红宝石逻辑，用于获取每个列表的第一张图片

Question

I have a listing model . Each listing has many images. So in my index page I want to display all listings and the first image of each listing. So in controller I first fetch all listings which has all fields like :name , : description, etc . Now for the images part is where am stuck. How can I properly add the : custom_url field with the image url in each room using ruby code?

(NB: I am using angular on front end so this is just for the json and dont want to add a seperate field in database for the first image)

So here is the controller code

 def search
    @listings = Listing.all


      custom_url = listing.photos[0].image_url(:medium)

    respond_to do |format|
      format.html
      format.json { render json: {listings: @listings} }
    end
  end

Answer 1

In the Listing model add a method that gets the image url and call it custom_url

Listing.rb

def custom_url
    photos.first.image_url(:medium)
end

Then in the render_json include the method custom_url :

def search
  @listings = Listing.all
  listings_json = @listings.as_json({methods: :custom_url}

  respond_to do |format|
    format.json { render json: {listings: listings_json }
  end
end