在传递给google.setOnLoadCallback（）的函数中使用参数; [英] Use parameter in function passed to google.setOnLoadCallback();
问题描述
我试图使用Google Visualization API来显示从MySQL服务器收集的数据。我想使用PHP获取数据，然后将其传递给javascript函数调用来创建图表。当我这样做时，我有一个问题传递给传递给google.setOnLoadCallback（）;的函数的参数。我对网络编程相当陌生，请耐心等待。工作代码（很像他们的文档）看起来像这样：
I'm trying to use Google Visualization API to display data gathered from a MySQL server. I want to get the data using PHP and then pass it into the javascript function call to create a chart. When I do this, I'm having a problem passing parameters to the function passed to google.setOnLoadCallback();. I'm fairly new to web programming, so bear with me. The working code (pretty much from their docs) looks like this:
<html>
<head>
<script type="text/javascript" src="https://www.google.com/jsapi"></script>
<script type="text/javascript">
google.load("visualization", "1", {packages:["corechart"]});
google.setOnLoadCallback(drawChart);
function drawChart() {
var data = new google.visualization.DataTable();
data.addColumn('string', 'Year');
data.addColumn('number', 'Sales');
data.addRows(4);
data.setValue(0, 0, '2004');
data.setValue(0, 1, 1000);
data.setValue(1, 0, '2005');
data.setValue(1, 1, 1170);
data.setValue(2, 0, '2006');
data.setValue(2, 1, 660);
data.setValue(3, 0, '2007');
data.setValue(3, 1, 1000);
var chart = new google.visualization.ColumnChart(document.getElementById('chart_div'));
chart.draw(data, {width: 400, height: 240, title: 'Company Performance',
hAxis: {title: 'Year', titleTextStyle: {color: 'red'}}
});
}
</script>
</head>
<body>
<div id="chart_div"></div>
</body>
</html>
我试着先看看是否可以在drawChart（）函数之外设置数据，将它作为参数传递：
I was trying to first see if I could set up the data outside of the drawChart() function and pass it as a parameter as so:
<html>
<head>
<script type="text/javascript" src="https://www.google.com/jsapi"></script>
<script type="text/javascript">
google.load("visualization", "1", {packages:["corechart"]});
var data1 = new google.visualization.DataTable();
data1.addColumn('string', 'Year');
data1.addColumn('number', 'Sales');
data1.addRows(4);
data1.setValue(0, 0, '2004');
data1.setValue(0, 1, 1000);
data1.setValue(1, 0, '2005');
data1.setValue(1, 1, 1170);
data1.setValue(2, 0, '2006');
data1.setValue(2, 1, 660);
data1.setValue(3, 0, '2007');
data1.setValue(3, 1, 1000);
google.setOnLoadCallback(drawChart(data1));
function drawChart(data) {
var chart = new google.visualization.ColumnChart(document.getElementById('chart_div'));
chart.draw(data, {width: 400, height: 240, title: 'Company Performance',
hAxis: {title: 'Year', titleTextStyle: {color: 'red'}}
});
}
</script>
</head>
<body>
<div id="chart_div"></div>
</body>
</html>
我不太清楚为什么这不起作用。使用来自PHP MySQL调用的动态收集数据来创建DataTable对象的最佳方法是什么？感谢您的时间。
I'm not too sure why this doesn't work. What would be the best way to create the DataTable object using dynamically gathered data from a PHP MySQL call? Thanks for your time.
推荐答案
以下是使其工作的步骤：
The following are the steps to make it work:
- 将google.load和google.setOnLoadCallback放置在单独的脚本标记中。
- 使用函数表达式。
以下是工作代码：
Here is the working code:
<html>
<head>
<script type="text/javascript" src="https://www.google.com/jsapi"></script>
<script type="text/javascript">
google.load("visualization", "1", {packages:["corechart"]});
google.setOnLoadCallback(function() { drawChart(data1); });
</script>
<script type="text/javascript">
var data1 = new google.visualization.DataTable();
data1.addColumn('string', 'Year');
data1.addColumn('number', 'Sales');
data1.addRows(4);
data1.setValue(0, 0, '2004');
data1.setValue(0, 1, 1000);
data1.setValue(1, 0, '2005');
data1.setValue(1, 1, 1170);
data1.setValue(2, 0, '2006');
data1.setValue(2, 1, 660);
data1.setValue(3, 0, '2007');
data1.setValue(3, 1, 1000);
function drawChart(data) {
var chart = new google.visualization.ColumnChart(document.getElementById('chart_div'));
chart.draw(data, {width: 400, height: 240, title: 'Company Performance',
hAxis: {title: 'Year', titleTextStyle: {color: 'red'}}
});
}
</script>
</head>
<body>
<div id="chart_div"></div>
</body>
</html>
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