使用jQuery自动刷新div - setTimeout或其他方法？

Question

How exactly do you make an auto-refreshing div with JavaScript (specifically, jQuery)?

I know about the setTimeout method, but is it really a good practice ? Is there a better method?

function update() {
    $.get("response.php", function(data) {
        $("#some_div").html(data);
    });
    window.setTimeout("update();", 10000);
}

Answer 1

Another modification:

function update() {
  $.get("response.php", function(data) {
    $("#some_div").html(data);
    window.setTimeout(update, 10000);
  });
}

The difference with this is that it waits 10 seconds AFTER the ajax call is one. So really the time between refreshes is 10 seconds + length of ajax call. The benefit of this is if your server takes longer than 10 seconds to respond, you don't get two (and eventually, many) simultaneous AJAX calls happening.

Also, if the server fails to respond, it won't keep trying.

I've used a similar method in the past using .ajax to handle even more complex behaviour:

function update() {
  $("#notice_div").html('Loading..'); 
  $.ajax({
    type: 'GET',
    url: 'response.php',
    timeout: 2000,
    success: function(data) {
      $("#some_div").html(data);
      $("#notice_div").html(''); 
      window.setTimeout(update, 10000);
    },
    error: function (XMLHttpRequest, textStatus, errorThrown) {
      $("#notice_div").html('Timeout contacting server..');
      window.setTimeout(update, 60000);
    }
}

This shows a loading message while loading (put an animated gif in there for typical "web 2.0" style). If the server times out (in this case takes longer than 2s) or any other kind of error happens, it shows an error, and it waits for 60 seconds before contacting the server again.

This can be especially beneficial when doing fast updates with a larger number of users, where you don't want everyone to suddenly cripple a lagging server with requests that are all just timing out anyways.

Answer 2

$(document).ready(function() {
  $.ajaxSetup({ cache: false }); // This part addresses an IE bug.  without it, IE will only load the first number and will never refresh
  setInterval(function() {
    $('#notice_div').load('response.php');
  }, 3000); // the "3000" 
});

Answer 3

你可能想尝试一个jQuery Timer插件

Answer 4

function update() {
  $("#notice_div").html('Loading..'); 
  $.ajax({
    type: 'GET',
    url: 'jbede.php',
    timeout: 2000,
    success: function(data) {
      $("#some_div").html(data);
      $("#notice_div").html(''); 
      window.setTimeout(update, 10000);
    },
    error: function (XMLHttpRequest, textStatus, errorThrown) {
      $("#notice_div").html('Timeout contacting server..');
      window.setTimeout(update, 60000);
    }
});
}
$(document).ready(function() {
    update();
});

This is Better Code