使用带有Ajax调用的SetTimeout

Question

我试图使用setTimeout来检查表中是否存在数据:

如果数据存在则不获取数据.如果数据不存在,则使用load获取数据,然后每隔x分钟执行相同的操作.

这是我到目前为止所拥有的.出于某种原因,setTimeout当它命中If块时不起作用.

我甚至不确定这是否是最好的方法.

    var sTimeOut = setTimeout(function () {
        $.ajax({
            url: 'CheckIfDataExists/' +
                         new Date().getTime(),
            success: function (response) {
                if (response == 'True') {
                    $('.DataDiv')
                      .load('GetFreshData/' + new Date()
                          .getTime(), { "Id": $("#RowID").val() });
                }
            },
            complete: function () {
                clearTimeout(sTimeOut);
            }
        });
    }, 10000);

任何帮助将不胜感激.

更新 ...

    setTimeout(function(){checkData()}, 5000);
    function checkData(){
    $.ajax({ 
            url: 'CheckIfDataExists/' + 
                             new Date().getTime(),
            success: function (response) {
                if (response == 'True') {                     
                    $('.DataDiv')
                          .load('GetFreshData/' + new Date()
                              .getTime(), { "Id": $("#RowID").val() });
                } else {
                    $('.OutOfWindow').html('No Data Found');
                    setTimeout(function () { checkData() }, 5000);
                }
            }, 
            complete: function () { 
               // clearTimeout(sTimeOut); 
            } 
        }); 
    }

Answer 1

这样的东西应该工作,第一个片段是本地化的,所以我可以测试运行它.我已经解释了代码,下面是代码应该是什么

就像你意识到的那样(从你在帖子上的更新)setTimeout只调用你的目标函数一次,所以为了继续检查你需要再次调用它,如果你做了一个失败的检查.

在JsFiddle上看到它:http://jsfiddle.net/jQxbK/

//we store out timerIdhere
var timeOutId = 0;
//we define our function and STORE it in a var
var ajaxFn = function () {
        $.ajax({
            url: '/echo/html/',
            success: function (response) {
                if (response == 'True') {//YAYA
                    clearTimeout(timeOutId);//stop the timeout
                } else {//Fail check?
                    timeOutId = setTimeout(ajaxFn, 10000);//set the timeout again
                    console.log("call");//check if this is running
                    //you should see this on jsfiddle
                    // since the response there is just an empty string
                }
            }
        });
}
ajaxFn();//we CALL the function we stored 
//or you wanna wait 10 secs before your first call? 
//use THIS line instead
timeOutId = setTimeout(ajaxFn, 10000);

您的代码应如下所示:

var timeOutId = 0;
var ajaxFn = function () {
        $.ajax({
            url: 'CheckIfDataExists/' + new Date().getTime(),
            success: function (response) {
                if (response == 'True') {
                    $('.DataDiv').
                    load('GetFreshData/' + new Date().
                            getTime(), { "Id": $("#RowID").val() });
                     clearTimeout(timeOutId);
                } else {
                    timeOutId = setTimeout(ajaxFn, 10000);
                    console.log("call");
                }
            }
            });
}
ajaxFn();
//OR use BELOW line to wait 10 secs before first call
timeOutId = setTimeout(ajaxFn, 10000);