Develop Reference

Create an extension to the browser to acces local scanner

I would like to access a special hardware (a penta scanner, for the wisest ;) ) from a web page.
The aim is to retrieve the information from the scanner and compute it on server side.
The problem here, is that I have to summon functions from a DLL that has to be on the client side. I have two leads for that:
Develop a COM DLL and use ActiveX
Try to get through a homemade extension for a web browser in order to communicate with the local DLLs.
I've tried the first option, and I got stuck and I've posted another thread about it. Anyway, even if it works, there are too many constraints about it (as to use IE or the fact that even Microsoft is not fond of this feature and banned it from edge).
The second method is something that I found on another forum but, I do not understand how I can interact with a browser extension (whatever the browser).
So what I am asking is:
Is it possible to use a web browser extension as a medium to a local DLL and if so, would you be so kind as to give a hint about how to do ar anything that might look like a start about how to do it (even just some key words to use on google, since mine didn't get anything)....
Thanks.

Based on my understanding, the motive to develop an Extensions is to enhance the feature and functionality for particular web browser.
You cannot control any hardware devices like printer or scanner with it.
So if your goal is to control the scanner from your web page with the help of any kind of extension than I think you cannot do this with Extension.

Allow access to weblink only via native iOS and Android apps

I have website link at which I have designed a html/javascript web app. I used iOS and Android app to create an app that encapsulates the web app.
Is there a way to block access to the website link and only allow access to the website link only thru the native apps calling the link.
In short safari, IE, Chrome must not be able to access the link, but the iPhone & Android app should be able to access it.
Is there some way to tell that the app is accessing the site and not the phone or pc browsers.
I am sure there a number of ways to implement this.
Thanks,

It depends on how is the web app implemented. Since native Web Views are pretty much the wrapper for the standard browser (Safari/Chrome), you will find it tough to filter it based on that.
What you can do, however, is to add an extra GET variable (for ex. &ref=youruniquecodehere) or a custom User-Agent, based on which you will be able to identify, whether your application authorized the request (with a proper access code) or if it's a generic request using browser.
However, both of these options can still be bypassed if researched, although it'd require slightly more time. Not sure whether a solution that would work in 100% of cases exists.
Hope that helps, please correct me if I'm wrong.

Is there a way to distinguish that my Javascript is running in a trident-based application vs. Internet Explorer?

I've got a third party script that runs in many places on the web. I'd like to be able to tell when I'm running in an app vs. a browser. The user agent doesn't always help. Chrome provides the chrome object which has some different properties depending on the environment. Anyone know of anything similar for IE?
This is for a product similar to google analytics which can be implemented or wind up in many environments, and I'm trying to distinguish them better.

Check for window.external. If window.external is null then the web page is loaded into a Web Component, otherwise it is loaded via browser.
window.external enable you to communicate with [ComVisible(true)] instances which are enabled by default in the browsers. As long as your apps are not decorated with [ComVisible(true)], you can distinguish between app and browser page consumption.
Read more about window.external on http://msdn.microsoft.com/en-us/library/ie/ms535246%28v=vs.85%29.aspx

The way Google Analytics checks for browser and device is the HTTP User-Agent header. It lets you check for browser, browser version, OS, OS version, and sometimes device:
http://jonathanstark.com/blog/windows-phone-8-user-agent-string
http://msdn.microsoft.com/en-us/library/ms537503(v=vs.85).aspx
You can parse this string in Javascript as well:
Getting the User Agent with JavaScript

Any Javascript functions to get homepage ,search provider ,favourites etc from browsers like Firefox and google chrome

my application is setting browserhome page ,search provider ,favourites etc to all supported browsers like googlechrome,firefox,internet explorer.My purpose is to automate my application using selenium .In case of IE these informationa are stored in registry . so it is easy for me to validate the above details .But for firefox and google chrome its bit problem .So i just want know whether there is any functions available in javascript to check browser homepage ,search provider,favourites etc in firefox and google chrome ?

The simple answer is no. It would be a security and privacy issue if client side js code could access that information. Instead you would need to use a browser extension, or in your case you can just use an external program with administrative rights. I am pretty sure that selenium does not have this functionality built in, however it is all available if you know where the browser stores it. IE uses the registry, but chrome and Firefox use proprietary files in their profile directories. There may be an library that does this, otherwise it is possible

Is accessing USB from a web application for cross browser cross OS possible at all?

I am wondering if there is a way we can achieve this. I heard different things about Silverlight 4, JavaScript or ActiveX control, but I have not seen any demo of code for any of them.
Is there a web component that is available or how can I write one?
We really like to capture a client's USB drive via the Web and read/write data on it. This has to work for any operating system in any web browser.
What about WPF in browser mode? I read that I can host my WPF applications inside browser and sort of like smart client.
Here is a great example of doing this via Silverlight 4, but the author mentions about possibility of accessing USB on Mac via:
Enable executing AppleScript scripts.
This option will let us have the same amount of control on a Mac machine as we do on a Windows machine.
Add an overload to ComAutomationFactory.CreateObject() that calls the “Tell Application” command under the scenes and gets a AppleScript object.
This option would work extremely well for Microsoft Office automation. For any other operating system feature, you’ll have to code the OS access twice.
I did not quite understand it. Has any tried this?

Web browsers are deliberately isolated from the filesystem for security reasons. Only Java (not "Java Script"), Flash or browser plug-ins can accomplish this.

JavaScript cannot directly access your local disk (including a flash drive) for security reasons (would you really want any web site you look at to access, change, or even delete your files?), and ActiveX controls are IE-specific, so you should probably use a Java applet (not JavaScript). While Java's security policy normally does not allow access to local disks, signed applets can with the user's permission.

If you're willing to introduce a dependency on Flash (10), you can use the FileReference class to get access to one file at a time, first for reading using the browse method, then for writing using the save method.
Note that for security reasons, each call to these methods must be triggered as a result of user input (e.g. clicking a button), and each time they are called an OS-specific File Open/Save As dialog box is displayed.
There's a video tutorial which gives some sample code for editing a text file (load + save) directly in Flash, without needing any server-side help. It should be enough to get you started in the right direction.

What about WPF in browser mode...I read that I can host my wpf apps inside browser and sort of like smart client.