Error logging in ASP.NET Core Report Writer

If an error occurred in report processing, ASP.NET Core Report writer ReportErrorOccurred event raised. You can register the event and get the report error details from the event arguments to save all logs, stack trace, and error information into a physical file location.

This section explains how to log the detailed error information to your ASP.NET Core application.

This section requires an ASP.NET Core Report Writer application, if you don’t have, then create by referring to the Getting-Started documentation.

1. In Solution Explorer, open the Report Writer Controller file.

2. Add the following sample code to register the report errors in the ReportErrorOccurred event.

   [HttpPost]
   public IActionResult Export(string writerFormat)
   {
       BoldReports.Writer.ReportWriter writer = new BoldReports.Writer.ReportWriter();
       writer.ReportErrorOccurred += Writer_ReportErrorOccurred;
   }
   private void Writer_ReportErrorOccurred(object sender, ReportErrorOccurredEventArgs e)
       {
            // You can register the report errors using event arguments.
       }

3. Create a method in HomeController to write the error text into application folder.

           internal void WriteLogs(string errorMessage)
           {
               string filePath = Path.Combine(_hostingEnvironment.WebRootPath, "ErrorDetails.txt");
               using (StreamWriter writer = new StreamWriter(filePath, true))
               {
                   writer.AutoFlush = true;
                   writer.WriteLine(errorMessage);
               }
           }

4. Invoke the newly created function in ReportErrorOccurred as follows.

       private void Writer_ReportErrorOccurred(object sender, ReportErrorOccurredEventArgs e)
       {
           WriteLogs(string.Format("Class Name: {0} \n Method Name: {1} \n Error Message: {2}", e.ClassName, e.MethodName, e.Message));
       }

   In cases of any issues faced in the report rendering, share the log file to our technical support team to get assistance on that.

5. The final controller is given as follows, you can replace it in your application.

   [HttpPost]
   public IActionResult Export(string writerFormat)
   {
       // Here, we have loaded the sales-order-detail sample report from application the folder wwwroot\Resources.
       FileStream inputStream = new FileStream(_hostingEnvironment.WebRootPath + @"\Resources\sales-order-detail.rdl", FileMode.Open, FileAccess.Read);
       MemoryStream reportStream = new MemoryStream();
       inputStream.CopyTo(reportStream);
       reportStream.Position = 0;
       inputStream.Close();
       BoldReports.Writer.ReportWriter writer = new BoldReports.Writer.ReportWriter();
   
       writer.ReportErrorOccurred += Writer_ReportErrorOccurred;
   
       string fileName = null;
       WriterFormat format;
       string type = null;
   
       if (writerFormat == "PDF")
       {
           fileName = "sales-order-detail.pdf";
           type = "pdf";
           format = WriterFormat.PDF;
       }
       else if (writerFormat == "Word")
       {
           fileName = "sales-order-detail.docx";
           type = "docx";
           format = WriterFormat.Word;
       }
       else if (writerFormat == "CSV")
       {
           fileName = "sales-order-detail.csv";
           type = "csv";
           format = WriterFormat.CSV;
       }
       else
       {
           fileName = "sales-order-detail.xlsx";
           type = "xlsx";
           format = WriterFormat.Excel;
       }
   
       writer.LoadReport(reportStream);
       MemoryStream memoryStream = new MemoryStream();
       writer.Save(memoryStream, format);
   
       // Download the generated export document to the client side.
       memoryStream.Position = 0;
       FileStreamResult fileStreamResult = new FileStreamResult(memoryStream, "application/" + type);
       fileStreamResult.FileDownloadName = fileName;
       return fileStreamResult;
   }
   private void Writer_ReportErrorOccurred(object sender, ReportErrorOccurredEventArgs e)
   {
       WriteLogs(string.Format("Class Name: {0} \n Method Name: {1} \n Error Message: {2}", e.ClassName, e.MethodName, e.Message));
   }
   
   internal void WriteLogs(string errorMessage)
   {
       string filePath = Path.Combine(_hostingEnvironment.WebRootPath, "ErrorDetails.txt");
       using (StreamWriter writer = new StreamWriter(filePath, true))
       {
           writer.AutoFlush = true;
           writer.WriteLine(errorMessage);
       }
   }