javascript - 如何使用 AJAX 将数据从 ruby​​ Controller 发送到应用程序 javascript？

Question

我的 application.js 中有一个 AJAX 调用，它将 3 条数据发送到我的 events_controller#check 操作:

//application.js
    $(document).on('click', "#check-button", function(){

        ...

        $.ajax({
                url: '/events/check',
                data: {checkList: checkList , selected_date: selectedDate , length: length },

            }
        );

    });

我的检查操作:

#events_controller.rb
def check
    checkList = params[:checkList]
    selected_date = params[:selected_date]
    length = params[:length]

    busy_array = Array.new #this needs to be rendered in the view

    ...
    busy_array.push(user.id) #busy_array is a list of user ids from database


  end


#routes.rb
resources :events do
    get :check, on: :collection
  end

View :

<button id="check-button" type="button">Check</button>

          <div class = "col-md-6" id="unavailable">
            <h2>Unavailable on this day:</h2>
            <ol id="unavailable-list">
              <li>THIS LIST SHOULD BE POPULATED BY BUSY_ARRAY</li>
            </ol>
      </div>

现在我需要将数据从 events_controller#check 发送回 View ，但我不知道如何发送 busy_array 以在 events 中呈现\new.html.erb

感谢您的帮助，我是 ruby​​/JS 初学者

Answer 1

busy_array = Array.new #this needs to be rendered in the view

如果必须在 View 中可用，则需要定义一个 @instance 变量:

def check
    checkList = params[:checkList]
    selected_date = params[:selected_date]
    length = params[:length]

    @busy_array = Array.new
    ...
    @busy_array.push(user.id) #busy_array is a list of user ids from database
end

每次调用 controller#action 时，action 内的数据/变量都会受到 local scope 的约束。 .

在 View 中输出数据需要变量在类的整个实例中可用(不仅仅是操作/函数)。因此@busy_array。

<小时/>

修复

#app/views/events/....
<%= button_to "Check", events_check_path %>

<div class = "col-md-6" id="unavailable">
  <h2>Unavailable on this day:</h2>
  <ol id="unavailable-list">&nbsp;</ol>
</div>

#app/assets/javascripts/application.js
$(document).on('click', "#check-button", function(e){
  ...
  $.get('/events/check', {checkList: checkList , selected_date: selectedDate , length: length});
});

#app/controllers/events_controller.rb
class EventsController < ApplicationController
  def check
    @busy_array = User.joins(:event).where(event: { ... }).pluck(:id) #-> return user ids where event.x = y
    respond_to do |format|
      format.js     #-> invokes app/views/events/check.js.erb
      format.html   #-> invoked when HTML request sent
    end
  end
end

#app/views/events/check.js.erb
<% @busy_array.each do |id| %>
   $("ol#unavailable-list").append("<%=j id %>")
<% end %>

<小时/>

I don't know how to send busy_array to be rendered in events\new.html.erb

如果该变量是 @instance var，则该变量将在 new 中可用:

#app/views/events/new.html.erb
<%= @busy_array %>

view 是 EventsController 类实例的一部分，但在 check 方法的范围之外。当您向 Rails 发送请求时，它会使用 Controller 的实例来编译一组 HTML 以返回到您的浏览器。

例如，您可以将 EventsController 流程总结如下:

Request > Routing > EventsController.new(request).action > Returned HTML

如果您手动设置 EventsController.new(request)，您将得到以下结果:

@event = EventsController.new request

@event.check    #-> "busy_array" locally scoped to this function
@event.response #-> outputs view code.... @busy_array needs to be instance var

如果您阅读MVC，您会更好地理解: