998246: Added UG content for load excel files from google drive into spreadsheet

Document-Processing/Excel/Spreadsheet/Blazor/open-and-save.md

@@ -72,6 +72,117 @@ An Excel file encoded as a Base64 string can be loaded into the Spreadsheet comp
 {% endhighlight %}
 {% endtabs %}
 
+### Open an Excel file from Google Drive
+To load an Excel file from `Google Drive` in the Blazor Spreadsheet, follow the steps below.
+
+**Prerequisites:**
+- [Google Cloud project](https://developers.google.com/workspace/guides/create-project) in the Google Cloud Console.
+- [Service account](https://cloud.google.com/iam/docs/service-accounts-create) within the GCP project.
+- [Service account key](https://cloud.google.com/iam/docs/keys-create-delete) (JSON) available on disk.
+- [Google Drive API enabled](https://console.cloud.google.com/apis/library/drive.googleapis.com) for the project.
+- [Google Drive account](https://drive.google.com/) with access to the file to download.
+- [Google.Apis.Drive.v3](https://www.nuget.org/packages/Google.Apis.Drive.v3) NuGet package installed in your project to access Google Drive API.
+
+**Step 1:** Install required NuGet packages
+
+To use Google Drive with the Blazor Spreadsheet, install the following packages:
+
+- [Google.Apis.Drive.v3](https://www.nuget.org/packages/Google.Apis.Drive.v3) — to access the Google Drive API
+- [Syncfusion.Blazor.Spreadsheet](https://www.nuget.org/packages/Syncfusion.Blazor.Spreadsheet) — to use the Syncfusion Blazor Spreadsheet component
+
+**Step 2:** Include the following namespaces in the **Index.razor** file
+
+Import the required namespaces at the top of the file:
+
+```
+@using Google.Apis.Auth.OAuth2;
+@using Google.Apis.Drive.v3;
+@using Google.Apis.Services;
+@using Syncfusion.Blazor.Spreadsheet;
+@using System.IO;
+```
+
+**Step 3:** Download the Excel file, convert to bytes, and prepare for binding
+
+Add the below code example to download the `Google Drive` file using the Drive API, convert the stream to a byte array, and bind it to the Spreadsheet's [DataSource](https://help.syncfusion.com/cr/blazor/Syncfusion.Blazor.Spreadsheet.SfSpreadsheet.html#Syncfusion_Blazor_Spreadsheet_SfSpreadsheet_DataSource) property.
+
+{% tabs %}
+{% highlight razor %}
+
+@page "/"
+
+@if (IsSpreadsheetDataLoaded)
+{
+    <SfSpreadsheet DataSource="DataSourceBytes">
+        <SpreadsheetRibbon></SpreadsheetRibbon>
+    </SfSpreadsheet>
+}
+@code{
+
+    public byte[] DataSourceBytes { get; set; }
+
+    // Flag to indicate whether the spreadsheet data has been loaded and is ready for rendering
+    public bool IsSpreadsheetDataLoaded { get; set; }
+
+    protected override async Task OnInitializedAsync()
+    {
+        //Download the document from Google Drive
+        MemoryStream stream = await GetDocumentFromGoogleDrive();
+
+        //Set the position as '0'
+        stream.Position = 0;
+
+        // Convert the MemoryStream to a byte array to be used as the DataSource
+        DataSourceBytes = stream.ToArray();
+
+        // Set the flag to true to indicate that the spreadsheet data is ready
+        IsSpreadsheetDataLoaded = true;
+    }
+
+    // Download file from Google Drive
+    public async Task<MemoryStream> GetDocumentFromGoogleDrive()
+    {
+        //Define the path to the service account key file
+        string serviceAccountKeyPath = "Your_service_account_key_path";
+
+        //Specify the file ID of the file to download
+        string fileID = "Your_file_id";
+
+        try
+        {
+            //Authenticate the Google Drive API access using the service account key
+            GoogleCredential credential = GoogleCredential.FromFile(serviceAccountKeyPath).CreateScoped(DriveService.ScopeConstants.Drive);
+
+            //Create the Google Drive service
+            DriveService service = new DriveService(new BaseClientService.Initializ()
+            {
+                HttpClientInitializer = credential
+            });
+
+            //Create a request to get the file from Google Drive
+            var request = service.Files.Get(fileID);
+
+            //Download the file into a MemoryStream
+            MemoryStream stream = new MemoryStream();
+            await request.DownloadAsync(stream);
+
+            return stream;
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine($"Error retrieving document from Google Drive: {ex.Message}");
+            throw;
+        }
+    }
+}
+
+{% endhighlight %}
+{% endtabs %}
+
+N> Replace **Your_file_id** with the actual Google Drive file ID, and **Your_service_account_key_path** with the actual path to your service account key JSON file.
+
+N> The **FileID** is the unique identifier for a Google Drive file. For example, if the file URL is: `https://drive.google.com/file/d/abc123xyz456/view?usp=sharing`, then the file ID is `abc123xyz456`.
+
 ### Supported file formats
 The Spreadsheet component supports opening the following file formats:
 * Microsoft Excel Workbook (.xlsx)