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It might not sound like it, but a redirection is a response. Redirects don t really happen on the server side. Instead, a response is sent to your browser that tells it to perform a redirection to another URL. The specifics of issuing a redirect aren t something you need to worry about, though, since Rails provides a specialized method to take care of the internals. That method is called redirect_to, and it s one you ll find yourself using a lot, so it s a good idea to get familiar with it. As you can see from the example in the create action, redirect_to takes a hash of options. Most of the time, you ll specify the name of a controller, action, or both. The current controller is presumed unless a controller value is given, so in our case, Rails will redirect to the index action in the users controller. You can also pass around parameters when redirecting; any key/value pairs you append to the redirect will be parameterized and become part of the params hash.

Let s try submitting the form again. Make sure you leave the form empty so you can see whether the validations are working as expected. Sure enough, the form doesn t save. In fact, you ll notice that you re still on the same screen and that the form elements are highlighted in red, as shown in Figure 6-2.

If you look at the HTML source, you ll see that the input tags are surrounded by div elements with the class name fieldWithErrors:

<div class="fieldWithErrors"> <input class="large" id="user_login" name="user[login]" size="30" type="text" value="" /> </div>

Rails does this automatically for any fields that failed validation, and you can use these classes to style invalid elements.

Note The style rules that turn the invalid fields red are generated by the scaffold generator and are in

public/stylesheets/scaffold.css. All static files, such as stylesheets and images, are located in the public directory.

But wait a minute. Where is the formatted list of errors that we got with our invalid events Well, the scaffold generator added the helper that displays these, but if we want them to show up here, we ll have to do it ourselves. We ll use the error_messages_for helper and tell it the name of the model whose errors we want to see in this case, User. Add the following to the top of the new template in app/views/users/new.rhtml:

Now submit the form one more time, again with empty fields. You should see the error messages, as shown in Figure 6-3.

With all the plumbing in place, let s submit the form with valid data. If all goes according to plan, the new user should be created, and you ll be redirected to the events controller, where you ll see the friendly flash message we set. Notice that if you refresh the page using your browser s refresh button, the flash message will disappear.

The next step is to add the edit and update actions to the controller. We ll also need an edit template. Create a new action called edit, as shown in Listing 6-6 (it looks a lot like the new action).

Next, create the edit template in app/views/users/edit.rhtml as shown in Listing 6-7.

<h2>Edit User</h2> <% form_tag :action => 'update' do %> <p><label>Login:<br /> <%= text_field :user, :login %></label></p> <p><label>Email:<br /> <%= text_field :user, :email %></label></p> <p><label>Password:<br /> <%= password_field :user, :password %></label></p> <p><label>Password confirmation:<br /> <%= password_field :user, :password_confirmation %></label></p> <p><%= submit_tag 'Save Changes' %></p> <% end %>

As you can see from the form_tag method, this form will submit to the update action on the events controller. We need to add the update method to our controller, so let s do that now, as shown in Listing 6-8.