如何使函数仅在特定函数完成后执行

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);
        }
}

此后完成drawchart(data)方法后，我只想执行以下代码但不幸的是，函数HumbleFinance.init是用空数据调用的。

请告诉我如何解决这个问题。我无法将以下代码放入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

在获取 ajax 响应并处理数据结果之前，正在对 HumbleFinance.init() 进行调用。 您需要确保在调用此init之前处理 ajax 响应。 为此，您只需将init调用移动到drawChart方法调用之后的onSuccess回调中。

<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]);
    });
});