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ASPxDashboard.CustomDataCallback Event

Fires when a round trip to the server has been initiated by a call to the client ASPxClientDashboard.PerformDataCallback method.

Namespace: DevExpress.DashboardWeb

Assembly: DevExpress.Dashboard.v22.1.Web.WebForms.dll

Declaration

public event CustomDataCallbackEventHandler CustomDataCallback

Event Data

The CustomDataCallback event's data class is CustomDataCallbackEventArgs. The following properties provide information specific to this event:

Property Description
Parameter Gets a string that contains specific information (if any) passed from the client side. Inherited from CallbackEventArgsBase.
Result Gets or sets a string that contains specific information (if any) that needs to be passed to the client side for further processing.

Remarks

The CustomDataCallback event allows any desired server-side processing to be performed, and any resulting required information to be passed to the client for further processing (if needed).

After the CustomDataCallback event has been processed on the server side, a result can be passed back to the client via the CallbackEventArgs.Result property. To receive the result on the client, handle the ASPxClientDashboard.CustomDataCallback event.

Example

This example demonstrates how to export a dashboard displayed in ASPxDashboard on the server side using the ASPxDashboardExporter class. The following API is used to implement this capability.

View Example

using DevExpress.DashboardCommon;
using DevExpress.DashboardWeb;
using System;
using System.Collections.Generic;
using System.IO;

namespace ASPxDashboard_ServerExport
{
    public partial class Default : System.Web.UI.Page
    {
        DashboardFileStorage fileStorage = new DashboardFileStorage("App_Data/Dashboards");
        protected void Page_Load(object sender, EventArgs e)
        {
            ASPxDashboard1.AllowExportDashboard = false;         
            ASPxDashboard1.SetDashboardStorage(fileStorage);
        }

        protected void ASPxDashboard1_CustomJSProperties(object sender, DevExpress.Web.CustomJSPropertiesEventArgs e)
        {
            List<string> dashboardIDs = new List<string>();
            foreach (DashboardInfo dashboardInfo in ((IDashboardStorage)fileStorage).GetAvailableDashboardsInfo())
            {
                dashboardIDs.Add(dashboardInfo.ID);
            }
            e.Properties.Add("cpGetDashboardIDs", dashboardIDs);
        }

        protected void ASPxDashboard1_CustomDataCallback(object sender, DevExpress.Web.CustomDataCallbackEventArgs e)
        {
            using (MemoryStream stream = new MemoryStream()) {
                string selectedDashboardID = e.Parameter.Split('|')[0];
                string dashboardStateJson = e.Parameter.Split('|')[1];
                DashboardState dashboardState = new DashboardState();
                dashboardState.LoadFromJson(dashboardStateJson);

                DashboardPdfExportOptions pdfOptions = new DashboardPdfExportOptions();
                pdfOptions.ExportFilters = true;
                pdfOptions.DashboardStatePosition = DashboardStateExportPosition.Below;

                string dateTimeNow = DateTime.Now.ToString("yyyyMMddHHmmss");
                string filePath = "~/App_Data/Export/" + selectedDashboardID + "_" + dateTimeNow + ".pdf";
                ASPxDashboardExporter exporter = new ASPxDashboardExporter(ASPxDashboard1);
                exporter.ExportToPdf(selectedDashboardID, stream, new System.Drawing.Size(1920, 1080), dashboardState, pdfOptions);
                SaveFile(stream, filePath);
                e.Result = filePath;
            }
        }

        private void SaveFile(MemoryStream stream, string path)
        {
            var fileStream = File.Create(Server.MapPath(path));
            stream.WriteTo(fileStream);  
            fileStream.Close();
        }
    }
}
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="ASPxDashboard_ServerExport.Default" %>

<%@ Register Assembly="DevExpress.Dashboard.v17.1.Web, Version=17.1.17.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" 
    Namespace="DevExpress.DashboardWeb" TagPrefix="dx" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">

    <div id="selectBox" style="float: left;"></div>
    <div id="buttonContainer" style="float: left; margin-left: 150px;"></div>
    <div style="position: absolute; left: 0; right: 0; top:50px; bottom:0;">
        <dx:ASPxDashboard ID="ASPxDashboard1" runat="server" Width="100%" Height="100%" WorkingMode="Viewer"
            ClientInstanceName="webDashboard"
            ClientSideEvents-Init="function(s, e) { initializeControls(); }"
            ClientSideEvents-CustomDataCallback="function(s, e) { dashboardExportedSuccess(e); }"
            OnCustomDataCallback="ASPxDashboard1_CustomDataCallback" 
            OnCustomJSProperties="ASPxDashboard1_CustomJSProperties">
            </dx:ASPxDashboard>
    </div>
    </form>
</body>
</html>
<script type="text/javascript" src="<%= Page.ResolveClientUrl("~/Scripts/InitializeControls.js") %>"></script>
function initializeControls() {
    $("#buttonContainer").dxButton({
        text: "Export to PDF",
        onClick: function (param) {
            var selectedDashboardID = webDashboard.GetDashboardId();
            var dashboardState = webDashboard.GetDashboardState();
            var parameters = selectedDashboardID + "|" + dashboardState;
            webDashboard.PerformDataCallback(parameters, null);
        }
    });

    $("#selectBox").dxSelectBox({
        dataSource: getDashboardIDs(),
        value: getDashboardIDs()[0],
        onValueChanged: function (param) {
            webDashboard.LoadDashboard(param.value);
        }
    });
}

function getDashboardIDs() {
    return webDashboard.cpGetDashboardIDs;
};

function dashboardExportedSuccess(args) {
    DevExpress.ui.notify('A dashboard was exported to ' + args.result, 'success', 5000);
};
See Also