Loading and Saving Excel files in Google App Engine

24 Jul 20267 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. This article explains how to load and save an Excel file in Google App Engine using Syncfusion XlsIO.

Prerequisites

• A Google Cloud account with permissions to create App Engine applications and enable the App Engine API.
• Visual Studio 2019 or later with the ASP.NET and web development workload installed.
• A Syncfusion^® license key. Refer to How to register the Syncfusion license key for details.

Set up App Engine

Step 1: Open the Google Cloud Console and click the Activate Cloud Shell button.

Step 2: Click the Cloud Shell Editor button to view the Workspace.

Step 3: Open Cloud Shell Terminal, run the following command to confirm authentication.

CLI

gcloud auth list

Step 4: Click the Authorize button.

Create an application for App Engine

Step 1: Open Visual Studio and select the ASP.NET Core Web app (Model-View-Controller) template.

Step 2: Configure your new project according to your requirements.

Step 3: Click the Create button.

Step 4: Install the Syncfusion.XlsIO.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 HomeController.cs file.

C#

using Syncfusion.XlsIO;

Step 6: A default action method named Index will be present in HomeController.cs. Right click on Index method and select Go To View where you will be directed to its associated view page Index.cshtml.

Step 7: Add a new button in the Index.cshtml as shown below.

C#

@{
    Html.BeginForm("LoadAndSaveDocument", "Home", FormMethod.Get);
    {
        <div>
            <input type="submit" value="Load and Save Document" style="width:230px;height:27px" />
        </div>
    }
    Html.EndForm();
}

Step 8: Add a new action method LoadAndSaveDocument in HomeController.cs and include the below code snippet to load and save an existing Excel document.

C#

using (ExcelEngine excelEngine = new ExcelEngine())
{
    IApplication application = excelEngine.Excel;
    application.DefaultVersion = ExcelVersion.Xlsx;

    //Load an existing Excel document
    IWorkbook workbook = application.Workbooks.Open("Data/InputTemplate.xlsx");

    //Access first worksheet from the workbook.
    IWorksheet worksheet = workbook.Worksheets[0];

    //Set Text in cell A3.
    worksheet.Range["A3"].Text = "Hello World";

    //Save the Excel to MemoryStream 
    MemoryStream outputStream = new MemoryStream();
    workbook.SaveAs(outputStream);

    //Set the position
    outputStream.Position = 0;

    //Download the Excel document in the browser.
    return File(outputStream, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", "Sample.xlsx");
}

Move application to App Engine

Step 1: Open the Cloud Shell editor.

Step 2: Drag and drop the sample from your local machine to Workspace.

NOTE

If you have your sample application in your local machine, drag and drop it into the Workspace. If you created the sample using the Cloud Shell terminal command, it will be available in the Workspace.

Step 3: Open the Cloud Shell Terminal and run the following command to list the files and directories within your current Workspace.

CLI

ls

Step 4: Run the following command to navigate to the sample you want to run.

CLI

cd LoadingandSaving

Step 5: To ensure that the sample is working correctly, please run the application using the following command.

CLI

dotnet run --urls=http://localhost:8080

Step 6: Verify that the application is running properly by accessing the Web View -> Preview on port 8080.

Step 7: Now you can see the sample output on the preview page.

Step 8: Close the preview page, return to the terminal, and press Ctrl+C to stop the running process.

Publish the application

Step 1: Run the following command in Cloud Shell Terminal to publish the application.

CLI

dotnet publish -c Release

Step 2: Run the following command in Cloud Shell Terminal to navigate to the publish folder.

CLI

cd bin/Release/net8.0/publish/

Configure app.yaml and Dockerfile

Step 1: Add the app.yaml file to the publish folder with the following contents.

CLI

cat <<EOT >> app.yaml
env: flex
runtime: custom   
EOT

Step 2: Add the Dockerfile to the publish folder with the following contents.

CLI

cat <<EOT >> Dockerfile
FROM mcr.microsoft.com/dotnet/aspnet:8.0
RUN apt-get update -y && apt-get install libfontconfig -y
ADD / /app
EXPOSE 8080
ENV ASPNETCORE_URLS=http://*:8080
WORKDIR /app
ENTRYPOINT [ "dotnet", "LoadingandSaving.dll"]
EOT

Step 3: Verify that the Dockerfile and app.yaml files are present in the Workspace.

Deploy to App Engine

Step 1: To deploy the application to App Engine, run the following command in the Cloud Shell Terminal. Afterwards, retrieve the deployed URL from the Cloud Shell Terminal.

CLI

gcloud app deploy --version v0

Step 2: Open the URL to access the application, which has been successfully deployed.

You can download a complete working sample from GitHub.

By executing the program, you will get the Excel document as follows. The output will be saved in bin folder.

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