Error generated after calling form_for

rubyonrails-talk
1

Hello list,

I’m a fairly nooby Rails developer of very little brain, and this error has had me confused for the last several hours.

It’s a very simple (unfinished) Rails app. It has a model called Tasks. It has a very basic routes.rb

resources :tasks

root :to => ‘tasks#index’

A vanilla controller (create action not properly defined yet because that would have been next on the list when I ran into this problem)

class TasksController < ApplicationController

def index

@tasks = Tasks.all

end

def new

@task = Tasks.new

end

def create

end

end

And a view for the /tasks/new action

Create new task

<%= form_for @task do |form| %>

<%= lots of form. blah blah here… %>

<% end %>

And when the view is rendered I get the following error:

undefined method `tasks_index_path' for #<#<Class:0x000000020c04e8>:0x000000020b74d8>

Extracted source (around line #2):

1: <h1>Create new task</h1>
2: <%= form_for @task do |form| %>

And here are the top few lines of the stack trace:

actionpack (3.0.0) lib/action_dispatch/routing/polymorphic_routes.rb:114:in `polymorphic_url'
actionpack (3.0.0) lib/action_dispatch/routing/polymorphic_routes.rb:120:in `polymorphic_path'
actionpack (3.0.0) lib/action_view/helpers/form_helper.rb:335:in `apply_form_for_options!'
actionpack (3.0.0) lib/action_view/helpers/form_helper.rb:307:in `form_for'
app/views/tasks/new.html.erb:2:in `_app_views_tasks_new_html_erb__194514136627382544_17145340__4434388515179536201'

I don’t really understand where “tasks_index_path” came from or why form_for has bombed out so spectacularly, especially given how simple the code is right now. Can anyone point me at what I might be doing wrong?

Oh yes, it’s rails 3.0.0 on ruby 1.9.2 running on Ubuntu 10.04.

Thanks,

Mark

2

Hello list,

Hi Mark,

I'm a fairly nooby Rails developer of very little brain, and this error has had me confused for the last several hours.

It's a very simple (unfinished) Rails app. It has a model called Tasks. It has a very basic routes.rb

  resources :tasks   root :to => 'tasks#index'

A vanilla controller (create action not properly defined yet because that would have been next on the list when I ran into this problem)

class TasksController < ApplicationController

  def index     @tasks = Tasks.all   end

  def new     @task = Tasks.new   end

  def create   end

end

models are always singular in rails. Try the following:

   def index      @tasks = Task.all    end

   def new      @task = Task.new    end

That should help.

Regards, Max.

3

Mmm, perhaps you meant that all models should be singular in rails. Mine weren’t! However after a couple of quick search-and-replaces I had a singular Task model and suddenly the form_for error went away. Interesting side-effect. Maybe warnings about pluralised models in the docs need to be in really BIG RED LETTERS so that idiots like me will notice them.

Anyway, thanks for the reply.

Mark

4

Mark Weston wrote:

That should help.

Regards, Max.

Mmm, perhaps you meant that all models *should* be singular in rails. Mine weren't! However after a couple of quick search-and-replaces I had a singular Task model and suddenly the form_for error went away. Interesting side-effect. Maybe warnings about pluralised models in the docs need to be in really BIG RED LETTERS so that idiots like me will notice them.

Remember: try to name your classes after what they actually represent! A Task object represents one Task, so you really *shouldn't* call it Tasks.

Anyway, thanks for the reply.

Mark

Best,