如何构建同时返回用户帖子和帖子类别的查询？

Question

In my controller's index action:

@posts = current_user.posts.process_and_return_posts  

In the model:

class Post < ActiveRecord::Base
  belongs_to :user
  belongs_to :category

  def self.process_and_return_posts
    # doing some cleanup
    # return posts
  end
end

In the view I will display the posts by category, I wonder how I should structure the query and in what type of collection I want the posts?

I need the collection to contain both the Category objects and the Post objects (as I will order them when iterating over them in the view).

Answer 1

I guess what you want is

group_by { |post| post.category }

This way you can use in your view

Post.process_and_return_posts.keys.each do |category|
  category.posts ...
end

This should also work in combination with your association

current_user.posts.process_and_return_posts.keys.each do |category|
  category.posts ...
end

Answer 2

It's important to notice that current_user.posts actually returns Array object filled with Post objects, and not a post object.

So you should monkey patch process_and_return_posts method in Enumerable module instead of Post class.

You can monkey patch in many ways on Rails, but my favorite way is to put all the monkey patched code in one place, so that I know what's been monkey patched before.

From your rails directory, inside config/initializers , create a directory called extensions . This is where you can put all your monkey patched code. Inside config/initializers/extensions , create a Ruby file called, enumerables.rb so that you know later that this code contains code for enumerables.

In config/initializers/extensions/enumerables.rb ,

module Enumerable
  def process_and_return_posts
    # your code here.
  end
end

Be sure to restart your rails server, whenever you update anything in initializers .