文件上传到Windows Azure Blob

Question

I am new in Web Development but i am confusing my concepts So I have 2 question

1->What is the difference between my PDF link URL " https://hrbcdev.blob.core.windows.net/uploads/UserForms/reportlayout-130334646861135641.pdf " and any normal PDF Google link " http://www.syncfusion.com/Content/downloads/ebook/Knockoutjs_Succinctly.pdf " because my link downloads the PDF while the other one opens in the Browser.

2-> I am using Windows Azure Blob to upload PDF files to server but when i click on these files it will automatically start download. But i want to open in a new tab instead of download it.... Is there any property during document uploading which tells the server about the file whether it is downloadable or not. Here is my Code:

[HttpPost]
    public virtual ActionResult UploadFile(string kind, int? entityId = null) // optionally receive values specified with Html helper
    {
        // here we can send in some extra info to be included with the delete url 
        var statuses = new List<ViewDataUploadFileResult>();
        var thumbnailKind = AppConfig.KnownKind(kind);
        var uploadLocation = AppConfig.UploadLocation(thumbnailKind);
        for (var i = 0; i < Request.Files.Count; i++)
        {
            var storage = new AzureFileStorage();

            var st = storage.StoreFile(x =>
                            {
                                x.File = Request.Files[i];
                                x.Kind = thumbnailKind;
                                //note how we are adding an additional value to be posted with delete request
                                //and giving it the same value posted with upload
                                x.DeleteUrl = Url.Action(MVC.FileUploader.DeleteFile(entityId));
                                x.StorageDirectory = uploadLocation.Path;
                                x.UrlPrefix = uploadLocation.Url;
                            });


            statuses.Add(st);
        }
        var json = new { files = statuses };
        return Request.Headers["ACCEPT"].Contains("application/json")
            ? Json(json)
            : (ActionResult)Content(json.ToJson());
    }

Answer 1

1->What is the difference between my PDF link URL " https://hrbcdev.blob.core.windows.net/uploads/UserForms/reportlayout-130334646861135641.pdf " and any normal PDF Google link " http://www.syncfusion.com/Content/downloads/ebook/Knockoutjs_Succinctly.pdf " because my link downloads the PDF while the other one opens in the Browser.

Please check the content-type property of the blob. In all likelihood, it is coming back as application/octet-stream (which is the default content type in blob storage). Because the browser (especially Chrome/Firefox) rely on this property to decide whether to show the content inline in the browser or download the file and this is not set as application/pdf , browser decides to download the file. You can change the content-type property of the blob programmatically even after the blob is uploaded.

2-> I am using Windows Azure Blob to upload PDF files to server but when i click on these files it will automatically start download. But i want to open in a new tab instead of download it.... Is there any property during document uploading which tells the server about the file whether it is downloadable or not.

Assuming by downloadable you mean whether user is always prompted to download the blob instead of displaying it inline, recently Windows Azure Storage announced some changes and one of the things they announced is the ability to set Content-Disposition property on a blob. For a blob which you wish to get downloaded all the time, please set its Content-Disposition property to attachment; filename=<blob file name> attachment; filename=<blob file name> and then user will always be prompted to download the blob. You can read more about the new changes here: http://blogs.msdn.com/b/windowsazurestorage/archive/2013/11/27/windows-azure-storage-release-introducing-cors-json-minute-metrics-and-more.aspx .

However if by downloadable you mean securing the blob, please see the answer by @ramiramilu to your 2nd question.

Answer 2

For Question (1) - When you set Content-Dispostion header to inline, browser tries to open the file in itself. If it was set to attachment, then browser will try to open popup for downloading the file. Either in both the cases, file will be downloaded to client browser. So this behaviour purely depends on the type of browsers.

[EDIT] I agree with Gaurav for Question (1), but there is a possibility for blob having Content-Type as application/pdf and Content-Disposition to be attachment.

For Question (2) - You can restrict access for the file by modifying the container access modifiers like Private, public container, public blob. You can set it to private so that the contents of that container will be accessible directly. As per Microsoft - " By default, the container is private and can be accessed only by the account owner. To allow public read access to the blobs in the container, but not the container properties and metadata, use the "Public Blob" option. To allow full public read access for the container and blobs, use the "Public Container" option. "

You can also protect your blobs using SAS - http://www.dotnetcurry.com/showarticle.aspx?ID=901