javascript - 如何使某个功能仅在某个功能完成后才执行？

Question

Event.observe(document, 'dom:loaded', function() {

    new Ajax.Request('/HumblFin/Serv', {
        method:'get',
        onSuccess: function(transport){
            var data = transport.responseText.evalJSON();
            drawChart(data);
        },
        onFailure: function(){ alert('Something went wrong...') }
    });


function drawChart(data)
{

     for (var i = 0; i < data.jobs.length; i++)  { 
         priceData.push([i, data.jobs[i].INCPU]);
         dateData.push(data.jobs[i].Dater);

        }
}

此后该drawchart(data)方法完成后，我只想执行下面的代码，但不幸的是，该函数HumbleFinance.init是用空数据调用的。

请告诉我如何解决这个问题。我不能将下面的代码放在 drawChart(data) 函数中

HumbleFinance.init('finance', priceData , dateData);
Event.observe(HumbleFinance.containers.summary, 'flotr:select', function (e) {

    var area = e.memo[0];
    xmin = Math.floor(area.x1);
    xmax = Math.ceil(area.x2);

    var date1 = dateData[xmin];
    var date2 = dateData[xmax];

    $('dateRange').update(dateData[xmin] + ' - ' + dateData[xmax]);

});
});

Answer 1

HumbleFinance.init()在您获得 ajax 响应并处理数据结果之前，您的调用就发生了。您需要确保在调用 this 之前处理您的 ajax 响应init。为此，您只需在方法调用之后将init调用移至onSuccess回调内drawChart。

<script>
Event.observe(document, 'dom:loaded', function() {

    new Ajax.Request('/HumblFin/Serv', {
        method:'get',
        onSuccess: function(transport){
            var data = transport.responseText.evalJSON();
            drawChart(data);

            //Put your HumbleFinance.init call here, 
            //after the priceData and dateData has been generated.
            HumbleFinance.init('finance', priceData , dateData);
        },
        onFailure: function(){ alert('Something went wrong...') }
    });

    Event.observe(HumbleFinance.containers.summary, 'flotr:select', function (e) {

        var area = e.memo[0];
        xmin = Math.floor(area.x1);
        xmax = Math.ceil(area.x2);

        var date1 = dateData[xmin];
        var date2 = dateData[xmax];

        $('dateRange').update(dateData[xmin] + ' - ' + dateData[xmax]);

    });
});