How do I call all comments for a post (workout in this case) where workout.user_id == current_user.id?

问题

I have created a Ruby on Rails app where users can record their workouts and other users can comment on those workouts. I am using a Dashboard resource to aggregate information for current_user. I am trying to display recent comments on a current_user's workouts but can't seem to figure out how to do this correctly. I think I need a named_scope which I am not great at yet.

I essentially want the app to loop through the comments table but only return comments on Workouts where workout.user_id == to current_user.id.

/views/dashboard/index.html.erb

<% @comments.each do |comment| %> 
  <%= link_to (comment.user.username), comment.user %><br/>
  <%= time_ago_in_words(comment.created_at) %><br/>
  <%= link_to (comment.workout.title), comment.workout %><br/>
<% end %>

dashboard_controller.rb

def index
  @comments = Comment.all(:order => "created_at DESC", :limit => 10)
  @workouts = Workout.all(:order => "created_at DESC", :limit => 10) 
end

*I don't think I need the @workouts line in their but put it anyway.

回答1:

Assuming that you have the models setup properly, here's something you can try:

class Comment < ActiveRecord::Base
  named_scope :for_user, lambda { |user| { :joins => :workout, :conditions => ["workouts.user_id = ?", user.id] } }
  named_scope :order, lambda { |order| { :order => order } }
  named_scope :limit, lambda { |limit| { :limit => limit } }
end

class DashboardsController < ApplicationController
  def index
    @comments = Comment.for_user(current_user).order("created_at DESC").limit(10)
  end
end

回答2:

The proper way to do is to put relations between your models, i.e. comment and workout. Each workout can have many comments, and each comment belongs to a workout. So:

class Comment < ActiveRecord::Base
      belongs_to :workout

      # rest of the model definitions
end

and

class Workout < ActiveRecord::Base
      has_many :comments

      # rest of the model definitions
end

Once you set it up like this, then you can call:

<% @workout.comments do |comment| %> 
   <!-- print comment here -->
<% end %>

You can follow the example here.

来源：https://stackoverflow.com/questions/4311074/how-do-i-call-all-comments-for-a-post-workout-in-this-case-where-workout-user

标签

ruby-on-rails

ruby

named-scope