Exporting a report to PDF programmatically

Environment

Product

Progress® Telerik® Reporting

Description

This article explains how to export a report to PDF without the need to go through a report viewer.

Solution

For ASP.NET Framework

You can use the following code snippet to programmatically export the report into PDF format from a Web Site or Web Application project:

void ExportToPDF(Telerik.Reporting.Report reportToExport)
{
    ReportProcessor reportProcessor = new ReportProcessor();
    Telerik.Reporting.InstanceReportSource instanceReportSource = new Telerik.Reporting.InstanceReportSource();
    instanceReportSource.ReportDocument = reportToExport;
    RenderingResult result = reportProcessor.RenderReport("PDF", instanceReportSource, null);

    string fileName = result.DocumentName + "." + result.Extension;

    Response.Clear();
    Response.ContentType = result.MimeType;
    Response.Cache.SetCacheability(HttpCacheability.Private);
    Response.Expires = -1;
    Response.Buffer = true;

    Response.AddHeader("Content-Disposition",
                    string.Format("{0};FileName=\"{1}\"",
                                    "attachment",
                                    fileName));

    Response.BinaryWrite(result.DocumentBytes);
    Response.End();
}

Sub ExportToPDF(ByVal reportToExport As Telerik.Reporting.Report)

    Dim reportProcessor As New ReportProcessor()
    Dim instanceReportSource As New Telerik.Reporting.InstanceReportSource()
    instanceReportSource.ReportDocument = reportToExport
    Dim result As RenderingResult = reportProcessor.RenderReport("PDF", instanceReportSource, Nothing)

    Dim fileName As String = result.DocumentName + "." + result.Extension 
    Response.Clear()
    Response.ContentType = result.MimeType
    Response.Cache.SetCacheability(HttpCacheability.Private)
    Response.Expires = -1
    Response.Buffer = True
    Response.AddHeader("Content-Disposition", String.Format("{0};FileName=""{1}""", "attachment", fileName))   
    Response.BinaryWrite(result.DocumentBytes)
    Response.End()
End Sub

For ASP.NET Core

In ASP.NET Core, the Response object does not expose a BinaryWrite method. For that reason, the approach will need to change a little. We can instead convert the document bytes, of the result object returned by the RenderReport method, to a Base64 string and we may then return it.

[HttpGet]
public IActionResult GenerateReportPDF(string reportName)
{
    var reportProcessor = new Telerik.Reporting.Processing.ReportProcessor();

    // set any deviceInfo settings if necessary
    var deviceInfo = new System.Collections.Hashtable();

    var reportSource = new Telerik.Reporting.UriReportSource();

    reportSource.Uri = @"C:\Program Files (x86)\Progress\Telerik Reporting Version\Report Designer\Examples\Dashboard.trdp";

    Telerik.Reporting.Processing.RenderingResult result = reportProcessor.RenderReport("PDF", reportSource, deviceInfo);

    var b64 = Convert.ToBase64String(result.DocumentBytes);
    return new ContentResult() { Content = b64 };
}

Then, on the client side, we need to convert that Base64 string back to array. The following function may be used for the task:

function base64ToArrayBuffer(data) {
        var binaryString = window.atob(data);
        var binaryLen = binaryString.length;
        var bytes = new Uint8Array(binaryLen);
        for (var i = 0; i < binaryLen; i++) {
            var ascii = binaryString.charCodeAt(i);
            bytes[i] = ascii;
        }
        return bytes;
    };

Lastly, we can make an AJAX request to our controller method to get the rendered report, convert the returned Base64 string and then return the rendered report as an attachment using Blobs

$.ajax({
    method: "GET",
    url: '@Url.Action("GenerateReportPDF","ControllerName")',
    async: false,
    cache: false,
    data: { reportName }
}).done(function(result) {
    //if the call was successful
    if (result) {
        buffer = base64ToArrayBuffer(result)
        var file = new Blob([buffer], { type: "application/pdf" })

        var link = document.createElement('a')
        link.href = window.URL.createObjectURL(file)
        link.download = "Report.pdf";
        document.body.appendChild(link)
        link.click()
    }
})