Custom protocol handler in chrome

Question

How do i set up a custom protocol handler in chrome? Something like:

myprotocol://testfile

I would need this to send a request to http://example.com?query=testfile, then send the httpresponse to my extension.

Answer 1

The following method registers an application to a URI Scheme. So, you can use mycustproto: in your HTML code to trigger a local application. It works on a Google Chrome Version 51.0.2704.79 m (64-bit).

I mainly used this method for printing document silently without the print dialog popping up. The result is pretty good and is a seamless solution to integrate the external application with the browser.

HTML code (simple):

<a href="mycustproto:Hello World">Click Me</a> 

HTML code (alternative):

<input id="DealerName" /> <button id="PrintBtn"></button>  $('#PrintBtn').on('click', function(event){   event.preventDefault();   window.location.href = 'mycustproto:dealer ' + $('#DealerName').val(); }); 

URI Scheme will look like this:

You can create the URI Scheme manually in registry, or run the "mycustproto.reg" file (see below).

HKEY_CURRENT_USER\Software\Classes    mycustproto       (Default) = "URL:MyCustProto Protocol"       URL Protocol = ""       DefaultIcon          (Default) = "myprogram.exe,1"       shell          open             command                (Default) = "C:\Program Files\MyProgram\myprogram.exe" "%1" 

mycustproto.reg example:

Windows Registry Editor Version 5.00  [HKEY_CURRENT_USER\Software\Classes\mycustproto] "URL Protocol"="\"\"" @="\"URL:MyCustProto Protocol\""  [HKEY_CURRENT_USER\Software\Classes\mycustproto\DefaultIcon] @="\"mycustproto.exe,1\""  [HKEY_CURRENT_USER\Software\Classes\mycustproto\shell]  [HKEY_CURRENT_USER\Software\Classes\mycustproto\shell\open]  [HKEY_CURRENT_USER\Software\Classes\mycustproto\shell\open\command] @="\"C:\\Program Files\\MyProgram\\myprogram.exe\" \"%1\"" 

C# console application - myprogram.exe:

using System; using System.Collections.Generic; using System.Text;  namespace myprogram {   class Program   {     static string ProcessInput(string s)     {        // TODO Verify and validate the input         // string as appropriate for your application.        return s;     }      static void Main(string[] args)     {       Console.WriteLine("Raw command-line: \n\t" + Environment.CommandLine);       Console.WriteLine("\n\nArguments:\n");        foreach (string s in args)       {         Console.WriteLine("\t" + ProcessInput(s));       }        Console.WriteLine("\nPress any key to continue...");       Console.ReadKey();     }   } } 

Try to run the program first to make sure the program has been placed in the correct path:

cmd> "C:\Program Files\MyProgram\myprogram.exe" "mycustproto:Hello World" 

Click the link on your HTML page:

You will see a warning window popup for the first time.

To reset the external protocol handler setting in Chrome:

If you have ever accepted the custom protocol in Chrome and would like to reset the setting, do this (currently, there is no UI in Chrome to change the setting):

Edit "Local State" this file under this path:

C:\Users\Username\AppData\Local\Google\Chrome\User Data\ 

or Simply go to:

%USERPROFILE%\AppData\Local\Google\Chrome\User Data\ 

Then, search for this string: protocol_handler

You will see the custom protocol from there.

Note: Please close your Google Chrome before editing the file. Otherwise, the change you have made will be overwritten by Chrome.

Reference:

https://msdn.microsoft.com/en-us/library/aa767914(v=vs.85).aspx

Answer 2

Chrome 13 now supports the navigator.registerProtocolHandler API. For example,

navigator.registerProtocolHandler(     'web+custom', 'http://example.com/rph?q=%s', 'My App'); 

Note that your protocol name has to start with web+, with a few exceptions for common ones (like mailto, etc). For more details, see: http://updates.html5rocks.com/2011/06/Registering-a-custom-protocol-handler