
The input tag passes through the _method parameter with the value set to "put".
Rails catches this parameter and turns the request from a POST into a PUT. This is the
Figure 1.9 Viewing an updated purchase