ruby-on-rails - Rails paperclip static files with absolute url

Question

I have a model with one paperclip attachment :image

Model:

class HomeScreen < ActiveRecord::Base
  before_create { !HomeScreen.has_record? }
  validates :image, :attachment_presence => true
  attr_accessible :image
  has_attached_file :image

  def self.has_record?
    if HomeScreen.last
      true
    else
      false
    end
  end
end

show method of my conttroller should return image with relative path but json should return absolute url with domain, how can I do that?

Controller:

class HomeScreenController < ApplicationController
  # GET /home_screen
  def show    
    @home_screen = HomeScreen.last

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

Answer 1

根据github issue，您可以执行以下操作：

image_uri = URI.join(request.url, @home_screen.image.url)

这将是一个URI对象，可以String用它的.to_s

Answer 2

根据相同的github 问题，它使用起来更干净，ActionController::Base.asset_host因此会产生助手：

  def add_host_prefix(url)
    URI.join(ActionController::Base.asset_host, url)
  end

这假设您在每个/config/environments/<environment>.rb文件中都有以下内容：

Appname::Application.configure do

  # ....

  config.action_controller.asset_host = 'http://localhost:3000' # Locally

  # ....

end