Open and save PDF document in Google App Engine

1 Aug 20238 minutes to read

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

Set up App Engine

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

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

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

gcloud auth list

Authentication for App Engine

Step 4: Click the Authorize button.
Click 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.
Create ASP.NET Core Web application in Visual Studio

Step 2: Configure your new project according to your requirements.
Create ASP.NET Core Web application in Visual Studio

Step 3: Click the Create button.
Create ASP.NET Core Web application in Visual Studio

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

NOTE

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

Step 5: Include the following namespaces in the HomeController.cs file.

using Syncfusion.Pdf;
using Syncfusion.Pdf.Graphics;
using Syncfusion.Drawing;
using System.IO;

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 in the following.

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

Step 8: Add a new action method OpenAndSaveDocument in HomeController.cs and include the below code snippet to open an existing PDF document.

//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);

step 9: Add the following code example to add paragraph and table to the PDF document.

//Get the first page from a document.
PdfLoadedPage page = document.Pages[0] as PdfLoadedPage;
//Create PDF graphics for the page.
PdfGraphics graphics = page.Graphics;
//Create a PdfGrid.
PdfGrid pdfGrid = new PdfGrid();

//Add values to the list.
List<object> data = new List<object>();
Object row1 = new { Product_ID = "1001", Product_Name = "Bicycle", Price = "10,000" };
Object row2 = new { Product_ID = "1002", Product_Name = "Head Light", Price = "3,000" };
Object row3 = new { Product_ID = "1003", Product_Name = "Break wire", Price = "1,500" };
data.Add(row1);
data.Add(row2);
data.Add(row3);

//Add list to IEnumerable.
IEnumerable<object> dataTable = data;
//Assign data source.
pdfGrid.DataSource = dataTable;
//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, page.Size.Width - 80, 0));

Step 10: Add the following code example to save the PDF document.

//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 Word document in the browser.
return File(stream, "application/pdf", "Sample.pdf");

Move application to App Engine

Step 1: Open the Cloud Shell editor.

Cloud Sell editor

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

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.

ls

ls command

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

cd Open-and-save-Word-document

Project Folder

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

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

Run Application

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

Preview on Port

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

Output Button

Step 8: Close the preview page and return to the terminal then press Ctrl+C which will typically stop the process.

Work space

Publish the application

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

dotnet publish -c Release

Release

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

cd bin/Release/net6.0/publish/

Publish Folder

Configure app.yaml and docker file

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

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

yaml file to publish

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

cat <<EOT >> Dockerfile
FROM mcr.microsoft.com/dotnet/aspnet:6.0
RUN apt-get update -y && apt-get install libfontconfig -y
ADD / /app
EXPOSE 8080
ENV ASPNETCORE_URLS=http://*:8080
WORKDIR /app
ENTRYPOINT [ "dotnet", "Open-and-save-Word-document.dll"]
EOT

Docker file to publish

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

Docker file

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.

gcloud app deploy --version v0

Deploy

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

Output Console

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.

Output PDF Document

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