Rails javascript轮询

我试图在我的应用程序中实现javascript轮询，但遇到了一些问题。我非常赞同这一点。我的问题是试图预先准备任何新发现的数据。它会预先处理所有新旧数据，如果没有找到任何新数据，它只会预先处理所有旧数据。我的另一个问题是，我的setTimeout只被调用一次，即使在我尝试像railscast中显示的那样保持轮询之后也是如此。下面是我的代码。我做错了什么

polling.js

var InboxPoller;

InboxPoller = {
  poll: function() {
    return setTimeout(this.request, 5000);
  },
  request: function() {
    return $.getScript($('.inbox_wrap').data('url'), {
      after: function() {
        $('.conversation').last().data('id')
      }
    });
  }
};

$(function() {
  if ($('.inbox_wrap').length > 0) {
    return InboxPoller.poll();
  }
});

polling.js.erb

$(".inbox_wrap").prepend("<%= escape_javascript(render @conversations, :locals => {:conversation => @conversation}) %>");
InboxPoller.poll();

class ConversationsController < ApplicationController
    before_filter :authenticate_member!
    helper_method :mailbox, :conversation

    def index
        @messages_count = current_member.mailbox.inbox({:read => false}).count
        @conversations = current_member.mailbox.inbox.order('created_at desc').page(params[:page]).per_page(15)
    end

    def polling 
        @conversations = current_member.mailbox.inbox.where('conversation_id > ?', params[:after].to_i)
    end 

    def show
        @receipts = conversation.receipts_for(current_member).order('created_at desc').page(params[:page]).per_page(20)

        render :action => :show
        @receipts.mark_as_read 
    end

    def create
        recipient_emails = conversation_params(:recipients).split(',').take(14)
        recipients = Member.where(user_name: recipient_emails).all

        @conversation = current_member.send_message(recipients, *conversation_params(:body, :subject)).conversation

        respond_to do |format|
          format.html { redirect_to conversation_path(conversation) }
          format.js
        end  
    end

    def reply
        @receipts = conversation.receipts_for(current_member).order('created_at desc').page(params[:page]).per_page(20)
        @receipt = current_member.reply_to_conversation(conversation, *message_params(:body, :subject))

        respond_to do |format|
          format.html { conversation_path(conversation) }
          format.js 
        end
    end

    private

      def mailbox
          @mailbox ||= current_member.mailbox
      end

      def conversation
          @conversation ||= mailbox.conversations.find(params[:id])
      end

      def conversation_params(*keys)
          fetch_params(:conversation, *keys)
      end

      def message_params(*keys)
          fetch_params(:message, *keys)
      end

      def fetch_params(key, *subkeys)
          params[key].instance_eval do
            case subkeys.size
              when 0 then self
              when 1 then self[subkeys.first]
              else subkeys.map{|k| self[k] }
            end
          end
      end

      def check_current_subject_in_conversation
          if !conversation.is_participant?(current_member)
            redirect_to conversations_path
          end
      end

end

<%= content_tag :div, class: "inbox_wrap", data: {url: polling_conversations_url} do %>
    <%= render partial: "conversations/conversation", :collection => @conversations, :as => :conversation %>
<% end %>

<div id="conv_<%= conversation.id %>_<%= current_member.id %>" class="conversation" data-id="<%= conversation.id %>">

    <div class="conv_body">
        <%= conversation.last_message.body %>
    </div>

    <div class="conv_time">
        <%= conversation.updated_at.localtime.strftime("%a, %m/%e %I:%M%P") %>
    </div>

</div>

$（“.inbox_wrap”）.prepend（“{:conversation=>@conversation}）%>”；
InboxPoller.poll（）；

对话\u controller.rb

$(".inbox_wrap").prepend("<%= escape_javascript(render @conversations, :locals => {:conversation => @conversation}) %>");
InboxPoller.poll();

class ConversationsController < ApplicationController
    before_filter :authenticate_member!
    helper_method :mailbox, :conversation

    def index
        @messages_count = current_member.mailbox.inbox({:read => false}).count
        @conversations = current_member.mailbox.inbox.order('created_at desc').page(params[:page]).per_page(15)
    end

    def polling 
        @conversations = current_member.mailbox.inbox.where('conversation_id > ?', params[:after].to_i)
    end 

    def show
        @receipts = conversation.receipts_for(current_member).order('created_at desc').page(params[:page]).per_page(20)

        render :action => :show
        @receipts.mark_as_read 
    end

    def create
        recipient_emails = conversation_params(:recipients).split(',').take(14)
        recipients = Member.where(user_name: recipient_emails).all

        @conversation = current_member.send_message(recipients, *conversation_params(:body, :subject)).conversation

        respond_to do |format|
          format.html { redirect_to conversation_path(conversation) }
          format.js
        end  
    end

    def reply
        @receipts = conversation.receipts_for(current_member).order('created_at desc').page(params[:page]).per_page(20)
        @receipt = current_member.reply_to_conversation(conversation, *message_params(:body, :subject))

        respond_to do |format|
          format.html { conversation_path(conversation) }
          format.js 
        end
    end

    private

      def mailbox
          @mailbox ||= current_member.mailbox
      end

      def conversation
          @conversation ||= mailbox.conversations.find(params[:id])
      end

      def conversation_params(*keys)
          fetch_params(:conversation, *keys)
      end

      def message_params(*keys)
          fetch_params(:message, *keys)
      end

      def fetch_params(key, *subkeys)
          params[key].instance_eval do
            case subkeys.size
              when 0 then self
              when 1 then self[subkeys.first]
              else subkeys.map{|k| self[k] }
            end
          end
      end

      def check_current_subject_in_conversation
          if !conversation.is_participant?(current_member)
            redirect_to conversations_path
          end
      end

end

<%= content_tag :div, class: "inbox_wrap", data: {url: polling_conversations_url} do %>
    <%= render partial: "conversations/conversation", :collection => @conversations, :as => :conversation %>
<% end %>

<div id="conv_<%= conversation.id %>_<%= current_member.id %>" class="conversation" data-id="<%= conversation.id %>">

    <div class="conv_body">
        <%= conversation.last_message.body %>
    </div>

    <div class="conv_time">
        <%= conversation.updated_at.localtime.strftime("%a, %m/%e %I:%M%P") %>
    </div>

</div>

类会话控制器false}）.count
@对话=当前成员.邮箱.收件箱.订单（'created_at desc'）。页面（参数[：页面]）。每页（15）
结束
def轮询
@conversations=当前成员.mailbox.inbox.where（'conversations\u id>？'，参数[：after].\u i）
结束
def秀
@收据=对话。当前成员的收据。订单（'created_at desc'）。页面（参数[：page]）。每页（20）
呈现：操作=>：显示
@收据。标记为已读
结束
def创建
收件人电子邮件=对话参数（：收件人）。拆分（'，'）。获取（14）
收件人=成员。其中（用户名：收件人电子邮件）。全部
@对话=当前成员。发送消息（收件人，*对话参数（：正文，：主题））。对话
回应待办事项|格式|
format.html{重定向到对话路径（对话）}
format.js
结束
结束
def回复
@收据=对话。当前成员的收据。订单（'created_at desc'）。页面（参数[：page]）。每页（20）
@接收=当前成员。回复对话（对话，*消息参数（：正文，：主题））
回应待办事项|格式|
format.html{conversation_path（conversation）}
format.js
结束
结束
私有的
def邮箱
@邮箱| |=当前成员。邮箱
结束
def对话
@对话| |=邮箱.对话.查找（参数[：id]）
结束
def对话参数（*键）
获取参数（：对话，*键）
结束
def消息参数（*键）
获取参数（：消息，*键）
结束
def fetch_参数（键，*子键）
参数[key]。实例\u评估do
大小写子键
当0时，则为self
当1时，则为self[子键.first]
else子键.map{| k | self[k]}
结束
结束
结束
def检查对话中的当前主题
如果！对话。是否参与？（当前成员）
重定向到对话路径
结束
结束
结束

index.html.erb

$(".inbox_wrap").prepend("<%= escape_javascript(render @conversations, :locals => {:conversation => @conversation}) %>");
InboxPoller.poll();

class ConversationsController < ApplicationController
    before_filter :authenticate_member!
    helper_method :mailbox, :conversation

    def index
        @messages_count = current_member.mailbox.inbox({:read => false}).count
        @conversations = current_member.mailbox.inbox.order('created_at desc').page(params[:page]).per_page(15)
    end

    def polling 
        @conversations = current_member.mailbox.inbox.where('conversation_id > ?', params[:after].to_i)
    end 

    def show
        @receipts = conversation.receipts_for(current_member).order('created_at desc').page(params[:page]).per_page(20)

        render :action => :show
        @receipts.mark_as_read 
    end

    def create
        recipient_emails = conversation_params(:recipients).split(',').take(14)
        recipients = Member.where(user_name: recipient_emails).all

        @conversation = current_member.send_message(recipients, *conversation_params(:body, :subject)).conversation

        respond_to do |format|
          format.html { redirect_to conversation_path(conversation) }
          format.js
        end  
    end

    def reply
        @receipts = conversation.receipts_for(current_member).order('created_at desc').page(params[:page]).per_page(20)
        @receipt = current_member.reply_to_conversation(conversation, *message_params(:body, :subject))

        respond_to do |format|
          format.html { conversation_path(conversation) }
          format.js 
        end
    end

    private

      def mailbox
          @mailbox ||= current_member.mailbox
      end

      def conversation
          @conversation ||= mailbox.conversations.find(params[:id])
      end

      def conversation_params(*keys)
          fetch_params(:conversation, *keys)
      end

      def message_params(*keys)
          fetch_params(:message, *keys)
      end

      def fetch_params(key, *subkeys)
          params[key].instance_eval do
            case subkeys.size
              when 0 then self
              when 1 then self[subkeys.first]
              else subkeys.map{|k| self[k] }
            end
          end
      end

      def check_current_subject_in_conversation
          if !conversation.is_participant?(current_member)
            redirect_to conversations_path
          end
      end

end

<%= content_tag :div, class: "inbox_wrap", data: {url: polling_conversations_url} do %>
    <%= render partial: "conversations/conversation", :collection => @conversations, :as => :conversation %>
<% end %>

<div id="conv_<%= conversation.id %>_<%= current_member.id %>" class="conversation" data-id="<%= conversation.id %>">

    <div class="conv_body">
        <%= conversation.last_message.body %>
    </div>

    <div class="conv_time">
        <%= conversation.updated_at.localtime.strftime("%a, %m/%e %I:%M%P") %>
    </div>

</div>

@对话，：as=>：对话%>

\u conversation.html.erb

$(".inbox_wrap").prepend("<%= escape_javascript(render @conversations, :locals => {:conversation => @conversation}) %>");
InboxPoller.poll();

class ConversationsController < ApplicationController
    before_filter :authenticate_member!
    helper_method :mailbox, :conversation

    def index
        @messages_count = current_member.mailbox.inbox({:read => false}).count
        @conversations = current_member.mailbox.inbox.order('created_at desc').page(params[:page]).per_page(15)
    end

    def polling 
        @conversations = current_member.mailbox.inbox.where('conversation_id > ?', params[:after].to_i)
    end 

    def show
        @receipts = conversation.receipts_for(current_member).order('created_at desc').page(params[:page]).per_page(20)

        render :action => :show
        @receipts.mark_as_read 
    end

    def create
        recipient_emails = conversation_params(:recipients).split(',').take(14)
        recipients = Member.where(user_name: recipient_emails).all

        @conversation = current_member.send_message(recipients, *conversation_params(:body, :subject)).conversation

        respond_to do |format|
          format.html { redirect_to conversation_path(conversation) }
          format.js
        end  
    end

    def reply
        @receipts = conversation.receipts_for(current_member).order('created_at desc').page(params[:page]).per_page(20)
        @receipt = current_member.reply_to_conversation(conversation, *message_params(:body, :subject))

        respond_to do |format|
          format.html { conversation_path(conversation) }
          format.js 
        end
    end

    private

      def mailbox
          @mailbox ||= current_member.mailbox
      end

      def conversation
          @conversation ||= mailbox.conversations.find(params[:id])
      end

      def conversation_params(*keys)
          fetch_params(:conversation, *keys)
      end

      def message_params(*keys)
          fetch_params(:message, *keys)
      end

      def fetch_params(key, *subkeys)
          params[key].instance_eval do
            case subkeys.size
              when 0 then self
              when 1 then self[subkeys.first]
              else subkeys.map{|k| self[k] }
            end
          end
      end

      def check_current_subject_in_conversation
          if !conversation.is_participant?(current_member)
            redirect_to conversations_path
          end
      end

end

<%= content_tag :div, class: "inbox_wrap", data: {url: polling_conversations_url} do %>
    <%= render partial: "conversations/conversation", :collection => @conversations, :as => :conversation %>
<% end %>

<div id="conv_<%= conversation.id %>_<%= current_member.id %>" class="conversation" data-id="<%= conversation.id %>">

    <div class="conv_body">
        <%= conversation.last_message.body %>
    </div>

    <div class="conv_time">
        <%= conversation.updated_at.localtime.strftime("%a, %m/%e %I:%M%P") %>
    </div>

</div>

---

Javascript轮询效率极低-基本上每隔几秒钟向服务器发送请求以侦听“更新”。即使如此，在许多情况下，更新将是完整的文件/批数据，没有简洁性

如果我们不得不这样做，我们总是会考虑使用一种更有效的技术，特别是

SSE

或

Websockets

--

苏格兰和南方能源公司

var InboxPoller;

InboxPoller = {
  poll: function() {
    return setTimeout(this.request, 5000);
  },
  request: function() {
    return $.getScript($('.inbox_wrap').data('url'), {
      after: function() {
        $('.conversation').last().data('id')
      }
    });
  }
};

$(function() {
  if ($('.inbox_wrap').length > 0) {
    return InboxPoller.poll();
  }
});

您是否考虑过使用

服务器发送事件

这是一个与Javascript轮询非常相似的方法，每几秒钟发送一次请求。不同之处在于它们的基本工作方式——收听自己的“频道”（mime类型

文本/事件流

——允许您对发送的数据进行真正的特定处理）

你可以这样称呼它：

#app/assets/javascript/application.js
var source = new EventSource("your/controller/endpoint");
source.onmessage = function(event) {
    console.log(event.data);
};

这将允许您为“事件侦听器”创建一个：

您可以使用类发送更新：

#app/controllers/your_controller.rb
类YourController

--

WebSocket

var InboxPoller;

InboxPoller = {
  poll: function() {
    return setTimeout(this.request, 5000);
  },
  request: function() {
    return $.getScript($('.inbox_wrap').data('url'), {
      after: function() {
        $('.conversation').last().data('id')
      }
    });
  }
};

$(function() {
  if ($('.inbox_wrap').length > 0) {
    return InboxPoller.poll();
  }
});

执行此操作的首选方法是使用

websockets

WebSocket比SSE或标准JS轮询效率更高，因为它们保持连接永久打开。这意味着您可以发送/接收所需的任何更新，而无需向服务器发送持续更新

WebSocket的问题在于设置过程——在自己的应用服务器上运行WebSocket连接非常困难，因此许多人不这么做

---

如果您对websocket感兴趣，您可能希望研究使用-一个有经验的第三方websocket提供商。我们经常使用这种方法-这是在应用程序中提供“实时”更新的一种非常有效的方法，而且不，我与他们没有任何关系

Javascript轮询效率极低-基本上每隔几秒钟向服务器发送请求以侦听“更新”。即使如此，在许多情况下，更新将是完整的文件/批数据，没有简洁性

如果我们不得不这样做，我们总是会考虑使用一种更有效的技术，特别是

SSE

或

Websockets

--

苏格兰和南方能源公司

var InboxPoller;

InboxPoller = {
  poll: function() {
    return setTimeout(this.request, 5000);
  },
  request: function() {
    return $.getScript($('.inbox_wrap').data('url'), {
      after: function() {
        $('.conversation').last().data('id')
      }
    });
  }
};

$(function() {
  if ($('.inbox_wrap').length > 0) {
    return InboxPoller.poll();
  }
});

您是否考虑过使用

服务器发送事件