How do I get DeviceOrientationEvent and DeviceMoti

Question

I'm trying to implement DeviceOrientationEvent and DeviceMotionEvent on my website for a 3D effect. However, the console doesn't log any info and apparently iOS 13 requires a user set permission to start doing this. I can't seem to figure out how to set it up properly.

I've done some research and this is what I found: https://github.com/w3c/deviceorientation/issues/57#issuecomment-498417027

All other methods provided online are not usable anymore sadly.

window.addEventListener('deviceorientation', function(event) {
    console.log(event.alpha + ' : ' + event.beta + ' : ' + event.gamma);
});

I get the following error message:

[Warning] No device motion or orientation events will be fired until permission has been requested and granted.

Answer 1

if ( location.protocol != "https:" ) {
location.href = "https:" + window.location.href.substring( window.location.protocol.length );
}
function permission () {
    if ( typeof( DeviceMotionEvent ) !== "undefined" && typeof( DeviceMotionEvent.requestPermission ) === "function" ) {
        // (optional) Do something before API request prompt.
        DeviceMotionEvent.requestPermission()
            .then( response => {
            // (optional) Do something after API prompt dismissed.
            if ( response == "granted" ) {
                window.addEventListener( "devicemotion", (e) => {
                    // do something for 'e' here.
                })
            }
        })
            .catch( console.error )
    } else {
        alert( "DeviceMotionEvent is not defined" );
    }
}
const btn = document.getElementById( "request" );
btn.addEventListener( "click", permission );

Use an element on your page to use as the event trigger and give it an id of "request".

This will check for https and change it if required before requesting API authorization. Found this yesterday but do not remember the URL.

Answer 2

You need a click or a user gesture to call the requestPermission(). Like this :

<script type="text/javascript">
    function requestOrientationPermission(){
        DeviceOrientationEvent.requestPermission()
        .then(response => {
            if (response == 'granted') {
                window.addEventListener('deviceorientation', (e) => {
                    // do something with e
                })
            }
        })
        .catch(console.error)
    }
</script>

<button onclick='requestOrientationPermission();'>Request orientation permission</button>

Note : if you click on cancel on the permission prompt and want to test it again, you will need to quit Safari and launch it back for the prompt to come back.

Answer 3

As of iOS 13 beta 2, you need to call DeviceOrientationEvent.requestPermission() to access to gyroscope or accelerometer. This will present a permission dialog prompting the user to allow motion and orientation access for this site.

Note that this will not work if you try to call it automatically when the page loads. The user needs to take some action (like tapping a button) to be able to display the dialog.

Also, the current implementation seems to require that the site have https enabled.

For more information, see this page

Answer 4

On Xamarin iOS (Xamarin.Forms) you can inject the permission request script with the EvaluateJavaScript method on the WkWebView when it is ready:

webView.EvaluateJavaScript("DeviceMotionEvent.requestPermission().then(response => { if (response == 'granted') {window.addEventListener('devicemotion', (e) => {})}}).catch(console.error)");

If using a custom WkWebView renderer (must implement IWKUIDelegate if this bug is still around https://bugs.webkit.org/show_bug.cgi?id=203287) the script can be injected when setting the webView control in OnElementChanged

Example:

// do this when setting up the webview control in OnElementChanged
                //enable device motion sensors permission script:
                //https://medium.com/flawless-app-stories/how-to-request-device-motion-and-orientation-permission-in-ios-13-74fc9d6cd140
                var source =
                "function requestSensorPermission() {" +
                "   if (typeof(DeviceMotionEvent) !== 'undefined' && typeof(DeviceMotionEvent.requestPermission) === 'function') {" +
                "       DeviceMotionEvent.requestPermission() .then(response => {" +
                "           if (response == 'granted') { " +
                "               window.addEventListener('devicemotion', (e) => { })" +
                "           }" +
                "       }).catch(console.error)" +
                "   }" +
                "}";
                var script = new WKUserScript(new NSString(source), WKUserScriptInjectionTime.AtDocumentEnd, true);
                wkWebView.Configuration.UserContentController.AddUserScript(script);

Then you can call yourCustomWebView.EvaluateJavaScript("requestSensorPermission()") in your code behind when yourCustomWebView is ready.

EvaluateJavaScript: https://docs.microsoft.com/en-us/dotnet/api/webkit.wkwebview.evaluatejavascript?view=xamarin-ios-sdk-12

Custom WkWebView Renderer: https://docs.microsoft.com/en-us/xamarin/xamarin-forms/app-fundamentals/custom-renderer/hybridwebview#create-the-custom-renderer-on-ios