FusionCharts v3 Documentation

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Using FusionCharts with ASP.NET 2.0 (C#)>> ASP.NET.AJAX Update Panel

FusionCharts can effectively be used in ASP.NET AJAX Update Panel to plot dynamic data-driven charts. In this example, we'll show a few basic examples to help you get started.

We'll cover the following examples here:

We'll use FusionCharts in an Update Panel taking data from a database.
We'll then use 2 FusionCharts, one of which affects the other chart in an Update panel.

Let's quickly see each of them.

Before you go further with this page, we recommend you to please see the previous sections "Basic Examples" and other subsequent pages as we start off from concepts explained in that page.

All code discussed here is present in Download Package > Code > CS > UpdatePanel folder.

To use Update Panel, you need to have ASP.NET AJAX Extension installed in your machine. You can download it from http://www.asp.net/ajax/downloads.
You need to rename the given web.config.ajax to web.config to incorporate the ASP.NET.AJAX extension.

We will create 3 UpdatePanels:

First on top with RadioButtonList control to select Factory Name (id - FactorySelector)
Left - with a GridView control showing selected Factory's output data -(id - GridUP)
Right - with a Column2D chart (using FusionCharts) to show factory output data (id - FusionChartsUP)

The design view will look like this :

Let's look at the UpdatePanel code for the FactorySelector: (Sample1.aspx)

<asp:UpdatePanel ID="FactorySelector" runat="server">

   <ContentTemplate>

     <asp:RadioButtonList ID="RadioButtonList1" runat="server" AutoPostBack="True" Height="40px"

OnSelectedIndexChanged="RadioButtonList1_SelectedIndexChanged" Width="400px"

            RepeatDirection="Horizontal" Style="font-weight: bold; font-size: 14px; font-family: Verdana"

ForeColor="#404040">

      </asp:RadioButtonList>

    </ContentTemplate>

</asp:UpdatePanel>

Here, we set a code behind function to be called when selection changes. Since AutoPostBack is set to true it will invoke AJAX call.

The UpdatePanel code that will contain the chart is simpler.

<asp:UpdatePanel ID="FusionChartsUP" runat="server">

   <ContentTemplate>

        <asp:Panel ID="Panel1" runat="server" Height="350px" Width="440px">

        </asp:Panel>

   </ContentTemplate>

</asp:UpdatePanel>

Here we place a Panel control where the chart will be loaded.

Now let's find out what happens in the code-behind (Sample1.aspx.cs) function RadioButtonList1_SelectedIndexChanged() when a Factory is selected :

 protected void RadioButtonList1_SelectedIndexChanged(object sender, EventArgs e)

{

    //Update FusionCharts and gridview with as per selected factory

    updateChart();

}

It calls UpdateChart() function. Let's trace it:

private void updateChart()
{
//Get factory details depending on FactoryID from selected Radio Button
string strSQL = "select DatePro, Quantity from Factory_Output where FactoryId=" + RadioButtonList1.SelectedValue.ToString() + " order by DatePro";

   //Create data reader to bind data with GridView
   DbConn rs = new DbConn(strSQL);
   //Fillup gridview with data from datareader
   GridView1.DataSource = rs.ReadData;
   // binding the data
   GridView1.DataBind();

//Create database connection to get data for chart
DbConn oRs = new DbConn(strSQL);

//Create FusionCharts XML
StringBuilder strXML = new StringBuilder();

//Create chart element
strXML.AppendFormat("<chart caption='Factory {0}' showborder='0' bgcolor='FFFFFF' bgalpha='100' subcaption='Daily Production' xAxisName='Day' yAxisName='Units' rotateLabels='1' placeValuesInside='1' rotateValues='1' >", RadioButtonList1.SelectedValue.ToString());

   //Iterate through database
   while (oRs.ReadData.Read())
   {
      //Create set element
      //Also set date into d/M format
      strXML.AppendFormat("<set label='{0}' value='{1}' />", Convert.ToDateTime(oRs.ReadData["DatePro"]).ToString("d/M"), oRs.ReadData["Quantity"].ToString());
   }

//Close chart element
strXML.Append("</chart>");

   //outPut will store the HTML of the chart rendered as string
   string outPut = "";
   if (IsPostBack)
   {
      //when a ajax call is made we use RenderChartHTML method
      outPut = FusionCharts.RenderChartHTML("../FusionCharts/Column2D.swf", "", strXML.ToString(), "chart1", "445", "350", false, false);
   }
   else
   {
      //When the page is loaded for the first time, we call RenderChart() method to avoid IE's 'Click here to Activate...' message
      outPut = FusionCharts.RenderChart("../FusionCharts/Column2D.swf", "", strXML.ToString(), "chart1", "445", "350", false, false);
   }

//Clear Panel control which will contain the chart
Panel1.Controls.Clear();

//Add Literal control to Panel which adds the chart from outPut string
Panel1.Controls.Add(new LiteralControl(outPut));

//Close Data Reader
oRs.ReadData.Close();
}

In the above code we do the following :

Open database connection to get data for the selected factory
Update the GridView control with data from database
Create the chart XML
Use InfoSoftGlobal.FusionCharts.RenderChartHTML method to generate HTML for the chart to be displayed
Update the Panel control in the FusionChartsUP UpdatePanel with this HTML for the chart

Note that we also used InfoSoftGlobal.FusionCharts.RenderChart() method when isPostBack is false. We do this for a specific reason to deal with the Internet Explorer's 'Click Here to Activate Control' message when a page loads for the first time, i.e., when no post back is done.

Thus, the chart gets updated in UpdatePanel, using AJAX, each time a factory is selected from the Radio buttons list. Here goes a screenshot of one instance :

We now modify the sample above to insert two charts. One on the left, a pie chart with summary data, showing total production of each Factory in each slice. On clicking a slice, i.e., selecting a Factory, another chart will show up in an UpdatePanel. This chart, a Column2D chart, like the previous example will show the details of the selected Factory.

Let's see how the design is modified :(Sample2.aspx)

Here, we put only one UpdatePanel i.e., FusionChartsUP that will load up the chart. The HTML code for this remains the same as the previous example. The left part will contain the Pie chart that will load up once, when the page is loaded first. But we have an added Javascript to add in this page :

<script language="javascript" type="text/javascript">

//Call Ajax PostBack Function

function updateChart(factoryId){

//Call drillDown C# function by Ajax

         //we pass the name of the function ('drillDown') to call 

//and the parameter (i.e., factoryId) to be passed to it

         //both separated by a delimiter(here we use $, you can use anything)

         __doPostBack("Panel1","drillDown$" + factoryId);

}

</script>

This function is actually invoked when a pie slice is clicked. The factory id is passed to the function. This function used the ASP.NET.AJAX 's function __doPostBack(). This function takes 2 parameters. The first one is name of the control where post-back updates will be reflected. Through the second parameter, we pass the name of the code-behind function to be called along with the parameter. This parameter is passed to the code-behind script as request variable - __EVENTARGUMENT.

To know more on how to evoke JavaScript functions form a chart please refer to section Guide for Web Developers >> Drill Down Charts

Let's now see how the request is treated in the code-behind file Sample2.aspx.cs.

protected void Page_Load(object sender, EventArgs e)
{
   //This will execute first time the page loads and not on ajax post back calls
   if (!IsPostBack)
   {
      // Show a blank Column2D Chart at first
      showColumnChart();
   }
   else
   {
      // Handle Ajax PostBack Call
      // store Asp.Net Ajax special HTTP request
      // __EVENTARGUMENT holds value passed by JS function -__doPostBack
      //The value can be like "drillDown$1"
      //We take $ as delimiter so we get drillDown as the function to call
      //and 1 as the factory id. It can vary depending on the pie slice clicked.

      String sEventArguments = Request["__EVENTARGUMENT"];
      if (sEventArguments != null)
      {
         //extract arguments passed to the HTTP Request
         Int32 iDelimiter = sEventArguments.IndexOf('$');
         String sArgument = sEventArguments.Substring(iDelimiter + 1);
         // extract the name of the post back function
         if (sEventArguments.StartsWith("drillDown"))
         {
            // call the post back function passing the argument(s)
            drillDown(sArgument);
         }
      }
   }

}

The above code is executed whenever a page is loaded be is at first or through AJAX call. It does the following :

It loads a blank Column2D chart on first load calling function showColumnChart()
On post-back calls it parses the __EVENTARGUMENT request and extract the name of the function to be called and argument to be passed to the function. Here the argument will be the Factory Id.
Accordingly the function name that the request gives is DrillDown and is called.
DrillDown() function is same as the updateChart() function of the previous example, which creates chart XML as per the selected Factory and sets the panel with the chart HTML created using InfoSoftGlobal.FusionCharts.RenderChartHTML function.

The final output will look like this :