javascript - 在 JavaScript 中为我的 Rails 应用程序显示弹出消息

Question

问题是在我的 Rails 应用程序中，我的用户 Controller 中有一个方法可以自动填充。这会在新用户注册时填写一个表格。当他们填写我的 emp_id 文本框时，它会查看我的员工表，如果 ID 与他们输入的 emp_id 匹配，我将从该表中提取此数据。自动填充 emp_first_name 和 emp_last_name。当数据返回有数据时，我能够弹出一条消息，但是，我一直在思考如何在该特定 emp_id 不存在数据时显示消息...

这是我的 Controller

class UserController < ApplicationController

  def populate_form

    @visual = Visual.find_by_id(params[:emp_id])


    if @visual.nil?

      respond_to do |format|
        format.json { render json: @user, status: :unprocessable_entity, flash[:error] => "Error No ID found." }   
        #This didn't work no message displays..
      end

    else


      @emp_first_name = @visual.first_name

      @emp_last_name = @visual.last_name

        render :json => {

           :emp_first_name => @emp_first_name,
           :emp_last_name => @emp_last_name

        }
     end
   end

这是我的观点..

<div class='row form-group'>
  <div class='col-xs-8 col-xs-offset-2 col-sm-6 col-sm-offset-3 col-md-4 col-md-offset-4 col-lg-2 col-lg-offset-5 text-right'>
    <%= f.text_field :emp_id, tabindex: 1, id: 'emp_id', autofocus: true, placeholder: t( 'login_label' ), class: 'form-control' %>
  </div>
</div>

<div class='row form-group'>
  <div class='col-xs-8 col-xs-offset-2 col-sm-6 col-sm-offset-3 col-md-4 col-md-offset-4 col-lg-2 col-lg-offset-5 text-right'>
    <%= f.text_field :emp_first_name, tabindex: 1, id: 'emp_first_name', autofocus: true, placeholder: t( 'emp_first' ), class: 'form-control' %>
  </div>
</div>

<div class='row form-group'>
  <div class='col-xs-8 col-xs-offset-2 col-sm-6 col-sm-offset-3 col-md-4 col-md-offset-4 col-lg-2 col-lg-offset-5 text-right'>
    <%= f.text_field :emp_last_name, tabindex: 1, id: 'emp_last_name', autofocus: true, placeholder: t( 'emp_last' ), class: 'form-control' %>
  </div>

这是我的 app.js

 $(document).ready(function(){
   $('#emp_id').change(function() {
     var url = "/user/populate_form?emp_id="+$(this).val();
     $.getJSON(url, function(data) {
       if(!(data.emp_first_name === undefined))
         $('#emp_first_name').val(data.emp_first_name);
       if(!(data.emp_last_name === undefined))
         $('#emp_last_name').val(data.emp_last_name);
       if('#emp_first_name' === null) {
         alert('Fail employee ID wasn't found please try again with a valid employee ID.');
       } else  {
         alert('Your employee ID has been found please fill in the email and password fields then click submit to register.');
       }
     });}
   );
 });

Answer 1

.您可以使用不同的ajax callbacks检查 json 响应是否失败，然后显示错误消息。您可以使用空白占位符来显示警报消息。例如:-

在 Controller 中使用它来显示 json 错误

class UserController < ApplicationController

  def populate_form

    @visual = Visual.find_by_id(params[:emp_id])


    if @visual.present?
        respond_to do |format|
            @emp_first_name = @visual.first_name
            @emp_last_name = @visual.last_name
             render :json => {

                 :emp_first_name => @emp_first_name,
                 :emp_last_name => @emp_last_name
                              }
    else       
            format.js { render :json => "id not present", :status => 400 }
            format.html { render :json => "id not present" , :status => 400 }

         end    
     end
   end

查看文件，带占位符

<div id="show_alert" style="display:none;"></div>

js代码，显示警报

 $('#emp_id').change(function() {
       var url = "/user/populate_form?emp_id="+$(this).val();
       $.getJSON(url, function(data) {
         if(!(data.emp_first_name === undefined))
         $('#emp_first_name').val(data.emp_first_name);
         if(!(data.emp_last_name === undefined))
         $('#emp_last_name').val(data.emp_last_name);
          }).done(function (response) {
                  if (response.success == 'success') {               
                      //alert('success');    
                        $("#show_alert").html("<span class='text-success marginl10' ><b>Your employee ID has been found please fill in the email and password fields then click submit to register..</b></span>")
                  } else {
                      //alert('fail');
                      $("#show_alert").html("<span class='text-danger     marginl10' ><b>Fail employee ID wasn't found please try again with a valid employee ID.</b></span>").show();
                  }
       });
     }
   );
 });