form_for method undefined

Question

I read a book called 'Rails 3 in Action' and made two pages: 'index' and 'new', set routes.rb:

root :to => 'projects#index'
match '/new', to:'projects#new'

and projects_controller:

def new
  @project = Project.new
end

def create
  @project = Project.new(parmas[:project])
  @project.save
  flash[:notice] = "Project has been created"
  redirect_to @project
end

and view files:

index.html.erb

<%= link_to "new", new_path %>

This works correctly, because I end up at localhost:3000/new, but the problem is:

<%= form_for(@project) do |f| %>

This results in:

undefined method `projects_path' for #<#:0x416b830>

Where is projects_path? When I print <%= root_path %>, I get /, but <%= projects_path %> gives error undefined method.

How do I define a method projects_path? Root is not projects_path?

Answer 1

You should define resource for project in routes.rb

resources :projects

This will generate helper projects_path and a banch of others

Answer 2

Remove the line match '/new', to:'projects#new' from routes.rb and add this:

resources :projects

Answer 3

The path used to create new projects is a HTTP post to the index URL of "/projects". You need to specify this route:

post "/projects", :controller => "projects", :action => "create", :as => "projects"

This will generate a projects_path, which is the helper method your form_for is looking for.

As others have said, you should probably use resources :projects instead. If you're interested in only creating a subset of the seven RESTful routes created by default, you can use :only:

resources :projects, :only => %w(index new create)