How to use jquery scheduled refresh

jQuery is a commonly used JavaScript library that can help developers more easily operate HTML documents, handle events, create animations, implement asynchronous requests, etc., while scheduled refresh is a function that allows web pages to automatically refresh. Some specific Required under certain circumstances. This article will introduce how to use scheduled refresh in jQuery.

1. Use the setInterval function

setInterval is a common timer function in JavaScript. It can repeatedly execute a specified code block at intervals. The selected time interval is determined by the second part of the function. parameter settings. When using jQuery for scheduled refresh, we can use the setInterval function to achieve this purpose.

The following is a simple example that obtains data from the server every 1 second:

setInterval(function(){
   $.get("data.php", function(result){
      // 在此处处理返回结果
   });
}, 1000);

This code defines a function that runs every 1 second, It uses jQuery's $.get function to obtain the return result of data.php and transfers the result to the callback function. Within the callback function, we can process the results, such as updating HTML elements or creating animations, etc.

2. Use the setTimeout function

The setTimeout function is very similar to the setInterval function, but it will only execute the specified code block once after the specified time. If we need to simulate the effect of scheduled refresh, we can use the setTimeout function to implement a timer that executes in a loop.

The following is a simple example:

function refreshData(){
   $.get("data.php", function(result){
      // 在此处处理返回结果
      setTimeout(refreshData, 1000); // 每隔1秒钟再次刷新
   });
}

$(document).ready(function(){
   refreshData(); // 初始运行
});

This code defines a function named refreshData, which will execute itself repeatedly after obtaining the data. When our page is loaded, we call the refreshData function, which will start running and automatically refresh the data every 1 second.

3. Use jQuery’s load function

jQuery’s load function can help us update HTML elements asynchronously, such as an embedded div element. Unlike the get and post functions, the load function can directly load the specified URL. If the specified URL does not have any parameters, it is equivalent to reloading the URL every time.

The following is an example:

$(document).ready(function(){
   setInterval(function(){
      $("#myDiv").load("data.php"); // 每隔5秒钟重载数据
   }, 5000);
});

This code uses jQuery's load function, which obtains data from the server and inserts the returned HTML data into the myDiv element. In this example, we use the setInterval function to automatically refresh the data every 5 seconds.

4. Summary

When using jQuery for scheduled refresh, we can choose to use the setInterval function, setTimeout function or jQuery's load function. Scheduled refresh can help us achieve the effect of automatically updating data or dynamically updating pages, but it needs to be used with caution because it will occupy server resources and slow down the loading speed of the website. If you need to use scheduled refresh, please optimize it to avoid unnecessary burden on users.

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