can we see html localstorage content through client browser? - asp.net

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.

Related

HTML5 Local Storage data not reflected across active tabs/windows in IE 11

We have created a functionality where in we provide users to works with forms in an Offline Mode.
We are using HTML 5 Local Storage to store all the offline data.
All the forms have their own html files (for example:form-1.html,form-2.html.)
We have a parent html page which makes use of an iframe to load the requried html file based on the form selected from the drop down list.
After the user have made the modification in offline mode,the user can sync in their changes by logging to the ASP.Net WebSite.
The problem ,we are facing is that the copy of Local Storage that in modified by the user in the offline mode is not in sync when the user their to sync the changes to ASP.Net Website.
In short,when we examine the Local Storage in the IE console of the browser when we login to ASP.Net Website,it does not reflect the changes made to the Local Storage during the offline mode.
Both parent html page and the ASP.Net Website page is serverd from the same domain.
I came across this piece of article which says that this is an on going issue and it has not been fixed in IE 11.
IE and Local Storage Issues
Please see bullet# 3.
Has any one had the same kind of experience.?
Any work around?
I tested many ideas, for me attaching an empty event handler for onstorage property worked!
The WindowEventHandlers.onstorage property contains an event handler that runs when the storage event fires. This occurs when a storage area is changed (e.g. a new item is stored.)
here is my code
window.onstorage = function(e){};
Microsoft is well aware of the issue, but after about 3 years , there is still no fix and probably it will never be. more info here
This is a known bug: https://connect.microsoft.com/IE/feedback/details/812563/ie-11-local-storage-synchronization-issues
There is a workaround added to the bug report that you can use indexedDB, which is synchronized among frames. But before you can create a DB, the user need to give your web app permission to create a database.

Is there any way to run code on the client in ASP.NET?

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.

Programmatically set name of file to upload in webpage

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.

How to control which users can see which videos

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.

How would you allow users to edit attachments in a web application?

We have created a web application, using ASP.NET, that allows users to upload documents and attach them to business entities, like customers, contacts and so on.
The application runs on the intranet and all files are uploaded through the web application into a shared folder on the server.
I would like, right from the web page, for the user to open the actual file, edit it and then save the changes back to the original location. This is a piece of cake in a Windows environment, I'm just wondering what, if any, is the best way to handle this in a web environment?
The files are usually Word documents, Excel documents and images.
Clarification
We would display all the attachments in a list format. We would like it so that the user would click on an edit link and the file would be opened in the appropriate application, for example, Microsoft Word or Microsoft Excel. I think the file associations in Windows would already handle this. We are just trying to save our user the time to download the original file, make their changes, delete the old file, and the upload the new file.
SharePoint does this by exposing FrontPage extensions which Word and Excel know how to deal with.
If you want to look at a commercial product for ASP.NET that allows you to edit images with AJAX (no need for installed software), I work for a company that has one (Atalasoft)
WebDAV is probably what you want. (Free)
If all your client computers are Windows, map a shared folder on the server to the same drive letter on every client and use the file:// format.
Let's say you share \ServerName\ShareName to H: on every client's computer, the you can make the link as file://h:\pat_to_the_file_under_your_share\fileName.doc
If not every one of the client's computers are in Windows, then you might try to make your links as follows (not sure if ot works):
file://\ServerName\ShareName\pat_to_the_file_under_your_share\fileName.doc
I'm trying to do something with using file:// instead of http:// but it's real sporadic based on the browser. Seems to work fine in IE, okay in Firefox, and goes nowhere in Chrome.
Looks like I may just be stuck with downloading, editing, and re-uploading the document.
It sounds like you want something similar t eRoom, where the browser works in conjunction with a component that intercepts a stream from http, stores it in a temp folder, then fires up Word or Excel and allows you to edit the stream.
You may have to create a component that will intervene and create a temporary local copy of the file.
This tool should do what you need.
http://www.dlitools.com/dlitools/dlitoolsHome.nsf/0FA6B8B31F831F468525736B0001C606/4BBD7E8684EA8DB78525754E006C63A3?OpenDocument

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