I need to have force download action after clicking on Sitecore media link. I didn't find any useful Sitecore advance how to achieve that.
In Sitecore configuration you can define which mime types will be force downloaded. But problem is, if you want to do it for images. Because if you do this
<mediaType name="JPEG image" extensions="jpg, jpeg, jpe">
<mimeType>image/jpeg</mimeType>
<forceDownload>true</forceDownload>
</mediaType>
all images will disappear because of browser won't be able to present them in HTML!
How to make all Sitecore media files force downloaded on click?
After some investigation in Sitecore's code with decompiler I decide that the best way is to extend Sitecore MediaRequestHandler.
But how to recognize if I want to present an image and download an image? We have to add query string parameter to URL, something like "dl=1"
public class MediaRequestHandler : Sitecore.Resources.Media.MediaRequestHandler, System.Web.SessionState.IRequiresSessionState
{
protected override bool DoProcessRequest(HttpContext context, MediaRequest request, Media media)
{
// identify query string param from requested URL
bool isDownload = Utils.UrlUtils.HasQueryParam(context.Request.Url, "dl", "1");
if (isDownload)
{
using (MediaStream stream = media.GetStream())
{
// we have to check if file is not already force downloaded by Sitecore
if (!stream.ForceDownload)
{
string mediaName = media.MediaData.MediaItem.Name + "." + media.MediaData.Extension;
context.Response.AddHeader("Content-Disposition", "attachment; filename=\"" + mediaName + "\"");
}
context.Response.AddHeader("Content-Length", stream.Length.ToString());
}
}
// it must be called after all logic
return base.DoProcessRequest(context, request, media);
}
}
Some remarks for the code:
all logic must be before calling original DoProcessRequest method because after processing it will flush all headers to response (!)
there must be query string parameter which decide if to force download file or not
some mime types already have "forcedownload" attribute from configuration so you have to check it to avoid duplicate header "Content-Disposition" (this cause problem in Chrome, downloaded file will have extension something like "filename-, attachment")
Related
I use dotnetbrowser to display a web browser on a old windows framework.
have you an idea to define the download path ?
My dotnetbroser is enable, i can show my webpage but i don't found in documentation or exemple how define this simple download path.
The only exemple that i've found is about the download event detection.
I use WPF in C#
Thanks.
The DotNetBrowser.DownloadItem.DestinationFile property is writable and can be used to configure the path to store the file.
To set this property in your application, you need to subclass the DotNetBrowser.DefaultDownloadHandler and implement its AllowDownload(DownloadItem) method. Then you need to configure your download handler as shown in the documentation article: File Download
You can also configure and use DotNetBrowser.WPF.WPFDefaultDownloadHandler instance to show file chooser and select the path to store the file.
This is a solution
Défine your browser like variable :
BrowserView myBrowserView;
Browser myBrowser;
Create the browser properly :
this.myBrowser = BrowserFactory.Create();
this.myBrowserView = new WPFBrowserView(this.myBrowser);
Create event detection for download
this.myDowloadHandler = new SampleDownloadHandler();
this.myBrowser.DownloadHandler = myDowloadHandler;
Add it to a container, here, a grid
grid_navigateur.Children.Add((UIElement)myBrowserView.GetComponent());
Now we are going to use our "SampleDownloadHandler" class
class SampleDownloadHandler : DownloadHandler
{
public bool AllowDownload(DownloadItem download)
{
download.DestinationFile = "exemple\of\path\whith\file\name";
download.DownloadEvent += delegate(object sender, DownloadEventArgs e)
{
DownloadItem downloadItem = e.Item;
if (downloadItem.Completed)
{
System.Windows.MessageBox.Show("Download complete");
}
};
return true;
}
My personalisated class define path and name of the file who is download and pop a message when is over.
(to found the file name, you do to cut the string download.DestinationFile after the last )
I have this controller methods that depending on the parameters introduced by the user downloads a certain PDF file and shows a view with its different pages converted to PNG.
So the way I approached it works like this:
First I map a method to receive the post data sent by the user, then generate the URL of the actual PDF converter and pass it to the model:
#RequestMapping(method = RequestMethod.POST)
public String formPost(Model model, HttpServletRequest request) {
//Gather parameters and generate PDF url
Long idPdf = Long.parseLong(request.getParam("idPdf"));
//feed the jsp the url of the to-be-generated image
model.addAttribute("image", "getImage?idPdf=" + idPdf);
}
Then in getImageMethod I download the PDF and then generate a PNG out of it:
#RequestMapping("/getImage")
public HttpEntity<byte[]> getPdfToImage(#RequestParam Long idPdf) {
String url = "myPDFrepository?idPDF=" + idPdf;
URL urlUrl = new URL(url);
URLConnection urlConnection;
urlConnection = urlUrl.openConnection();
InputStream is = urlConnection.getInputStream();
return PDFtoPNGConverter.convert(is);
}
My JSP just has an img tag that refers to this url:
<img src="${image}" />
So far this work perfectly. But now I need to allow the possibility of viewing multi page PDFs, converted as PNGS, each of them in a different page. So I would add a page parameter, then feed my model with the image url including that page parameter, and in my getImage method I would convert only that page.
But the way it is implemented, I would be downloading the PDF again for each page, plus an additional time for the view, so it can find out whether this specific PDF has more pages and then show the "prev" and "next" buttons.
What would be a good way to preserve the same file during these requests, so I download it just once? I thought about using temp files but then managing its deletion might be a problem. So maybe storing the PDF in the session would be a good solution? I don't even know if this is good practice or not.
I am using Spring MVC by the way.
I think the simplest way would be using spring cache abstraction. Look at tutorial and will need to change your code a little: move logic that load pdf to separate class.
it will looks like:
interface PDFRepository {
byte[] getImage(long id);
}
#Repository
public class PDFRepositoryImpl implements PDFRepository {
#Cacheable
public byte[] getImage(long id) {
String url = "myPDFrepository?idPDF=" + idPdf;
URL urlUrl = new URL(url);
URLConnection urlConnection;
urlConnection = urlUrl.openConnection();
InputStream is = urlConnection.getInputStream();
return PDFtoPNGConverter.convert(is);
}
}
You will get pluggable cache implementation support and good cache expiration management.
I am getting a list of objects in Windows Phone, and show them in a listbox with databinding.
some image urls are not valid, so after every object is added in the list, i run the following code to check and replace, if not valid
private void CheckLinkUrl(Person p)
{
Uri filePath = new Uri(p.img_url);
string correct = p.img_url;
HttpWebRequest fileRequest = HttpWebRequest.CreateHttp(filePath);
fileRequest.Method = "HEAD";
fileRequest.BeginGetResponse(result =>
{
HttpWebRequest resultInfo = (HttpWebRequest)result.AsyncState;
HttpWebResponse response;
try
{
response = (HttpWebResponse)resultInfo.EndGetResponse(result);
}
catch (Exception e)
{
p.img_url = "http://somethingelse.com/image.jpg";
}
}, fileRequest);
}
the problem is that it is very slow, it takes sometimes 2 minutes+ to load every image (although the UI remains responsive, and everything else is displayed immediately in the listbox, apart from the images)
am I doing something wrong? can i get it to run faster?
EDIT:
I tried using the imagefailed event and replace the link, no improvement at the speed of loading the pics
What I have done to avoid this problem in my application is, I have loaded the items with a default Image, The image source is binded to a property in my result item of type ImageSource. By default it returns the default image. After processing or download completion the imagesource value changes to the new Image triggering the NotifyPropertyChanged event and hence it is automatically reflected on the UI. I hope it helps you.
I am using the Background Transfer to upload Photographs to my Web Service. As the Photograph uploads can consume significant time and memory, I thought it might be a nice idea to use the background transfer request to accomplish this. After the photo is uploaded, I want to obtain the Id of the uploaded photo and then use it for post-processing. However, it turns out I can't do that in a background transfer request.
Per my understanding, Background Transfer works using the following logic ONLY:
You have to obtain the file you want to upload and then save/copy it to your app's Isolated Storage under the folder: shared/transfers. This is extremely important. Apparently, using file in a different location didn't work for me. Maybe it isn't the shared/transfers as much as it is a 'relative' path. But I would stick to the same conventions.
After you have saved the file in that location, your background request can be created based on that. It doesn't look like you can pass POST CONTENT other than the file contents, so any other parameters like file name, mime type etc. will need to be passed as QUERY String parameters only. I can understand this, but it would've been nice if I could pass both as POST Content. I don't think HTTP has a limitation on how this works.
Here is some code for creating a request using Hammock:
string url = App.ZineServiceAuthority + "articles/save-blob?ContainerName={0}&MimeType={1}&ZineId={2}&Notes={3}&IsPrivate={4}&FileName={5}";
url = String.Format(url, userId, "image/jpg", ZineId, txtStatus.Text, true, UploadFileName);
var btr = new BackgroundTransferRequest(new Uri(url, UriKind.Absolute));
btr.TransferPreferences = TransferPreferences.AllowCellularAndBattery;
btr.Method = "POST";
btr.Headers.Add("token", IsolatedStorageHelper.GetTravzineToken());
btr.UploadLocation = new Uri(#"/shared\transfers/" + UploadFileName, UriKind.Relative);
btr.TransferStatusChanged += new EventHandler<BackgroundTransferEventArgs>(btr_TransferStatusChanged);
btr.TransferProgressChanged += new EventHandler<BackgroundTransferEventArgs>(btr_TransferProgressChanged);
BackgroundTransferService.Add(btr);
In my case, I am literally passing all the necessary parameters using the query string. On a successful save, my Web Service returns back the Id of the Photo I just uploaded. However:
There is NO way (or at least I know of) to obtain and evaluate the RESPONSE. The Background Transfer Request Event handlers do not expose a RESPONSE.
Here are my event handlers:
void btr_TransferProgressChanged(object sender, BackgroundTransferEventArgs e)
{
bool isUploading = e.Request.TotalBytesToSend > 0 ? true : false;
lblStatus.Text = isUploading ? "Uploading" + e.Request.BytesSent.ToString() + " sent" : "Done";
}
void btr_TransferStatusChanged(object sender, BackgroundTransferEventArgs e)
{
if (e.Request.TransferStatus == TransferStatus.Completed)
{
using (IsolatedStorageFile iso =
IsolatedStorageFile.GetUserStoreForApplication())
{
if (iso.FileExists(e.Request.UploadLocation.OriginalString))
iso.DeleteFile(e.Request.UploadLocation.OriginalString);
}
BackgroundTransferService.Remove(e.Request);
if (null != e.Request.TransferError)
{
MessageBox.Show(e.Request.TransferError.Message);
}
else
{
lblStatus.Text = "Done baby done";
}
}
}
So now my question is, how does anyone do any sort of POST Processing in such scenarios?
Can anyone please tell me the line of thought behind designing such an inflexible class?
Any thoughts on how I could get around this issue would be appreciated.
Also, does anyone have any working examples of a homegrown BackgroundTransfer?
Haven't tried it but why not set a download location like this:
btr.DownloadLocation = "myDownloadFile.html";
btr.UploadLocation = "myUploadFile.jpg";
...
If the request is completed read the file "myDownloadFile.html" where your response has been stored and delete it afterwards.
I'm having a problem using Winnovatives PDFConverter on pages that are protected by Extranet security (which is based on ASP.Net Membership).
I've tried several different approaches, but the following I can get to work on my local machine, but not anywhere else.
Code for login page, this code should bypass the login process for:
// check that the current "user" isn't logged in and is the Winnovative UserAgent
if (!Sitecore.Context.IsLoggedIn && Request.UserAgent.Contains(".NET CLR"))
{
//Login with a dummy user I've created
Sitecore.Security.Authentication.AuthenticationManager.Login("extranet\\pdf", "pdf", true);
//redirect to former page
}
The page that generates the PDF uses this code:
private void PDFPrint(string url)
{
PdfConverter pdfConverter = new PdfConverter();
pdfConverter.LicenseKey = "our license";
url = Request.Url.Scheme + "://" + Request.Url.Host + url;
byte[] downloadBytes = pdfConverter.GetPdfFromUrlBytes(url);
HttpResponse response = HttpContext.Current.Response;
response.Clear();
response.AddHeader("Content-Type", "binary/octet-stream");
response.AddHeader("Content-Disposition", "attachment; filename=" + Sitecore.Context.Item.Name + ".pdf" + "; size=" + downloadBytes.Length.ToString());
response.Flush();
response.BinaryWrite(downloadBytes);
response.Flush();
response.End();
}
The Exception I'm getting is this:
"Could not get the metafile from url. Could not get image from url.The URL is not accessible.."
I've also tried this trick from the Winnovative FAQ to no avail:
http://www.winnovative-software.com/FAQ.aspx#authenticationQ
I've also tried to use WebClient or HttpWebRequest to retrieve the content.
But nothing I do seems to work other than locally.
Basically I want to create a way of either getting Winnovatives converter to use the current logged in user, my custom "pdf" user og some other way of getting the html from the response.
I hope this question isn't too vague, but I find it kinda hard to ask. But basically I want to get some html content from a page on a Sitecore solution I control, which is protected by Sitecore normal Extranet security. This html content should be in string or byte[] format.
Help me Stackoverflowers, you're my only hope! :P
I contacted Sitecore to ask if they had a solution.
Their solution was to create a Processor that would set an active user based on some criteria.
This is the code I made for my site (it's probably not the best solution as UserAgent can be spoofed):
public class MyResolver : HttpRequestProcessor
{
// Methods
public override void Process(HttpRequestArgs args)
{
var userAgent = args.Context.Request.UserAgent ?? "";
SiteContext site = Sitecore.Context.Site;
if (site.Name == "site_name_in_webconfig" && userAgent.Contains("this_should_only_be_in_thepdfcreators_userAgent"))
{
Sitecore.Security.Accounts.User pdfuser = Sitecore.Security.Accounts.User.FromName("extranet\\theUser", true);
AuthenticationManager.SetActiveUser(pdfuser);
}
}
}
and then add the following to the web.config, before the UserResolver:
<processor type="Namespace.MyResolver, Assembly" />
I hope this will help some others out there.
I've found a similar issue on the ASP.NET forums and the answer to that was to use a newer version of the PDF tool: SessionState Problems ?