Detailed explanation of the steps to implement loading progress bar with Ajax

This time I will bring you a detailed explanation of the steps to implement Ajax loading progress bar . What are the precautions for Ajax implementation of loading progress bar? Here is a practical case, let’s take a look. one time.

ajax beforeSend:

Let’s talk about this beforeSend first. It can be executed before the request is sent. For example, it can determine the user. Are you logged in? If not, stop the request and prompt.

  $.ajax({
    url : 'my_action',
    dataType: 'script',
    beforeSend : function(xhr, opts){
      if(1 == 1) //just an example
      {
        xhr.abort(); // 停止请求
      }
    },
    complete: function(){
      console.log('DONE');
    }
  });

$.ajax has a parameter complete: function(){} is executed after the request is completed. It can be used to display the progress bar with beforeSend

For example:

   $.ajax({
        url : 'my_action',
        dataType: 'script',
        beforeSend : function(){
          // 设置 进度条到20%慢慢变到50%
        },
        complete: function(){
          // 设置 进度条到80%
        }
        success：function(){
          // 渲染页面
          // 进度到100%
        }
      });

This is just the progress bar seen on the surface, showing the approximate progress, not the real loading progress.

I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!

Recommended reading:

How to operate Ajax to post request to jump page

Ajax detailed steps for uploading files and parameters

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