undefined method `premails_path' for #<#<Class:0x4fa8530>:0x52c1ec8> - ruby-on-rails

Question

I am trying to add a pre-launch sign-up email form on my pages index view. I made a form on my view, then created a controller, then made the model and table and ran the migration. Is this the right way to do it?
I am getting the following error:
NoMethodError in Pages#index
undefined method `premails_path' for #<#<Class:0x4fa8530>:0x52c1ec8>
on line:
<%= form_for(#premail) do |f| %>
from
<%= form_for(#premail) do |f| %>
<% if #premail.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(#premail.errors.count, "error") %> prohibited this link from being saved:</h2>
My pages controller has the following:
class PagesController < ApplicationController
def index
#premail = Premail.new
end
end
My pages index view has the following:
<%= form_for(#premail) do |f| %>
<% if #premail.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(#premail.errors.count, "error") %> prohibited this link from being saved:</h2>
<ul>
<% #premail.errors.full_messages.each do |msg| %>
<li><%= msg %></li>
<% end %>
</ul>
</div>
<% end %>
<div class="field">
<%= f.label :Email %><br />
<%= f.text_field :Email %>
</div>
<div class="actions">
<%= f.submit %>
</div>
<% end %>
I generated the following model:
class Premail < ActiveRecord::Base
end
and the following db migrate table:
class CreatePremails < ActiveRecord::Migration
def change
create_table :premails do |t|
t.text :email
t.timestamps
end
end
end
What can I do differently to make this work?

Answer 1

Because you're loading this form on Pages#index, you'll benefit from using the url: argument like this:
<%= form_for #premail, url: pages_index_path do |f| %>
Update
From the Rails guide:
Resource-oriented style
In the examples just shown, although not indicated explicitly, we
still need to use the :url option in order to specify where the form
is going to be sent. However, further simplification is possible if
the record passed to form_for is a resource, i.e. it corresponds to a
set of RESTful routes, e.g. defined using the resources method in
config/routes.rb. In this case Rails will simply infer the appropriate
URL from the record itself. For example,
<%= form_for #post do |f| %> ... <% end %> is then equivalent to
something like:
<%= form_for #post, as: :post, url: post_path(#post), method: :patch,
html: { class: "edit_post", id: "edit_post_45" } do |f| %> ... <%
end %>
As you're using #premails instance var (which is an instance of the Premail class), your form_for helper will be trying to use a premails path. To use a pages path (as per your question), you'll need to manually set the url option