title: Nested Resorces :forbdden attributes
body: <p>I am new in rails and I am getting <code>ActiveModel::ForbiddenAttributesError</code>. This is my controller for nested resource:</p>
  
  <pre><code>class PostsController &lt; ApplicationController
    respond_to :html, :xml, :json
  
    def index
      @post=Post.all  
    end
  
    def new
      @user = User.find(params[:user_id])
      @post = @user.posts.build
      respond_with(@post)
    end
  
    def create
      debugger
      @user = User.find(params[:user_id])
      @post = @user.posts.build(params[:post])
      if @post.save
        redirect_to user_posts_path
      else
        render 'new'
      end
    end
  
    def post_params
      params.require(:post).permit(:title, :description, {:user_ids =&gt;[]})
    end
  end
  </code></pre>