Question

Following Hartl’s railstutorial and I changed my error-messages partial to work with other objects http://ruby.railstutorial.org/chapters/updating-showing-and-deleting-users#sec:edit_form.

After changing all my @user to object and passing :object => f.object when I render the partial, I get this error when I try to load up my sign up page:

NameError in Users#new: undefined local variable or method 'f'

and it points to this line

<%= render 'shared/error_messages', :object => f.object %>

Any advice?

new.html.erb

<div id="mainlogo"><%= image_tag("sample_logo.png", :alt => "Sample Title", 
                                                    :class =>"round")%></div>

    <div id="errors_new">
    <%= render 'shared/error_messages', :object => f.object %>
    </div>

    <div id="signup_spacer"></div>

<div id="signupcontainer_new" class="round">
<h1>Sign Up</h1>
<p>It's free</p>

<div id="signupform_new">
    <%= render :partial => 'users/usersignup' %>
</div>

</div>

_error_messages.html.erb

<% if object.errors.any? %>
  <div id="error_explanation" class="round">


  <% object.errors.full_messages.each do |msg| %>
  <h2><%= msg %></h2>
     <% end %>


  </div>
<% end %>

_usersignup.html.erb

<%= form_for(@user) do |f| %>
  <div class="field">
    <%= f.label :username %><br />
    <%= f.text_field :name %>
  </div>
...
<% end %>

Answer 1

f.object is only valid inside the block that defines f, which is now in the form partial.

The line needs to be within the form_for block in the form partial as in the tutorial.

The tutorial also creates a partial for just the fields, where that line can go.