Question

在完成REST Client时，使用路由从JS检查，在后台（DelayedJob）从此外部API获取项目。路由部分工作正常，但如何从视图中重用相同的@items_status，以便Ajax实际上可以加载项并在完成后插入它们？

您可以即时投放的实时应用：http://runnable.com/VXIdQ6KuRrYPdhKs/rest-client-ajax（https://gist.github.com/dt1973/b57d84bf39a75ea47e9b）

index.html.erb

<!-- THIS ALWAYS RETURNS FALSE EVEN WHEN TRUE -->

<% if @items_status %>
  <div class="products">
    <% @products.each do |product| %>
      <div class="product">
        <%= link_to product.name, product.url %>
      </div>
    <% end %>
  </div>
<% else %>
  <div class="products processing">
    <p>Currently fetching.. come back later</p>

    <!-- Fetch via Ajax later -->

  </div>
<% end %>

check_items_loaded.js.erb

<!-- This seems to return true properly though -->

alert("<%= @items_status %>");

的routes.rb

get '/check_items_loaded', to: 'main#check_items_loaded', as: :check_items_loaded

main_controller.rb

class MainController < ApplicationController
  def index
    # Delay fetching
    @products = Affiliate.delay.fetch
  end

  def check_items_loaded
    @items_status = Affiliate.where(url: params[:url]).exists?
    respond_to do |wants|
      wants.js
    end
  end
end

affiliate.rb

require "rest_client"

class Affiliate < ActiveRecord::Base
  def self.fetch
    response = RestClient::Request.execute(
      :method => :get,
      :url => "http://api.shopstyle.com/api/v2/products?pid=uid7849-6112293-28&fts=women&offset=0&limit=10"
    )

    @products = JSON.parse(response)["products"].map do |product|
      product = OpenStruct.new(product)
      affiliate = Affiliate.find_or_create_by(:name => product.name, :url => product.url)
      affiliate.save
    end
  end
end

Answer 1

您必须重复使用用于检查项目是否被提取的路由，而不是视图中的实例@items_status。

在您的Ajax部分中，您基本上必须继续查询路由以检查是否已完成提取，并且当它完成时，您必须向另一个路由发出请求以将获取的项目返回到页面。

所以制作另一条路线，如get_items_fetched，我认为最好的回应是包含这些项目的json数据。例如：

def get_fetched_items
  respond_to do |format|
    format.json do 
      render json: @products
    end
  end
end

您应该在/get_items_fetched.json获取json数据。

更新1：

获取商品状态和商品的正确方法如下：

AJAX部分：

首先将setTimeout更改为setInterval，因此它会自动保持对item_status的轮询。但是如果您有自己的理由使用setTimeout，那么您可以忽略它。
```
 poll: function() {
   console.log('Ran `poll`');
   // Change here, setTimeout to setInterval.
   window.pollInterval = setInterval(this.request, 3000);
 },
```

其次检查为轮询请求返回的item_status，不要在错误部分重试。

request: function() {

  console.log('Ran `request`');
  $.ajax({
    url: "/check_items_loaded",
    type: "GET",

    // Change here ! Added the checking of the item status returned.
    // Why ? Previsouly it wasn't checking at all. So if the request was
    // successful, it meant the items_status was also true.
    success: function(data){
      // Note if the data has the json MIME type, it'll be automatically
      // converted to a JavaScript object.
      if(data.item_status == true) {
        console.log('Items now ready');
        $.restClient.addItems();

        // Now you don't have to poll anymore, so clear interval.
        clearInterval(window.pollInterval);
      }
      else 
        console.log('Fetching going on ...');
    },
    error: function() {
      console.log('Request was not completed successfully.');
    }
  });
},

接下来，解析您在addItems的响应中获得的HTML。默认情况下，如果响应是HTML，则会将其作为纯文本提供。

addItems: function() {
  console.log('Ran `addItems`');

  var dataUrl = '/';

  $.get(dataUrl, function(data) {
    // Parsing it first.
    var html = $.parseHTML(data);
    $(html).find('.product').appendTo($('body'));
    console.log(html);
  });

  console.log('New items were added');
}

现在在后端，/check_items_done路线部分：

 def check_items_loaded
  @items_status = Affiliate.where(url: params[:url]).exists?
  render json: {item_status: @item_status}
 end

完成项目后，使用路线从视图中进行检查

1 个答案: