Ruby on Rails

Hi all!

I have 3 models: user, post, comment

User has_many :posts, :comments  Post belongs_to :user, has_many :comments  Comments belongs_to :user, post

So for creating post i have action create

def create      @post = Post.new(post_params)        if @post.save        redirect_to @post      else        render 'new'      end  end

Now if following the rules of relations between Post and Comment, for creating a comment i have next action in CommentController:

def create      @post = Post.find(params[:post_id])      @comment = @post.comments.create(comment_params)      redirect_to post_path(@post)  end

My question is: How rewrite the actions if i want create post and comment from user?

if i try to create Comment from User, i create next action (don't know am i right?)

def create      @user = User.find(params[:user_id])      @post = user.posts.build(post_params)      if @post.save        flash[:success] = "Post created!"        redirect_to post_path      else        flash[:errors] = "Post not created!"        render 'new'      end  end

How create a comment from user, that will be in relations with post? i mean comment must have user_id and post_id?

tnx 4 help