What is wrong in this Scaffolding like way?

Hey guys, i generally haven't used scaffolds, though i've been messing with Rails for quite some time. I would most of the times do things manually.

Now, i'm trying to create a restful like form implementation. I have a form_for like :

<% form_for @alliance, :url => create_alliance_path do |f| %>

   <% if @alliance.errors.any? %>  
   <div id="errorExplanation">  
     <h2><%= pluralize(@alliance.errors.count, "error") %> prohibited this user from being saved:</h2>  
     <ul>  
     <% @alliance.errors.full_messages.each do |msg| %>  
       <li><%= msg %></li>  
     <% end %>  
     </ul>  
   </div>  
   <% end %> 

    <%= f.label :name %>
    <%= f.text_field :name %><br>

    <%= f.label :description %>
    <%= f.text_area :description %><br>

    <%= f.label "Image URL" %>
    <%= f.text_field :image_url %><br>

    <%= f.submit "#{t 'alliance.create_button' }" %>

<% end %>

The routes are :

  scope :path => '/alliances', :controller => :alliances do
    get 'show/(:id)' => :show, :as => 'alliance'
    get 'new' => :new, :as => 'new_alliance'
    post 'create' => :create, :as => 'create_alliance'
  end  

Now, this form is generated by the new action :

def new
    @alliance = Alliance.new
end

And the submission is like :

def create
    @alliance = Alliance.new(params[:alliance])

    if @alliance.save
        flash[:error] = I18n.translate 'e开发者_开发百科rror.alliance_created'
        redirect_to alliance_path and return
    else
        redirect_to new_alliance_path and return
    end
end 

Now, if there is an error, i do not get it back when redirecting to new_alliance_path. At first sight, this seems normal, as new recreates the @alliance instance variable. However, in some scaffolding code, it seems like it's done in a similar manner.

Can you see what i'm doing incorrectly ?

Your create action should look more like this:

def create
    @alliance = Alliance.new(params[:alliance])

    if @alliance.save
        flash[:error] = I18n.translate 'error.alliance_created'
        redirect_to alliance_path
    else
        render :action => :new
    end
end

When calling redirect you start the complete request life-cycle again. Instead you just want to re-render the new view with the current @alliance object.

I also noticed you are using 4 spaces to indent. The Ruby standard is 2.