Rails - Routing Error - Calling a model from another model -

question: goal list projects under user's page, , have comment box render under each project listed on user page. when try render comment box form, routing error. know because not being able pull out id of project. guess controller have not figured out. know how can solve this?

routing error no route matches {:controller=>"comments", :format=>nil, :project_id=>#<project id: nil...>} 

for application, have created models , controllers users, projects, , comments. comments belong projects , projects belong users

user.rb

has_many :projects 

project.rb

has_many :comments belongs_to :user 

comment.rb

belongs_to :project 

routes.rb

resources :users   resources :projects     resources :comments   end end  resources :projects   resources :comments  end  resources: comments 

view/users/projects.html.erb

<%= render @projects %> 

view/projects/_project.html.erb

<%= project.content %> <%= render 'comments/form' %> 

view/comments/_form.html.erb

<%= form_for([@project, @project.comments.build]) |f| %>     <div class="field">     <%= f.text_area :content, :class => "span12", :rows => "3" %>     </div>      <%= f.hidden_field :user_id, :value => current_user.id %>      <div class="actions">     <%= f.submit "add comment", :class => "btn btn-header" %>     </div> <% end %> 

comments_controller.rb

def create   @project = project.find(params[:project_id])   @comment = @project.comments.create!(params[:comment])    if @comment.save     redirect_to projects_user_path(@project.user)   end    end 

error redirect above

nomethoderror in commentscontroller#create undefined method `user' 

try this:

view/projects/_project.html.erb

<%= project.content %> <%= render 'comments/form', project: project %> 

view/comments/_form.html.erb

<%= form_for([project, project.comments.build]) |f| %> ... 

you have pass project form partial.

hope helps!