How to check if an app is installed from a web-pag

问题:

I want to create a web-page, a page that will redirect an iPhone to the app-store if the iPhone does not have the application installed, but if the iPhone has the app installed I want it to open the application.

I have already implemented a custom url in the iPhone application so I have an url for the application that is something like:

myapp://

And if this url is invalid, I want the page to redirect to the app store. Is this possible at all?

If I don\'t have the application installed on the phone and write the myapp:// url in safari, all I get is an error message.

Even if there exists an ugly hack with javascript I would really like to know?

回答1:

As far as I know you can not, from a browser, check if an app is installed or not.

But you can try redirecting the phone to the app, and if nothing happens redirect the phone to a specified page, like this:

setTimeout(function () { window.location = \"https://itunes.apple.com/appdir\"; }, 25);
window.location = \"appname://\";

If the second line of code gives a result then the first row is never executed.

Hope this helps!

Similar question:

• iPhone browser: Checking if iPhone app is installed from browser
• Is it possible to register a http+domain-based URL Scheme for iPhone apps, like YouTube and Maps?

回答2:

To further the accepted answer, you sometimes need to add extra code to handle people returning the browser after launching the app- that setTimeout function will run whenever they do. So, I do something like this:

var now = new Date().valueOf();
setTimeout(function () {
    if (new Date().valueOf() - now > 100) return;
    window.location = \"https://itunes.apple.com/appdir\";
}, 25);
window.location = \"appname://\";

That way, if there has been a freeze in code execution (i.e., app switching), it won\'t run.

回答3:

iOS Safari has a feature that allows you to add a \"smart\" banner to your webpage that will link either to your app, if it is installed, or to the App Store.

You do this by adding a meta tag to the page. You can even specify a detailed app URL if you want the app to do something special when it loads.

Details are at Apple\'s Promoting Apps with Smart App Banners page.

The mechanism has the advantages of being easy and presenting a standardized banner. The downside is that you don\'t have much control over the look or location. Also, all bets are off if the page is viewed in a browser other than Safari.

回答4:

You can check out this plugin that tries to solve the problem. It is based on the same approach as described by missemisa and Alastair etc, but uses a hidden iframe instead.

https://github.com/hampusohlsson/browser-deeplink

回答5:

@Alistair pointed out in this answer that sometimes users will return to the browser after opening the app. A commenter to that answer indicated that the times values used had to be changed depending on iOS version. When our team had to deal with this, we found that the time values for the initial timeout and telling whether we had returned to the browser had to be tuned, and often didn\'t work for all users and devices.

Rather than using an arbitrary time difference threshold to determine whether we had returned to the browser, it made sense to detect the \"pagehide\" and \"pageshow\" events.

I developed the following web page to help diagnose what was going on. It adds HTML diagnostics as the events unfold, mainly because using techniques like console logging, alerts, or Web Inspector, jsfiddle.net etc all had their drawbacks in this work flow. Rather than using a time threshold, the Javascript counts the number of \"pagehide\" and \"pageshow\" events to see whether they have occurred. And I found that the most robust strategy was to use an initial timeout of 1000 (rather than the 25, 50, or 100 reported/suggested by others).

This can be served on a local server, e.g. python -m SimpleHTTPServer and viewed on iOS Safari.

To play with it, press either the \"Open an installed app\" or \"App not installed\" links. These links should cause respectively the Maps app or the App Store to open. You can then return to Safari to see the sequence and timing of the events.

(Note: this will work for Safari only. For other browsers (like Chrome) you\'d have to install handlers for the pagehide/show-equivalent events).

Update: As @Mikko has pointed out in the comments, the pageshow/pagehide events we are using are apparently no longer supported in iOS8.

<html>
<head>
</head>
<body>
<a href=\"maps://\" onclick=\"clickHandler()\">Open an installed app</a>
<br/><br/>
<a href=\"xmapsx://\" onclick=\"clickHandler()\">App not installed</a>
<br/>

<script>

var hideShowCount = 0 ;
window.addEventListener(\"pagehide\", function() {
    hideShowCount++ ;
    showEventTime(\'pagehide\') ;
});

window.addEventListener(\"pageshow\", function() {
    hideShowCount++ ;
    showEventTime(\'pageshow\') ;
});

function clickHandler(){
    var hideShowCountAtClick = hideShowCount ;
    showEventTime(\'click\') ;
    setTimeout(function () {
               showEventTime(\'timeout function \'+(hideShowCount-hideShowCountAtClick)+\' hide/show events\') ;
               if (hideShowCount == hideShowCountAtClick){
                    // app is not installed, go to App Store
                    window.location = \'http://itunes.apple.com/app\' ;
               }
            }, 1000);
}

function currentTime()
{
    return Date.now()/1000 ;
}

function showEventTime(event){
    var time = currentTime() ;
    document.body.appendChild(document.createElement(\'br\'));
    document.body.appendChild(document.createTextNode(time+\' \'+event));
}
</script>
</body>
</html>

回答6:

As of 2017, it seems there\'s no reliable way to detect an app is installed, and the redirection trick won\'t work everywhere.

For those like me who needs to deep link directly from emails (quite common), it is worth noting the following:

• Sending emails with appScheme:// won\'t work fine because the links will be filtered in Gmail

• Redirecting automatically to appScheme:// is blocked by Chrome: I suspect Chrome requires the redirection to be synchronous to an user interaction (like a click)

• You can now deep link without appScheme:// and it\'s better but it requires a modern platform and additional setup. Android iOS

---

It is worth noting that other people already thought about this in depth. If you look at how Slack implements his \"magic link\" feature, you can notice that:

• It sends an email with a regular http link (ok with Gmail)
• The web page have a big button that links to appScheme:// (ok with Chrome)

回答7:

I need to do something like this I ended up going with the following solution.

I have a specific website URL that will open a page with two buttons

1) Button One go to website

2) Button Two go to application (iphone / android phone / tablet) you can fall back to a default location from here if the app is not installed (like another url or an app store)

3) cookie to remember users choice

<head>
<title>Mobile Router Example </title>


<script type=\"text/javascript\">
    function set_cookie(name,value)
    {
       // js code to write cookie
    }
    function read_cookie(name) {
       // jsCode to read cookie
    }

    function goToApp(appLocation) {
        setTimeout(function() {
            window.location = appLocation;
              //this is a fallback if the app is not installed. Could direct to an app store or a website telling user how to get app


        }, 25);
        window.location = \"custom-uri://AppShouldListenForThis\";
    }

    function goToWeb(webLocation) {
        window.location = webLocation;
    }

    if (readCookie(\'appLinkIgnoreWeb\') == \'true\' ) {
        goToWeb(\'http://somewebsite\');

    }
    else if (readCookie(\'appLinkIgnoreApp\') == \'true\') {
        goToApp(\'http://fallbackLocation\');
    }



</script>
</head>
<body>


<div class=\"iphone_table_padding\">
<table border=\"0\" cellspacing=\"0\" cellpadding=\"0\" style=\"width:100%;\">
    <tr>
        <td class=\"iphone_table_leftRight\">&nbsp;</td>
        <td>
            <!-- INTRO -->
            <span class=\"iphone_copy_intro\">Check out our new app or go to website</span>
        </td>
        <td class=\"iphone_table_leftRight\">&nbsp;</td>
    </tr>
    <tr>
        <td class=\"iphone_table_leftRight\">&nbsp;</td>
        <td>
            <div class=\"iphone_btn_padding\">

                <!-- GET IPHONE APP BTN -->
                <table border=\"0\" cellspacing=\"0\" cellpadding=\"0\" class=\"iphone_btn\" onclick=\"set_cookie(\'appLinkIgnoreApp\',document.getElementById(\'chkDontShow\').checked);goToApp(\'http://getappfallback\')\">
                    <tr>
                        <td class=\"iphone_btn_on_left\">&nbsp;</td>
                        <td class=\"iphone_btn_on_mid\">
                            <span class=\"iphone_copy_btn\">
                                Get The Mobile Applications
                            </span>
                        </td>
                        <td class=\"iphone_btn_on_right\">&nbsp;</td>
                    </tr>
                </table>

            </div>
        </td>
        <td class=\"iphone_table_leftRight\">&nbsp;</td>
    </tr>
    <tr>
        <td class=\"iphone_table_leftRight\">&nbsp;</td>
        <td>
            <div class=\"iphone_btn_padding\">

                <table border=\"0\" cellspacing=\"0\" cellpadding=\"0\" class=\"iphone_btn\"  onclick=\"set_cookie(\'appLinkIgnoreWeb\',document.getElementById(\'chkDontShow\').checked);goToWeb(\'http://www.website.com\')\">
                    <tr>
                        <td class=\"iphone_btn_left\">&nbsp;</td>
                        <td class=\"iphone_btn_mid\">
                            <span class=\"iphone_copy_btn\">
                                Visit Website.com
                            </span>
                        </td>
                        <td class=\"iphone_btn_right\">&nbsp;</td>
                    </tr>
                </table>

            </div>
        </td>
        <td class=\"iphone_table_leftRight\">&nbsp;</td>
    </tr>
    <tr>
        <td class=\"iphone_table_leftRight\">&nbsp;</td>
        <td>
            <div class=\"iphone_chk_padding\">

                <!-- CHECK BOX -->
                <table border=\"0\" cellspacing=\"0\" cellpadding=\"0\">
                    <tr>
                        <td><input type=\"checkbox\" id=\"chkDontShow\" /></td>
                        <td>
                            <span class=\"iphone_copy_chk\">
                                <label for=\"chkDontShow\">&nbsp;Don&rsquo;t show this screen again.</label>
                            </span>
                        </td>
                    </tr>
                </table>

            </div>
        </td>
        <td class=\"iphone_table_leftRight\">&nbsp;</td>
    </tr>
</table>

</div>

</body>
</html>

回答8:

After compiling a few answers, I\'ve come up with the following code. What surprised me was that the timer does not get frozen on a PC (Chrome, FF) or Android Chrome - the trigger worked in the background, and the visibility check was the only reliable info.

var timestamp             = new Date().getTime();
var timerDelay              = 5000;
var processingBuffer  = 2000;

var redirect = function(url) {
  //window.location = url;
  log(\'ts: \' + timestamp + \'; redirecting to: \' + url);
}
var isPageHidden = function() {
    var browserSpecificProps = {hidden:1, mozHidden:1, msHidden:1, webkitHidden:1};
    for (var p in browserSpecificProps) {
        if(typeof document[p] !== \"undefined\"){
        return document[p];
      }
    }
    return false; // actually inconclusive, assuming not
}
var elapsedMoreTimeThanTimerSet = function(){
    var elapsed = new Date().getTime() - timestamp;
  log(\'elapsed: \' + elapsed);
  return timerDelay + processingBuffer < elapsed;
}
var redirectToFallbackIfBrowserStillActive = function() {
  var elapsedMore = elapsedMoreTimeThanTimerSet();
  log(\'hidden:\' + isPageHidden() +\'; time: \'+ elapsedMore);
  if (isPageHidden() || elapsedMore) {
    log(\'not redirecting\');
  }else{
    redirect(\'appStoreUrl\');
  }
}
var log = function(msg){
    document.getElementById(\'log\').innerHTML += msg + \"<br>\";
}

setTimeout(redirectToFallbackIfBrowserStillActive, timerDelay);
redirect(\'nativeApp://\');

JS Fiddle

回答9:

The date solution is much better than others, I had to increment the time on 50 like that this is a Tweeter example:

//on click or your event handler..
var twMessage = \"Your Message to share\";
var now = new Date().valueOf();
setTimeout(function () {
   if (new Date().valueOf() - now > 100) return;
   var twitterUrl = \"https://twitter.com/share?text=\"+twMessage;
   window.open(twitterUrl, \'_blank\');
}, 50);
window.location = \"twitter://post?message=\"+twMessage;

the only problem on Mobile IOS Safari is when you don\'t have the app installed on device, and so Safari show an alert that autodismiss when the new url is opened, anyway is a good solution for now!

回答10:

Didn\'t read all of these but may be use an iframe and adding the source to, \"my app://whatever\".

Then check regularly on set interval of the page is 404or not.

You could also use Ajax call. If 404 response then app is not installed.