Convert Excel document to PDF in AWS Lambda

23 Jul 20256 minutes to read

Syncfusion^® XlsIO is a .NET Core Excel library used to create, read, edit and convert Excel documents programmatically without Microsoft Excel or interop dependencies. Using this library, you can convert a Excel document to PDF in AWS Lambda.

Steps to convert Excel document to PDF in AWS Lambda

Step 1: Create a new AWS Lambda project as follows.

Step 2: Name the application.

Step 3: Select Blueprint as Empty Function and click Finish.

Step 4: Install the following NuGet packages in your application from Nuget.org.

• Syncfusion.XlsIORenderer.Net.Core
• SkiaSharp.NativeAssets.Linux v3.116.1
• HarfBuzzSharp.NativeAssets.Linux v2.8.2.2

NOTE

1. If you’re deploying the application in a Linux environment, refer to the documentation for the required additional NuGet packages.

NOTE

1. Starting with v16.2.0.x, if you reference Syncfusion^® assemblies from trial setup or from the NuGet feed, you also have to add “Syncfusion.Licensing” assembly reference and include a license key in your projects. Please refer to this link to know about registering Syncfusion^® license key in your application to use our components.

Step 5: Create a folder and copy the required data files and include the files to the project.

Step 6: Set the copy to output directory to Copy if newer to all the data files.

Step 7: Include the following namespaces in Function.cs file.

C#

using Syncfusion.XlsIO;
using Syncfusion.XlsIORenderer;
using Syncfusion.Pdf;
using Syncfusion.XlsIO.Implementation;

step 8: Add the following code snippet in Function.cs to convert an Excel document to PDF.

C#

public string FunctionHandler(string input, ILambdaContext context)
{
  using (ExcelEngine excelEngine = new ExcelEngine())
  {
    IApplication application = excelEngine.Excel;
    application.DefaultVersion = ExcelVersion.Xlsx;

    //Initializes the SubstituteFont event to perform font substitution during Excel-to-PDF conversion
    application.SubstituteFont += new SubstituteFontEventHandler(SubstituteFont);

	FileStream excelStream = new FileStream(@"Data/Sample.xlsx", FileMode.Open, FileAccess.Read);
    IWorkbook workbook = application.Workbooks.Open(excelStream);

    //Initialize XlsIO renderer.
    XlsIORenderer renderer = new XlsIORenderer();

    //Convert Excel document into PDF document 
    PdfDocument pdfDocument = renderer.ConvertToPDF(workbook);

    //Create the MemoryStream to save the converted PDF.      
    MemoryStream pdfStream = new MemoryStream();

    //Save the converted PDF document to MemoryStream.
    pdfDocument.Save(pdfStream);
    pdfStream.Position = 0;
    return Convert.ToBase64String(pdfStream.ToArray());
  }
}

private void SubstituteFont(object sender, SubstituteFontEventArgs args)
{
  string filePath = string.Empty;
  FileStream fileStream = null;
  
  if (args.OriginalFontName == "Calibri")
  {
    filePath = Path.GetFullPath(@"Data/calibri.ttf");
    fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read);
    args.AlternateFontStream = fileStream;
  }
  else if (args.OriginalFontName == "Arial")
  {
    filePath = Path.GetFullPath(@"Data/arial.ttf");
    fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read);
    args.AlternateFontStream = fileStream;
  }
  else
  {
    filePath = Path.GetFullPath(@"Data/times.ttf");
    fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read);
    args.AlternateFontStream = fileStream;
  }
}

Step 9: Right-click the project and select Publish to AWS Lambda.

Step 10: Create a new AWS profile in the Upload Lambda Function Window. After creating the profile, add a name for the Lambda function to publish. Then, click Next.

Step 11: In the Advanced Function Details window, specify the Role Name as based on AWS Managed policy. After selecting the role, click the Upload button to deploy your application.

Step 12: After deploying the application, you can see the published Lambda function in AWS console.

Step 13: Edit Memory size and Timeout as maximum in Basic settings of the AWS Lambda function.

Steps to post the request to AWS Lambda

Step 1: Create a new console project.

step 2: Install the following NuGet packages in your application from Nuget.org.

• AWSSDK.Core
• AWSSDK.Lambda
• Newtonsoft.Json

Step 3: Include the following namespaces in Program.cs file.

C#

using Amazon;
using Amazon.Lambda;
using Amazon.Lambda.Model;
using Newtonsoft.Json;

Step 4: Add the following code snippet in Program.cs to invoke the published AWS Lambda function using the function name and access keys.

C#

//Create a new AmazonLambdaClient
AmazonLambdaClient client = new AmazonLambdaClient("awsaccessKeyID", "awsSecreteAccessKey", RegionEndpoint.USEast2);
 
//Create new InvokeRequest with published function name.
InvokeRequest invoke = new InvokeRequest
{
  FunctionName = "MyNewFunction",
  InvocationType = InvocationType.RequestResponse,
  Payload = "\"Test\""
};

//Get the InvokeResponse from client InvokeRequest.
InvokeResponse response = client.Invoke(invoke);
 
//Read the response stream
var stream = new StreamReader(response.Payload);
JsonReader reader = new JsonTextReader(stream);
var serilizer = new JsonSerializer();
var responseText = serilizer.Deserialize(reader);

//Convert Base64String into PDF document
byte[] bytes = Convert.FromBase64String(responseText.ToString());
FileStream fileStream = new FileStream("Sample.pdf", FileMode.Create);
BinaryWriter writer = new BinaryWriter(fileStream);
writer.Write(bytes, 0, bytes.Length);
writer.Close();
System.Diagnostics.Process.Start("Sample.pdf");

By executing the program, you will get the PDF document as follows.

Click here to explore the rich set of Syncfusion^® Excel library (XlsIO) features.

An online sample link to convert an Excel document to PDF in ASP.NET Core.