Create a PDF document in Google App Engine

29 Jul 20269 minutes to read

The .NET Core PDF library is used to create, read, and edit PDF documents programmatically without the dependency on Adobe Acrobat. Using this library, you can open and save PDF documents in Google App Engine.

Prerequisites

• A Google Cloud Platform (GCP) account with an active billing account.
• The Google App Engine Admin API must be enabled in your GCP project. To enable it, navigate to APIs & Services > Library, search for App Engine Admin API, and click Enable.
• A basic understanding of Google Cloud Shell and gcloud CLI commands.

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, and 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.Pdf.Net.Core NuGet package as a reference to your project from NuGet.org.

Step 5: Register the Syncfusion^® license key. A trial watermark is added to every page of the generated PDF until a valid key is registered. Include the license key in Program.cs before initializing any Syncfusion^® component:

C#

using Syncfusion.Licensing;

var builder = WebApplication.CreateBuilder(args);
// Register the Syncfusion license
Syncfusion.Licensing.SyncfusionLicenseProvider.RegisterLicense("YOUR LICENSE KEY");

// Add services to the container.
builder.Services.AddControllersWithViews();

var app = builder.Build();

Replace "YOUR LICENSE KEY" with the key from your Syncfusion account. If you do not have one, request a free 30-day trial at https://www.syncfusion.com/sales/communitylicense. For Google App Engine, store the key in app.yaml under env_variables: SyncfusionLicenseKey: YOUR-KEY and read it with builder.Configuration["SyncfusionLicenseKey"] so the key is not committed to source control. Refer to the Syncfusion License documentation to learn about registering the Syncfusion license key in your application.

Step 6: Include the following namespaces in the HomeController.cs file.

C#

using Syncfusion.Pdf;
using Syncfusion.Pdf.Graphics;
using Syncfusion.Pdf.Grid;
using Syncfusion.Drawing;
using System;
using System.Collections.Generic;
using System.IO;

Step 7: 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 8: Add a new button in the Index.cshtml as shown in the following.

CSHTML

@{Html.BeginForm("CreateDocument", "Home", FormMethod.Get);
    {
        <div>
            <input type="submit" value="Create PDF Document" style="width:200px;height:27px" />
        </div>
    }
    Html.EndForm();
}

Step 8a: Add a sample Input.pdf file to the Data folder of your project. Right-click the Data folder, select Add > New Item, and choose an existing PDF file or create a new one. Then, set its Copy to Output Directory property to Copy if newer so the file is included in the publish output.

Step 9: Add a new action method CreateDocument in HomeController.cs and include the following code sample to create PDF document and download it.

C#

public ActionResult CreateDocument()
{
    //Load PDF document as stream.
    using FileStream docStream = new FileStream(@"Data/Input.pdf", FileMode.Open, FileAccess.Read);
    //Load an existing PDF document.
    PdfLoadedDocument document = new PdfLoadedDocument(docStream);

    //Load the existing page.
    PdfLoadedPage loadedPage = document.Pages[0] as PdfLoadedPage;
    //Create PDF graphics for the page.
    PdfGraphics graphics = loadedPage.Graphics;

        //Create a PdfGrid.
        PdfGrid pdfGrid = new PdfGrid();
        //Add values to the list.
        List<object> data = new List<object>();
        data.Add(new { Product_ID = "1001", Product_Name = "Bicycle", Price = "10,000" });
        data.Add(new { Product_ID = "1002", Product_Name = "Head Light", Price = "3,000" });
        data.Add(new { Product_ID = "1003", Product_Name = "Break wire", Price = "1,500" });
        //Assign data source.
        pdfGrid.DataSource = data;
        //Apply built-in table style.
        pdfGrid.ApplyBuiltinStyle(PdfGridBuiltinStyle.GridTable4Accent3);
        //Draw the grid to the page of PDF document.
        pdfGrid.Draw(graphics, new RectangleF(40, 400, loadedPage.Size.Width - 80, 0));

        //Create memory stream.
        MemoryStream stream = new MemoryStream();
        //Save the PDF document to stream.
        document.Save(stream);
        //If the position is not set to '0' then the PDF will be empty.
        stream.Position = 0;
        //Close the document.
        document.Close(true);
        //Download PDF document in the browser.
        return File(stream, "application/pdf", "Sample.pdf");
    }
}

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 view the files and directories within your current Workspace.

BASH

ls

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

BASH

cd Web_Application

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

BASH

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 and return to the terminal, then press Ctrl+C to stop the process.

Publish the application

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

BASH

dotnet publish -c Release

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

BASH

cd bin/Release/net8.0/publish/

Configure app.yaml and docker file

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

BASH

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

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

BASH

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", "Web_Application.dll"]
EOT

Step 3: You can ensure Docker and app.yaml files are added in Workspace.

Deploy to App Engine

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

BASH

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 PDF document as follows. The output will be saved in the bin folder.

Click here to explore the rich set of Syncfusion^® PDF library features.

Next steps

• Create a PDF in Azure App Service on Linux
• Create a PDF in Docker
• Create a PDF in ASP.NET Core
• Open and read an existing PDF document
• Save the generated PDF to a file or stream