I'm trying to use a google visualisation, the column chart, inside an asp.net AJAX Toolkit Tab Control, but I'm having small (literally) problems.
If I add the visualisation to the tab that's displayed by default when the page loads, the bar chart displays correctly, however, if I add the same control to another tab and reload the page, when I click on the other tab, the control is displayed, but its tiny and unusable.
Here's some code for a test.aspx page that illustrates the problem:
<%@ Page Language="vb" AutoEventWireup="false" CodeBehind="Default.aspx.vb" Inherits="TestProject._Default" %>
<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="cc1" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title></title>
<script type="text/javascript" src="http://www.google.com/jsapi"></script>
<script type="text/javascript">
google.load('visualization', '1', { packages: ['columnchart'] });
</script>
<script type="text/javascript">
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, 0, 'Tong Ning mu');
data.setCell(1, 0, 'Huang Ang fa');
data.setCell(2, 0, 'Teng nu');
data.setCell(0, 1, 174);
data.setCell(1, 1, 523);
data.setCell(2, 1, 86);
// Create and draw the visualizations.
new google.visualization.ColumnChart(document.getElementById('visualization1')).
draw(data, null);
new google.visualization.ColumnChart(document.getElementById('visualization2')).
draw(data, null);
}
google.setOnLoadCallback(drawVisualization);
</script>
</head>
<body>
<form id="form1" runat="server">
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<div>
<cc1:TabContainer ID="TabContainer1" runat="server">
<cc1:TabPanel runat="server" HeaderText="TabPanel1" ID="TabPanel1">
<ContentTemplate>
<div id="visualization1" style="width: 300px; height: 300px;">
</div>
</ContentTemplate>
</cc1:TabPanel>
<cc1:TabPanel runat="server" HeaderText="TabPanel1" ID="TabPanel2">
<ContentTemplate>
<div id="visualization2" style="width: 300px; height: 300px;">
</div>
</ContentTemplate>
</cc1:TabPanel>
</cc1:TabContainer>
</div>
</form>
</body>
</html>
Ok, I didn't get a single response to this post so here is how I worked around the problem, hope it helps someone.
I never actually got the the root of this problem but I found that if I delayed the loading of the Visualisations till the tab that contains it is clicked then the problem goes away.
In the TabControl I call a JavaScript function to load the tabs visualisation when clicked:
<cc1:TabContainer ID="TabContainer1" runat="server" OnClientActiveTabChanged="tabChanged">
<cc1:TabPanel runat="server" HeaderText="TabPanel1" ID="TabPanel1">
<ContentTemplate>
<div id="visualization1" style="width: 300px; height: 300px;"></div>
</ContentTemplate>
</cc1:TabPanel>
<cc1:TabPanel runat="server" HeaderText="TabPanel1" ID="TabPanel2">
<ContentTemplate>
<div id="visualization2" style="width: 300px; height: 300px;"></div>
</ContentTemplate>
</cc1:TabPanel>
</cc1:TabContainer>
The JavaScript function
function tabChanged(sender, args) {
var ActiveTab = sender.get_activeTabIndex();
if (sender.get_activeTabIndex() == 0) {
if (tab0Loaded != true) {
//load the visualisation
new google.visualization.ColumnChart(document.getElementById('visualization2')).draw(data, null);
tab0Loaded = true
}
}
if (sender.get_activeTabIndex() == 1) {
if (tab1Loaded != true) {
//load the visualisation
new google.visualization.ColumnChart(document.getElementById('visualization2')).draw(data, null);
tab1Loaded = true
}
}
}
During postback the active tab could change, to cope with this I have a JavaScript function that executes when the page loads, if the current active tab is one containing a visualisation then I load it.