NoMethodError in Discussions#new

问题

Can anyone help me to fix this?Thanks in advance! I get the following error:

NoMethodError in Discussions#new
Showing C:/Users/punitha/aggregator/app/views/discussions/_form.html.erb where line #1 raised:

undefined method `discussions_index_path' for #<#<Class:0x4375758>:0x437d6d8>

Extracted source (around line #1):

1  <%= form_for @discussions do |f| %>
2  <% if @discussions.errors.any? %>
3        <div id="error_explanation">
4        <h2><%= pluralize(@discussions.errors.count, "error") %> prohibited

Trace of template inclusion: app/views/discussions/new.html.erb

Rails.root: C:/Users/punitha/aggregator

Application Trace | Framework Trace | Full Trace
app/views/discussions/_form.html.erb:1:in `_app_views_discussions__form_html_erb___1058370717_35436840'
app/views/discussions/new.html.erb:3:in `_app_views_discussions_new_html_erb__298093787_35389404'

And the file _form.html.erb is

<%= form_for @discussions do |f| %>
<% if @discussions.errors.any? %>
 <div id="error_explanation">
 <h2><%= pluralize(@discussions.errors.count, "error") %> prohibited
     this discussion from being saved:</h2>
 <ul>
    <% @discussions.errors.full_messages.each do |msg| %>
    <li><%= msg %></li>
    <% end %>
    </ul>
</div>
 <% end %>
 <p>
<%= f.label :source_url %><br>
<%= f.text_field :source_url %>
  </p>

 <p>
<%= f.label :discussion_id %><br>
<%= f.text_area :discussion_id %>
 </p>

<p>
<%= f.label :discussion_msg %><br>
<%= f.text_area :discussion_msg %>
</p>

 <p>
 <%= f.label :discussion_type %><br>
 <%= f.text_field :discussion_type %>
 </p>

<p>
<%= f.label :discussion_link %><br>
<%= f.text_area :discussion_link %>
</p>
<p>
<%= f.label :discussion_thumb %><br>
<%= f.text_area :discussion_thumb %>
 </p>
<p>
<%= f.label :discussion_permalink %><br>
<%= f.text_area :discussion_permalink %>
</p>

<p>
<%= f.label :discussion_likecount %><br>
<%= f.number_field :discussion_likecount%>
 </p>

<p>
<%= f.label :comment %><br>
<%= f.text_area :comment%>
</p>
<p>
<%= f.label :source_id %><br>
<%= f.number_field :source_id%>
</p>

 <p>
<%= f.submit %>
 </p>
 <% end %>

And my app/views/discussions/new.html.erb is,

<h1>New discussion</h1>

<%= render 'form' %>

<%= link_to 'Back', discussions_path %>

routes.rb file

Aggregator::Application.routes.draw do
get "welcome/index"
root 'welcome#index'


resources:discussions do
resources :comments
end
end

回答1:

You're form_for is set to an array (@discussions) when it should be to a single instance (@discussion).

In your DiscussionsController's new method, ensure you have something along the following:

@discussion = Discussion.new

Then, in your form, change your current form_for expression to:

form_for @discussion

See if that clears your error.

回答2:

First of all you should correct your typo mistake in routes.rb.

It should looks like (I have added a space between resources and :discussions):

Aggregator::Application.routes.draw do
  get "welcome/index"
  root 'welcome#index'

  resources :discussions do
    resources :comments
  end
end

As Craig Kaminsky said, it seems you are having @discussions as an array of discussion records.'

In your controller's action new, you should initialize your object as:

@discussion = Discussion.new

And you form should use same instance variable (@discussion)

  <%= form_for @discussion do |f| %>
    <% if @discussion.errors.any? %>
        <div id="error_explanation">
        <h2><%= pluralize(@discussion.errors.count, "error") %> prohibited
        ...
    <% end %>
    ...
    ...
  <% end %>

来源：https://stackoverflow.com/questions/22143309/nomethoderror-in-discussionsnew

标签

ruby-on-rails

nomethoderror