I am developing a windows phone application which allows user to download files from server. The user can select multiple files simultaneously for download. It works perfectly when the user stay on current page until download completed. If the user navigate to other pages when the file download is in progress the download stops. The download should continue even if the user navigate to other pages.
Also when the application exits the download stops. When the user starts the application again the pending files should automatically start download.
How can I do these?
If the files are large you should be using BackgroundTransferRequest, which will continue even if the application is not running and you can still track their progress.
For more information, see Background File Transfers Overview for Windows Phone
The first thing you need to understand is page navigation. If you are navigating from a page to another page (and not changing visibilitiea of controls) then as soon as you navigate your old page page is unloaded and null. If you have a global in your page that you navigated from then that's also null. So you have to put your downloading webclient or whatever at an application global level. Do all your downloading in App.xaml.cs or better yet create your own shared class among all pages.
Now when the application exists the App.xaml.cs Unloaded gets called. So before you unload the app you need to store the already downloaded portion in IsolatedStorage and when the app.xaml.cs gets relaunched in the loaded event handler you need to check to see if the user was downloading something in the isolated storage then complete the download.
Related
This is going to be a bit vague but I have a setup where a web application has 2 entry points - one from parent path and other from a different application. If the user came from the parent path and uses search button it opens up a new tab without any issues. However if user accessed the web application from the external entry point and then used the search function the new tab would open but would close itself after ~3 seconds. The search tab is opened via 'windows.open({url})'command. I don't have ability to debug the backend as it's using vendor war file without source files, so I'm mainly looking for ideas what could cause such behavior. Its not browser specific.
I've been working on a browser extension allowing users to generate epub files from any webpage.
To use the extension, a user has to click on a toolbar button which opens a popup. On the latter, after specifying a config, the user clicks on "Generate". Here is my issue though:
When I use the download API directly, and specify saveAs to false (i.e the user is NOT prompted where to save the file), then the download is completed as expected and the file saved in some location.
However, when I do set saveAs to true --- which is what I want in the final version --- then once the user has selected the location under which to save the file, the download fails. My intuition is that as soon as the file location window pops up, the popup looses focus and dies, which makes the download impossible to resume.
Is that the explanation? And is there a way to prevent such a problem? I do not find my use case to be much of a stretch, and do not get why popups associated with browser actions are not allowed to loose focus for file selection.
Another weird thing is that I'm pretty confident this problem only appeared recently in firefox, since when I started developing the extension, I had no issue.
My intuition is that as soon as the file location window pops up, the
popup looses focus and dies, which makes the download impossible to
resume.
That's right...
Browser Action Popup is page and once page is closed, async operations will lose their reference. It is best to pass async operations to the background script.
You can use
runtime.sendMessage()
to pass a message to the background script to run the download.
You can also use the async
runtime.getBackgroundPage() to run a function in the background script but the first option works
easier as you dont need to wait for the async response as in runtime.getBackgroundPage()
My application downloads a PDF and stores it in the LocalState folder for my Windows 8 app.
I have a link within the app that I would like to show the PDF when the user clicks it.
I've tried displaying it using ms-appdata:///local/pdfs/filename.pdf in a window.open call and I also tried using the InAppBrowser plugin within cordova with no luck. Additionally, I've tried the following:
var uri = new Windows.Foundation.Uri('ms-appdata:///local/pdfs/filename.pdf');
var file = Windows.Storage.StorageFile.getFileFromApplicationUriAsync(uri);
Windows.System.Launcher.launchFileAsync(file).done();
I know the file exists as I'm getting a file result back. Just not sure how to allow the user to view it.
By design, the local appdata folder on Windows is accessible only to that app, or to full-trust desktop applications (and this is probably true of similar sandboxed locations on other platforms). As a result, a Windows Store app that gets launched with Launcher.launchFileAsync won't be able access that location (nor can a webview process, which is also sandboxed). If a desktop application gets launched, on the other hand, it probably can access the file, but you can't tell ahead of time if that's the case. Bottom line is that local appdata isn't a good location for letting other apps get at the file.
You'll need to save the file in another location that is accessible to other apps. There are two approaches here, both of which will require a little user interaction to select a location, so they can place the PDFs anywhere they want:
Have the user select a save folder for your app, which they can do once. You would invoke the FolderPicker for this purpose, and save the selected folder in the FutureAccessList. This way you can have the user select the save folder, which grants you consent to save there, and by saving it in the FutureAccessList you can retrieve it in subsequent sessions without having to ask the user again. Refer to the File Picker Sample and the File Access Sample for more.
Have the user select a save location for each individual file, using the FilePicker (see the same sample), and you can also use the access cache to save permissions to those individual locations if you need them later.
There might be Cordova plugins that work with these APIs too, but I haven't checked. Either way, once the file is in an accessible location, launching the file should work just fine.
As an alternate solution, you could consider rendering the PDFs directly in your app. Windows has an API for this in Windows.Data.Pdf, with an associated sample. There might be a plugin or other JS libraries that could also work for this.
I'm trying to delete files inside application folder from my Cocoa application. By enabling Sandbox mode, I'm not able to delete files inside application folder.
This Sandbox mode has some option for enabling Read/Write access to downloads, pictures, movies, music and user selected file.
Before that I enabled Read and Write Access for user selected file and done my deletion using NSOpenPanel. It works fine and deletes files inside application folder but it opens panel every time when I run my app. Here I dont want any user interaction/permission to delete files inside application folder. Is there any solution to delete files with above defined constraints.
You need to use Security-Scoped Bookmarks:
Your app’s access to file-system locations outside of its container—as granted to your app by way of user intent, such as through Powerbox—does not automatically persist across app launches or system restarts. When your app reopens, you have to start over. (The one exception to this is for files open at the time that your app terminates, which remain in your sandbox thanks to the OS X Resume feature).
So I have a website running that displays full path of a TFS File on the page somewhere, I want the user to be able to click on it, which should then open up that file from TFS inside their Visual Studio.
The command to do this inside Visual Studio is "File.TfsOpenFromSourceControl" (DTE command) - it's basically the user manually going to that file using the Source control explorer and double clicking to open it up.
I am wanting to simulate that action from my web app inside the browser.
Update: The Web app is a pure ASPNet MVC app with Jquery available to it. I am already showing the file's content to the user in the web app. But I want the user to open the same file in Visual studio, by clicking on the file path in the web app. The question is more of Browser to VS integration and how to execute the DTE command in question, from within the web app context of the browser.
Any clues would be helpful
I don't know the answer to Pavel's question, so I'll sketch an outline of both solutions.
If you want to display the file inside the browser, call the Item.DownloadFile() API. NB: in 2008 SP1 there is another overload of this method that allows streaming into a memory buffer instead of writing directly to the filesystem. If you don't already work with Item objects directly, you can retrieve them via the GetItem() / GetItems() APIs.
If you want to make the file open in VS, there are a couple approaches. Perhaps your web app already includes the concept of local workspace(s) for the user, similar to Source Control Explorer. If so, you'd simply call Workspace.GetLocalItemForServerItem() to find the local path of the item, then ShellExecute it. (Or maybe pass it as a command line parameter to devenv.exe, if it's not natively associated with VS.) If not, you can either create a temporary workspace on behalf of the user, or use the same DownloadFile() API shown before; stream the contents to the client over a web service, save to disk, then launch VS as before.
Naturally, the more involved scenarios under option #2 will require deeper OS integration than the DOM / Javascript can provide. Would help to know if this web app is already built on ActiveX, Flash, Silverlight, XBAP, or similar technology...