Open and save Presentation in Azure Functions (Flex Consumption)

29 Jun 202610 minutes to read

Syncfusion^® PowerPoint is a .NET Core PowerPoint library used to create, read, edit and convert PowerPoint documents programmatically without Microsoft PowerPoint or interop dependencies. Using this library, you can open and save Presentation in Azure Functions deployed on Flex (Consumption) plan.

Steps to open and save Presentation in Azure Functions (Flex Consumption)

Step 1: Create a new Azure Functions project.

Step 2: Create a project name and select the location.

Step 3: Select function worker as .NET 8.0 (Long Term Support) (isolated worker) and target Flex/Consumption hosting suitable for isolated worker.

Step 4: Install the Syncfusion.Presentation.Net.Core NuGet package as a reference to your project from NuGet.org.

NOTE

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: Include the following namespaces in the Function1.cs file.

C#

using Syncfusion.Presentation;

Step 6: Add the following code snippet in Run method of Function1 class to perform open the existing Presentation in Azure Functions and return the resultant PowerPoint Presentation to client end.

C#

public async Task<IActionResult> Run([HttpTrigger(AuthorizationLevel.Function, "post")] HttpRequest req)
    {
        try
        {
            // Create a memory stream to hold the incoming request body (PowerPoint Presentation bytes)
            await using MemoryStream inputStream = new MemoryStream();
            // Copy the request body into the memory stream
            await req.Body.CopyToAsync(inputStream);
            // Check if the stream is empty (no file content received)
            if (inputStream.Length == 0)
                return new BadRequestObjectResult("No file content received in request body.");
            // Reset stream position to the beginning for reading
            inputStream.Position = 0;
            // Load the PowerPoint Presentation from the stream
            using IPresentation pptxDoc = Presentation.Open(inputStream);
            //Gets the first slide from the PowerPoint presentation
            ISlide slide = pptxDoc.Slides[0];
            //Gets the first shape of the slide
            IShape shape = slide.Shapes[0] as IShape;
            //Change the text of the shape
            if (shape.TextBody.Text == "Company History")
                shape.TextBody.Text = "Company Profile";
            MemoryStream memoryStream = new MemoryStream();
            //Saves the PowerPoint document file.
            pptxDoc.Save(memoryStream);
            memoryStream.Position = 0;
            var bytes = memoryStream.ToArray();
            return new FileContentResult(bytes, "application/vnd.openxmlformats-officedocument.presentationml.presentation")
            {
                FileDownloadName = "presentation.pptx"
            };
        }
        catch(Exception ex)
        {
            // Log the error with details for troubleshooting
            _logger.LogError(ex, "Error open and save PowerPoint Presentation.");
            // Prepare error message including exception details
            var msg = $"Exception: {ex.Message}\n\n{ex}";
            // Return a 500 Internal Server Error response with the message
            return new ContentResult { StatusCode = 500, Content = msg, ContentType = "text/plain; charset=utf-8" };
        }
    }

Step 7: Right click the project and select Publish. Then, create a new profile in the Publish Window.

Step 8: Select the target as Azure and click Next button.

Step 9: Select the specific target as Azure Function App and click Next button.

Step 10: Select the Create new button.

Step 11: Click Create button.

Step 12: After creating app service then click Finish button.

Step 13: Click the Publish button.

Step 14: Publish has been succeed.

Step 15: Now, go to Azure portal and select the App Services. After running the service, click Get function URL by copying it. Then, paste it in the below client sample (which will request the Azure Functions, to perform open and save Presentation using the template PowerPoint document). You will get the output PowerPoint Presentation as follows.

Steps to post the request to Azure Functions

Step 1: Create a console application to request the Azure Functions API.

Step 2: Add the following code snippet into Main method to post the request to Azure Functions with template PowerPoint document and get the resultant PowerPoint Presentation.

C#

static async Task Main()
    {
        try
        {
            Console.Write("Please enter your Azure Functions URL : ");
            string url = Console.ReadLine();
            if (string.IsNullOrEmpty(url)) return;
            // Create a new HttpClient instance for sending HTTP requests
            using var http = new HttpClient();
            // Read all bytes from the input PowerPoint file 
            byte[] bytes = await File.ReadAllBytesAsync(@"Data/Input.pptx");
            // Wrap the file bytes into a ByteArrayContent object for HTTP transmission
            using var content = new ByteArrayContent(bytes);
            // Set the content type header to indicate binary data
            content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("application/octet-stream");
            // Send a POST request to the provided Azure Functions URL with the file content
            using var res = await http.PostAsync(url, content);
            // Read the response body as a byte array
            var resBytes = await res.Content.ReadAsByteArrayAsync();
            // Extract the media type from the response headers
            string mediaType = res.Content.Headers.ContentType?.MediaType ?? string.Empty;
            // Decide the output file path the response is an image or txt         
            string outputPath = mediaType.Contains("presentation", StringComparison.OrdinalIgnoreCase)
                || mediaType.Contains("powerpoint", StringComparison.OrdinalIgnoreCase)
                || mediaType.Equals("application/vnd.openxmlformats-officedocument.presentationml.presentation", StringComparison.OrdinalIgnoreCase)
                ? Path.GetFullPath(@"../../../Output/Output.pptx")
                : Path.GetFullPath(@"../../../function-error.txt");
            // Write the response bytes to the output file 
            await File.WriteAllBytesAsync(outputPath, resBytes);
            Console.WriteLine($"Saved: {outputPath}");
        }
        catch (Exception ex)
        {
            throw;
        }
    }

From GitHub, you can download the console application and Azure Functions Flex Consumption.

Looking for the full .NET PowerPoint Library component overview, features, pricing, and documentation? Visit the .NET PowerPoint Library page.