Rails-路由错误-从另一个模型调用模型

Question

Question: My goal is to list projects under the user's page, and have comment box render under each project that is listed on this user page. But when I do try to render the comment box form, I get a routing error. I know this is because it is not being able to pull out the ID of the project. My guess is something to do with the controller but have not figured out. Does somebody know how I can solve this?

Routing Error
No route matches {:controller=>"comments", :format=>nil, :project_id=>#<Project id: nil...>}

For my application, I have created models and controllers for Users, Projects, and Comments. Comments belong to Projects and Projects belong to Users

user.rb

has_many :projects

project.rb

has_many :comments
belongs_to :user

comment.rb

belongs_to :project

routes.rb

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

resources :projects do
  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]) do |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 from the redirect above

NoMethodError in CommentsController#create
undefined method `user'

Answer 1

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]) do |f| %>
...

You have to pass the project to form partial.

Hope this helps!