Imagine you have a large number of video files stored on a server, and a Flex app which lets users play those videos they have access to. How can you best set this up? Wouldn't the Flex app just be sent the name of the video to play... in which case couldn't someone else write another flex app if they knew the file names? Can Flex play videos hosted on other sites? Is there some clever piece on the server I'm missing, which sits between the Flex video player and the files?
Ask users to log-in with a username and password - you can use OpenID if you want.
Update:
Set the crossdomain.xml of your server in such a way that only Flash movies from your domain can access content from there.
You can write a server-side script (in PHP or something else) that serves the file only if your user is allowed to see it (how to determine that you'll have to come up with yourself). This is a bit of a performance hit, although not so much if you use PHP's readfile().
Can Flex play videos hosted on other sites?
Your crossdomain.xml can control this. e.g. myvideoserver.com/crossdomain.xml would contain entries based on who you want to grant access to, like myflexserver.com. Then just ripping off your main flex application wouldn't give them access to your video files.
Related
supppose I use html5 local storage for my website.
1)can End user see my local storage values through browser using view source code etc?
2)How can we enter data for HTML5 local storage as domain level, i dont want to add my records manually when page loads everytime?
3where will HTML5 local storage content be saved?
I)in client side?
II)in server side(webserver)
anyhelp please?
Not through view source, but many Developer Tools support this. So yes, a user could very easy figure out what the contents of their browser's localStorage is. For example, in Chrome, open the Developer Tools, and on the Resources tab select "Local Storage"
I think what you are asking for is "How to I add local storage without writing the code in every page". You would typically then put that code in a common .js file - and reference it whenever you needed it. If you need it in every page, then depending on which platform you are using, they probably have some sort of "master". ASP.NET WebForms has Master Pages, ASP.NET MVC has ViewStart, etc.
Client side. It's local storage - as in it is local to the browser.
As the title says, how would I go about doing this? I want to check a value stored in a file.
This is impossible and has nothing to do with ASP .NET. The browser is responsible for rendering the page to the client, and browsers, for obvious reasons (security), don't have access to the user's file system. The only thing a browser can do, is read cookies (essentially text files) sent to the user from the same domain the website belongs to.
HTML5 has a new feature called local storage but you still won't be able to access ANY file on the user's computer.
Using Javascript with ASP.Net applications can work quite well, I've done it for a couple of sites I've done. If you just want to run some code on the client when a checkbox is ticked for instance, try this...
replace the myFunction() portion out with whatever client side code you want to write.
If you unfamiliar with Javascript as a language, check this out... http://www.w3schools.com/js/default.asp
You can do that using ActiveX control or SilverLight
Some are saying it's not possible, and that is true for the Internet. However, I have done this before on an Intranet system. The server knew the users computer name and could access a local configuration file, no ActiveX, no Silverlight.
I made a blog widget in flex. I need manipulate cookie in my widget which is added to my user's blog. But under some circumstance, some blog hosts forbid accessing to javascript, so i can not access cookie in flex by externalInterface. Does anyone know how to access cookie in this context? thanks.
You need to set allowScriptAccess to "*" in your embed code. Unfortunately, you cannot allow access on a per domain basis, so it's all or nothing. However, the owner of the blog might not want to grant this privilege, in which case you just cannot count on having access to Javascript from your swf.
PS: If you are allowed to serve a swf from the same domain with granted access to Javascript, you might be able to use it as proxy for sending the data retrieved with javascript to the swf served from the other domain. Not sure if this is the best idea, though.
My answer is, you can't access browser cookies from the Flash Player. The ExternalInterface usage is kind of a hack.
Based on the error, it sounds like your SWF is being served from a different domain than the web page that contains it. Is that true? If so, that is the cause of the error. Isn't that the same sort of approach that "Cross Site Scripting" exploits use?
You can allow JavaScript to access it's HTML wrapper from a different domain by specifying the allowScriptAccess to always in the SWF embed code. More info in the Adobe docs.
You can try adding a crossdomain.xml file to the main site, although I did not think that would have an effect because I'm pretty sure that ExternalInterface usage is not a crossdomain.xml checking case.
I'm curious as to where the cookie is coming from. If your Flex application is creating the cookie via a SharedObject then you don't need javascript to access it. If the cookie is coming from another application/source then to my knowledge, the only real way to access it is via the javascript externalinterface method.
Is there a way to programmatically set the name of a file to be uploaded from a web page? I suspect that browser security restrictions make this impossible, but I'm hoping someone will prove me wrong.
I have a web application that needs to let the administrator upload HTML. The admin selects the HTML file, then the app uploads that file, plus figures out all the supporting files (images, stylesheet, etc) and uploads them too. There doesn't seem to be a way to programmatically upload the supporting files from a web page, since the user has to specify each file explicitly.
Currently I have a separate Windows app to do this, but it would be ideal to have this functionality integrated with the rest of the app. My back end is ASP.NET with C#.
There is no way to programatically grab files from a user's computer via the browser. This would be a security violation if a website could just grab things.
Yes you can (in modern browsers)...
You can get and set the value of HTMLInputElement.files.
See this answer.
No, you cannot do this without a client-side application or special plug-in.
Browser security doesn't allow the server to obtain information about the hard drive contents of the client.
You may be able to do this using some form of browser plug-in. This is more work for you (and there are potential security implications for this beyond those found when you just have users run your app). However, it may prevent a more integrated experience for your users. I'd hesitate to eliminate the application completely, though. Browser compatibility issues are common.
Let's say we have a web site with a CF app that was written in-house.
Assume that:
Server 2003 IIS6 or 2008 IIS7 will be used
ColdFusion 8 will be used
Directory browsing is denied
SSL is required to connect
The account login process is secure (yeah I know that is a whole other
ball of wax but that concept is discussed ad nauseum on the web).
Say I have a file at https://domain.com/folder1/folder2/ with a name like picture92352.ext imagine it as a jpg or pdf or whatever. The entire path between the domain name and the file varies widely in naming structure, depth, etc. Files are not all lumped together in one folder.
The app restricts links by user such that a user would have to have access to that file to find it in the first place but as it stands now if a person knew the full URL to that file they could retrieve it without logging in to the app. It's the classic security by obscurity situation. A random person isn't likely to find a file they shouldn't get to but once someone is given access they know how to access it from another PC where their actions might not be traced back to them.
How do I restrict access to these files before someone logs in and still make them accessible to outside users after they log in? Is there a way to do it with permissions only or is the only answer to have code dynamically moving files around at the time of the request or is there some obvious step I'm not even thinking of?
Let me clarify this slightly. No matter how the file is presented on a page a user can use the browser IE, Firefox, etc to examine the URL the file comes from. If the image is a link there is always copy shortcut in the right click menu for IE and the same functionality in FF is called copy link location. If the image is displayed inline as part of the page an IE user can right click and choose properties to see the URL, in FF the same functionality is present to see properties but there is an even quicker more convenient option labeled copy image location. Once a user knows the URL to a file if the location or file name doesn't change they can use that URL without authenticating in the CF app.
If I change the NTFS/share permissions so that IUSR can't see the content then my CF app and IIS can't push it. What strategy do I use to provide the file in the CF app that doesn't leave this hole open?
You could write a CFM page that serves up the images. Then you just make sure they are authenticated inside the CFM.
<!-- something like this -->
http://localhost/GetFile.cfm?file=foobar.jpg
In GetFile.cfm, you would do something like:
<!-- the filename part is what the browser will pre-popualate the file name in the download dialog as -->
<CFHEADER name="Content-disposition" value="attachment;filename=picture92352.ext">
<CFCONTENT type="text/plain" file="\\fileserver\folder1\folder2\picture92352.ext">
Take a look at the various MIME types.
If you wanted to do something similar but keep a more natural URL, I think you would need to leverage the Java servlet underpinnings of ColdFusion to create a handler for any URL matching a certain pattern.