所有,

我正在使用以下HTML / Javascript代码:

<!doctype html>
<html>
<head>
    <script type="text/javascript" src="//ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
    <!-- google fonts from CDN -->
    <link href='http://fonts.googleapis.com/css?family=Open+Sans:400,300,600' rel='stylesheet' type='text/css'>
    <!-- highcharts -->
    <script src="http://code.highcharts.com/highcharts.js"></script>

    <style>
        html, body {
            width: 95%;
            margin: auto;
            font-family: 'Open Sans',sans-serif;
        }
        #chart_container {
            width:100%;
            height:500px;
        }
    </style>
</head>
<body>
    <h1>Live Data</h1>
    <div id="chart_container">

    </div>
</body>
<script type="text/javascript">
    $(document).ready(function() {
        chart = new Highcharts.Chart({
            chart: {
                renderTo: 'chart_container',
                defaultSeriesType: 'line',
                events: {
                    load: getBirds
                }
            },
            title: {
                text: 'DRHW Live Data Stream'
            },
            xAxis: {
                type: 'datetime',
                tickPixelInterval: 150,
                maxZoom: 20 * 1000
            },
            yAxis: {
                title: {
                    text: 'Count Observed'
                }
            },
            series: [
            ],
            legend: {
                layout: 'horiztonal',
                align: 'center'
            }
        });
        function getBirds() {
            var now = new Date();
            var et = now.getTime() / 1000; //PHP TS
            var st = et - 10; //30 seconds prior in PHP
            console.log(chart);
            if (chart.series.length > 0) {
                var series = chart.series[0];
                var length = series.length + 1;
                var shift = series.data.length > 20;
            }
            $.getJSON("https://path/to/json&callback=?", function(result) {
                var data = result.data;if (data.length == 0) {
                    return;
                } else {
                    additions = new Array();
                    for (i=0;i<data.length;i++) {
                        if (data[i].qstype != "1") {
                            species = data[i].answers[0]['answer'];
                            scode = species.substring(0,species.search(" - ")).trim()
                            count = (data[i].answers[1]['answer'] * 1);
                            newdata = new Object();
                            newdata['name'] = species;
                            newdata['count'] = count;
                            additions.push(newdata);
                        }
                    }
                    //now, for each addition, you need to loop through the existing data structures, and see if the thing exists.  if it does, add the data; if not, add the thing, then add the data.
                    var existingdata = chart.series;
                    for (i=0;i<additions.length;i++) {
                        isnewpoint = true;
                        for (j=0;j<existingdata.length;j++) {
                            if (existingdata[j].name == additions[i].name) {
                                isnewpoint = false
                                count = additions[i].count;
                                point = [now.getTime(),count];
                                chart.series[j].addPoint(point, true, shift);
                                shift = false; //this way, only one shift occurs - the first time through adding a new point to an existing data set. this will control against future shifting, either from other datapoints having new points added,
                            }
                        }
                        if (isnewpoint) {
                            newseries = new Object();
                            count = additions[i].count;
                            newseries['name'] = additions[i].name;
                            for (j=0;j<length;j++) {
                                newseries['data'].push(0);
                            }
                            newseries['data'].push(count);
                            chart.series.push(newseries);
                        }
                    }
                    //we have now looped through and added a new data point to all species where new data was created in this pull.  We still need to add a new point to those that were not affected.
                    existingdata = chart.series;
                    for (i=0;i<existingdata.length;i++) {
                        getname = existingdata[i].name;
                        getlength = existingdata[i].data.length;
                        if (getlength<length) { //which we established earlier as one MORE than existed previously, prior to the addition
                            point = [now.getTime(),0]
                            chart.series[i].addPoint(point, true, shift);
                        }
                    }
                }
                setTimeout(getBirds,10000);
            });
        }
    });
</script>

</html>

我遇到的问题非常简单(但是让我发疯了!),并且早在js块中。尽管我将变量'chart'定义为新的Highcharts图表,并且将'getBirds'设置为要在加载后加载的函数,但console.log行告诉我该图表未定义,下面的行它将引发错误(Uncaught TypeError: Cannot read property 'series' of undefined)。

我检查了以下内容:
  • Highcharts引用(http://www.highcharts.com/docs/working-with-data/preprocessing-live-data),它建议一个类似于我的设置;
  • 我尝试在自己的行上定义chart变量(当然,该变量定义了console.log的图表,但未定义下一行所需的chart.series);
  • 我已经研究了stackoverflow和其他有关可变范围的文档,但我认为我根据自己的研究正确地对其进行了处理。
  • 我尝试过反转顺序-将getBirds()函数放在chart定义上方。

  • 我很茫然。提供的任何帮助将不胜感激;提前致谢!

    最佳答案

    原因很可能是您无法在变量声明阶段引用它。我猜是在声明加载函数时调用了它。幸运的是,您可以在函数声明期间引用该对象。尝试下面的代码块。

    function getBirds(e) {
        var now = new Date(),
            et = now.getTime() / 1000, //PHP TS
            st = et - 10, //30 seconds prior in PHP
            chart = this;
        if (chart.series.length > 0) {
    

    ...在其中的var块中声明chart变量。

    09-17 14:51
    查看更多