simplest cross-browser check if protocol handler is registered

When user clicks link with custom protocol (like myapp://superlink)

I need either launch an app or allow user to download and run configuration app

I am looking for cross-browser way to check if custom protocol is registered

I've tried to determine this by checking user agent server-side (for IE)

[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Internet Settings\5.0\User Agent\Post Platform] "myapp"=""

sends

`....NET CLR 3.0.30729; .NET4.0C; .NET4.0E; InfoPath.3; **myapp**`

as user-agent

This is good, clean way, easy configuration:

just download .reg file and run it or propagiate via ms windows policy

I can't fix this for Chrome and Firefox

Are there any client-side solution (in js)?

My enviroment: IE8+, Chrome (latest), Firefox(latest)

There is this old tricks that it always never fails me.

The core functionality that you need is setTimeout. I will tell you in detail:

setTimeout(function() {
  window.location = "http://itunes.com/app/yourapplocation";
}, 200);

// once you do the custom-uri, it should properly execute the handler, otherwise, the settimeout that you set before will kick in
window.location = "myapp://superlink";

Now you mentioned that it maybe a link or links so I made this nice function just for your convenience:

HTML code

<a href="myapp://superlink" data-href-alt="http://itunes.com/app/yourapplocation">Click here</a>

JS code

$("a[href*='myapp://']").click(function(e)
{
  var el = $(this);
  setTimeout(function() {
    window.location = el.data("data-href-alt");
  }, 200);

  // once you do the custom-uri, it should properly execute the handler, otherwise, the settimeout that you set before will kick in
  window.location = el.data("href");

  e.preventDefault();
});

Hope this will help you :)

I had a similar problem where I needed to check whether a custom protocol is already registered (which will open an executable file), or otherwise open a download page or do something else. Unfortunately there is no easy way to deal with this since every browser behaves differently. I tried to collect all information and come up with a rather generic library for this matter, you can take a look at:

https://github.com/ismailhabib/custom-protocol-detection

ps: the solution for non Windows 8 IE is rather ugly, but I couldn't find a better solution.

kororo's solution wouldn't work for me for some reason, so I managed with this slightly modified solution instead.

<html>
<a id="link">Click Me</a>
<script>
var link = document.getElementById('link');
var timeout;
window.addEventListener('blur',function(e){
    window.clearTimeout(timeout);
})

link.addEventListener('click', function(e) { 

    timeout = window.setTimeout(function() {
      console.log('timeout');
      window.location = "https://myapp.net";
    }, 1000);

    window.location = "myapp://";
    e.preventDefault();
});
</script>
</html>

Update to Korono's answer, this worked for me:

$(function() {
    var timeIndex;
    $("a[href*='myapp://']").blur(function(e)
    {
        clearTimeout(timeIndex);
    });

    $("a[href*='myapp://']").click(function(e)
    {
      var el = $(this);
      timeIndex = setTimeout(function() {
        window.location = el.attr("data-href-alt");
      }, 200);

      // once you do the custom-uri, it should properly execute the handler, otherwise, the settimeout that you set before will kick in
      window.location = el.attr("href");
      e.preventDefault();
    });
});

Salaam

Install ismailhabib/custom-protocol-detection

By including this JS file protocolcheck.js

Then write code something like this

<div id="protocol" href="myprotocol:johndoe@somewhere.com">Check Protocol</div>

<script>
        $("#protocol").click(function (event) {
            protocolCheck($(this).attr("href"), function () {
                    alert("protocol not recognized");
                });
            event.preventDefault ? event.preventDefault() : event.returnValue = false;
        });
</script>

来源：https://stackoverflow.com/questions/24779312/simplest-cross-browser-check-if-protocol-handler-is-registered

标签

javascript

protocol-handler