Question

在下面的代码中调用api execute_wc，后者又调用递归函数poll_results并仅在有状态时返回！= 1.现在函数poll_results是称它是异步的，因此if else中的submit_stat条件不会被执行。如何处理这种情况

function submit_stat(){
    var poll_status = '';
    $.post("/reports/execute_wc/", snddata,
    function callbackHandler(data, textstatus)
    {
        console.log('got response');
        if (data.status == 0)
        {
            poll_status  = poll_results();
            if (poll_status == 1){

            }
            else if(poll_status == 0)
            {
                alert('Error while processing data.Please check input files');
            }
        }
        else if (data.status == 1)
        {
                alert('Error while processing data');
        }
     },
     "json"
     );
}

function poll_results(){
  $.post('/reports/poll_wcstatus/', function(data) {
    if(data.wce_status == 1){
        return setTimeout(poll_results,5000);
    }
    else if (data.wce_status != 1 || data.wce_status != 3)  
    {
        alert('return 1');
        return 1;
    }
    else 
    {
        alert('return 0');
        return 0;
    }
   });
 }

编辑1：

function poll_results(callback){
  var callback='';
  $.post('/reports/poll_wcstatus/', function(data) {
    //alert(data);  // process results here
    console.log(data);
    console.log(data.wce_status);
    if(data.wce_status == 1){
        return setTimeout(poll_results,5000);
    }
    else if (data.wce_status != 1 || data.wce_status != 3){
        alert('return 1');
        //return 1;
        callback(1);
    }
    else //3 is fatal error shoul
    {
        alert('return 0');
        callback(0);
        //return 0;
    }
});
}



 $.post("/reports/execute_wc/", snddata,
    function callbackHandler(data, textstatus)
    {
        console.log('got response');
        if (data.status == 0)
        {
            alert('starting script');
            //poll_status  = poll_results();
            poll_results(function(poll_status){
                if (poll_status == 1){
                    alert('Content extratcted.Please download the results file');
                    $('#loading').hide();
                    $('#downloadfile').show();
                    $('#downloadfile').html('').append('<a href="'+ data.url +'">Download output</a>');
                }
                else if(poll_status == 0)
                {
                    $('#loading').hide();
                    alert('Error while processing data.Please check input files');
                }
            });
        }
        else if (data.status == 1)
        {
            $('#loading').hide();
            alert('Error while processing data');
        }
     },
     "json"
     );

Answer 1

您可以使用回拨功能。以下示例

function submit_stat(){
    var poll_status = '';
    $.post("/reports/execute_wc/", snddata,
    function callbackHandler(data, textstatus)
    {
        console.log('got response');
        if (data.status == 0)
        {
           poll_results(function(poll_status){  //pass a function definition as a parameter to your another function, this is called callback function
             if (poll_status == 1){

             }
             else if(poll_status == 0)
             {
                alert('Error while processing data.Please check input files');
             }
           });

        }
        else if (data.status == 1)
        {
                alert('Error while processing data');
        }
     },
     "json"
     );
}

function poll_results(callback){   //here callback variable holds a function within it
  $.post('/reports/poll_wcestatus/', function(data) {
    if(data.wce_status == 1){
        return setTimeout(poll_results,5000);
    }
    else if (data.wce_status != 1 || data.wce_status != 3)  
    {
        alert('return 1');
        callback(1);  //execute the callback function
    }
    else 
    {
        alert('return 0');
        callback(0);  //execute the callback function
    } 
   });
 }

Answer 2

为了异步接收数据，您需要使用回调。向poll_results添加一个函数，并在异步调用完成时传递数据。

function submit_stat(){
    var poll_status = '';
    $.post("/reports/execute_wc/", snddata,
    function callbackHandler(data, textstatus)
    {
        console.log('got response');
        if (data.status == 0)
        {
            poll_results(function(poll_status)
            {
                if (poll_status == 1){

                }
                else if(poll_status == 0)
                {
                    alert('Error while processing data.Please check input files');
                }
            });
        }
        else if (data.status == 1)
        {
                alert('Error while processing data');
        }
     },
     "json"
     );
}

function poll_results(callback){
  $.post('/reports/poll_wcstatus/', function(data) {
    if(data.wce_status == 1){
        return setTimeout(poll_results,5000);
    }
    else if (data.wce_status != 1 || data.wce_status != 3)  
    {
        callback(1);
    }
    else 
    {
        callback(0);
    }
   });
 }

jquery进行同步调用和执行

2 个答案: