Save document to Azure Blob Storage

20 Jan 20247 minutes to read

To save a document to Azure Blob Storage, you can follow the steps below

Step 1: Create a Simple Document Editor Sample in ASP.NET Core

Start by following the steps provided in this link to create a simple Document Editor sample in ASP.NET Core. This will give you a basic setup of the Document Editor component.

Step 2: Modify the DocumentEditorController.cs File in the Web Service Project

• Create a web service project in .NET Core 3.0 or above. You can refer to this link for instructions on how to create a web service project.

• Open the DocumentEditorController.cs file in your web service project.

• Import the required namespaces at the top of the file:

using System.IO;
using Azure.Storage.Blobs;
using Azure.Storage.Blobs.Specialized;

• Add the following private fields and constructor parameters to the DocumentEditorController class, In the constructor, assign the values from the configuration to the corresponding fields

private readonly string _storageConnectionString;
private readonly string _storageContainerName;
private readonly ILogger<DocumentEditorController> _logger;

public DocumentEditorController(IConfiguration configuration, ILogger<DocumentEditorController> logger)
{
  _storageConnectionString = configuration.GetValue<string>("connectionString");
  _storageContainerName = configuration.GetValue<string>("containerName");
  _logger = logger;
}

• Create then ‘SaveToAzure’ method to save the downloaded documents to Azure Blob Storage container

[HttpPost("SaveToAzure")]
[Microsoft.AspNetCore.Cors.EnableCors("MyPolicy")]
[Route("[controller]/SaveToAzure")]
//Post action for downloading the documents

public void Download(IFormCollection data)
{
  if (data.Files.Count == 0)
    return;

  BlobServiceClient blobServiceClient = new BlobServiceClient(_storageConnectionString);
  BlobContainerClient containerClient = blobServiceClient.GetBlobContainerClient(_storageContainerName);

  IFormFile file = data.Files[0];
  string documentName = this.GetValue(data, "documentName");
  string result = Path.GetFileNameWithoutExtension(documentName);

  // Get a reference to the blob
  BlobClient blobClient = containerClient.GetBlobClient(result + "_downloaded.docx");

  Stream stream = new MemoryStream();
  file.CopyTo(stream);

  // Upload the document to Azure Blob Storage
  blobClient.Upload(stream, true);
}

private string GetValue(IFormCollection data, string key)
{
    if (data.ContainsKey(key))
    {
        string[] values = data[key];
        if (values.Length > 0)
        {
            return values[0];
        }
    }
    return "";
}

• Open the appsettings.json file in your web service project, Add the following lines below the existing "AllowedHosts" configuration

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft.AspNetCore": "Warning"
    }
  },
  "AllowedHosts": "*",
  "connectionString": "*Your Connection string from Azure*",
  "containerName": "*Your container name in Azure*"
}

NOTE

Replace Your Connection string from Azure with the actual connection string for your Azure Blob Storage account and Your container name in Azure with the actual container name

Step 3: Modify the Index.cshtml File in the Document Editor sample

In the client-side, to export the document into blob the document using saveAsBlob and sent to server-side for saving in Azure Blob Storage container.

CSHTML

<ejs-button id="export">Save to Azure Blob Storage</ejs-button>
<ejs-documenteditorcontainer id="container"></ejs-documenteditorcontainer>
<script>
    var documenteditor;
    document.addEventListener('DOMContentLoaded', function () {
        var documenteditorElement = document.getElementById("container");        
        container = documenteditorElement.ej2_instances[0];
        document.getElementById('export').addEventListener('click', function () {
            container.documentEditor.saveAsBlob('Docx').then((blob) => {
                var exportedDocument = blob;
                //Now, save the document where ever you want.
                var formData = new FormData();
                formData.append('documentName', container.documentEditor.documentName);
                formData.append('data', exportedDocument);
                /* tslint:disable */
                var req = new XMLHttpRequest();
                // Replace your running Url here
                req.open(
                    'POST',
                    window.baseurl + 'api/documenteditor/SaveToAzure',
                    true
                );
                req.onreadystatechange = () => {
                    if (req.readyState === 4) {
                        if (req.status === 200 || req.status === 304) {
                            console.log('Saved sucessfully');
                        }
                    }
                };
                req.send(formData);
            });
        });
    }); 
</script>

Document-editor.cs

public ActionResult Default()
{
    return View();
}

NOTE

The Azure.Storage.Blobs NuGet package must be installed in your application to use the previous code example.