我有一个Google图表(使用
Google Visualization API,而不是
Google Charts API)在页面加载时填充.之后,用户可以从多个下拉菜单中选择选项.我希望用户能够根据他们的选择更新Google图表.
我已经创建了PHP代码,通过MysqL抓取新数据 – 用户选择了各种选项.
问题：我需要更换当前的图表吗？还是应该创建一个JavaScript函数来更新图形？
以下是我的Google Chart JavaScript代码：
google.load("visualization","1",{packages:["columnchart"]});
google.setOnLoadCallback(drawChart);
function drawChart() {
var data = new google.visualization.DataTable();
data.addColumn('string','Cluster');
data.addColumn('number','Loans');
data.addColumn('number','Lines');
/* create for loops to add as many columns as necessary */
var len = (encoded_cluster_name.length)-27; // encoded_line_volume.length;
data.addRows(len);
for(i=0; i<len; i++) {
var lines = (encoded_line_volume[i])/100000;
var loans = (encoded_loan_volume[i])/100000;
data.setValue(i,' '+encoded_cluster_name[i]+' '); /* x-axis */
data.setValue(i,1,loans); /* Y-axis category #1*/
data.setValue(i,2,lines); /* Y-axis category #2*/
}
/*********************************end of loops*****/
var chart = new google.visualization.ColumnChart(
document.getElementById('chart_div'));
chart.draw(data,{
width: 600,height: 300,is3D: true,title: 'Prospect Population',legend: 'right'
});
}
我只是更新数据而不是替换图表.并请求图表重新绘制.
您可以修改playground example进行测试.
看起来像这样：
function drawVisualization() {
// Create and populate the data table.
var data = new google.visualization.DataTable();
data.addColumn('string','Name');
data.addColumn('number','Height');
data.addRows(3);
data.setCell(0,'Tong Ning mu');
data.setCell(1,'Huang Ang fa');
data.setCell(2,'Teng nu');
data.setCell(0,174);
data.setCell(1,523);
data.setCell(2,86);
// Create and draw the visualization.
var v=new google.visualization.ColumnChart(
document.getElementById('visualization')
);
v.draw(data,null);
// Pretend update data triggered and processed
data.setCell(2,860);
v.draw(data,null);
}
