Deep linking an app in PHP is not working - php

Question

I have a webpage that needs to check to see if an app exists using a deep link, but it doesn't seem to work like it should. I have tried the following things.
Using a redirect in PHP (Doesn't work)
header('Location: exampleapp://param=test');
Using a redirect using JavaScript (Doesn't work)
var appurl = 'exampleapp://param=test';
var appstore = 'https://itunes.apple.com/us/app/...';
var timeout;
function preventPopup() {
clearTimeout(timeout);
timeout = null;
window.removeEventListener('pagehide', preventPopup);
}
function startApp() {
window.location = appurl;
timeout = setTimeout(function(){
if(confirm('You do not seem to have the App installed, do you want to go download it now?')){
document.location = appstore;
}
}, 100);
window.addEventListener('pagehide', preventPopup);
}
// app start is then called in the onload
Same as above but replace the the line window.location = appurl; with document.getElementById('deeplink').click(); and adding a link in the html's webpage. (Works) <a id="deeplink" href="exampleapp://param=test">Deep Link</a>
Is there a reason why you can't redirect using a header in PHP?

Answer 1

The PHP version doesn't work, because of the way HTTP works. The HTTP protocol doesn't specify that it should work to redirect to a different protocol from within the "Location:" header. There is nothing specific to PHP here, it's a HTTP issue.
The Javascript version doesn't work because you wanted to set the windows location. And the window cannot show the contents of "exampleapp://..." . You want the link to open like when the user clicks on it. Instead of using window.location you may use document.location.href. That should work.
Another problem:
in your code you write exampleapp:// in 1) and 2). And in 3) you write testapp:// - make sure you use the same URL in all three cases, so that you can be sure that the URL can work eventually..

Answer 2

The answer is to use Apples implementation called 'Smart Banners'
<meta name="apple-itunes-app" content="app-id=myAppStoreID, affiliate-data=myAffiliateData, app-argument=myURL">
You can include three comma-separated parameters in the content
attribute:
app-id: (Required.) Your app's unique identifier. To find your app ID
from the iTunes Link Maker, type the name of your app in the Search
field, and select the appropriate country and media type. In the
results, find your app and select iPhone App Link in the column on the
right. Your app ID is the nine-digit number in between id and ?mt.
affiliate-data: (Optional.) Your iTunes affiliate string, if you are
an iTunes affiliate. If you are not, find out more about becoming an
iTunes affiliate at http://www.apple.com/itunes/affiliates/.
app-argument: (Optional.) A URL that provides context to your native
app. If you include this, and the user has your app installed, she can
jump from your website to the corresponding position in your iOS app.
Typically, it is beneficial to retain navigational context because: If
the user is deep within the navigational hierarchy of your website,
you can pass the document’s entire URL, and then parse it in your app
to reroute her to the correct location in your app. If the user
performs a search on your website, you can pass the query string so
that she can seamlessly continue the search in your app without having
to retype her query. If the user is in the midst of creating content,
you can pass the session ID to download the web session state in your
app so she can nondestructively resume her work. You can generate the
app-argument of each page dynamically with a server-side script. You
can format it however you'd like, as long as it is a valid URL.
https://developer.apple.com/library/ios/documentation/AppleApplications/Reference/SafariWebContent/PromotingAppswithAppBanners/PromotingAppswithAppBanners.html