Question

**我想在hmtl脚本中为外部javascript文件中的函数编写一个事件监听器**

/**
 * Created by ramnath on 02-03-2016.
 */
/*chart.js*/
var merry;
merry=this;
var a=10;
function starlander(){
    var name=['Year', 'Sales', 'Expenses'];
    var data1=['2004',  1000,      400];
    var data2=['2005',  1170,      460];
    var data3=['2006',  660,       1120];
    var data4=['2007',  1030,      540];
    table=[name,data1,data2,data3,data4];
    console.log("control came to me");
    //drawChart(table);
    return table;
}
function Alwayschanges(){
    this.on('input',function(msg){
        msg=msg.payload;
        return msg;
    })
}


> In this html page i want to monitor the function Alawyschanges and get msg every time there is a change in Alwayschanges funciton

<html>
<head>
    <script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
    <script type="text/javascript" src="chart.js"></script>
    <script type="text/javascript">
        google.charts.load('current', {'packages':['corechart']});
        google.charts.setOnLoadCallback(drawChart);
        function updateChart(){
            
          //event listener
            
        }
        function drawChart() {
            var data = google.visualization.arrayToDataTable(starlander());

            var options = {
                title: "you got me pal",
                curveType: 'function',
                legend: { position: 'bottom' }
            };
            var chart = new google.visualization.LineChart(document.getElementById('curve_chart'));
            chart.draw(data, options);
            updateChart();
        }
        
    </script>
</head>
<body>
<p id="demo"></p>
<div id="curve_chart" style="width: 900px; height: 500px"></div>
</body>
</html>

如何从html页面中的脚本中侦听外部js中的函数？

0 个答案: