Question

1. I am not doing a large chunk of computation in JS.

2. Everything works fine on iPad iOS 5 in Safari until I added this code:

   var watchID = navigator.geolocation.watchPosition(updatePos,locationError,{maximumAge: 10000, frequency: 60000, enableHighAccuracy: true, timeout: 1000});
   
   function updatePos(position) {       
       if (position.coords.accuracy < accuracyThreshold) {                 
           $.post(websiteRoot + '/ReportDeviceLocation?rand=' + (Math.random() * Math.random()) + '&longitude=' + position.coords.longitude + '&latitude=' +position.coords.latitude);
   
       } else {
           console.debug("Location data is not accurate enough. Location not updated.");
       }
   }
   

3. Then the web page worked for about 4 minutes and I get this error:

   JavaScript execution exceeded timeout.

4. Then no JavaScript would load. None of the debug messages I inserted into my.js file would print. Only the above error.

5. The error persists even after I left the page that generated this error, and opened other web pages under the same domain.

6. I used try and catch, I used setTimeout function, but neither gave me the source of the error nor solved the problem.

I don’t know what the problem is. It has been burning me for the entire day and will be burning me for the weekend.

Answer 1

Surprisingly, when I used geolocation.getCurrentPosition, the error message stopped showing up.
To replace watchPosition with getCurrentPosition, I use the function setInterval:

        function getLocation() {
            navigator.geolocation.getCurrentPosition(updatePos, locationError, { enableHighAccuracy: true, timeout: 10000 });
        }

        var intervalID = window.setInterval(getLocation, 10000);

This has worked out better than watchPosition because watchPosition sometimes does not follow rules(update location 8 times in 3 minutes despite the frequency is set to 10 minutes).

If the timeout still occurs, one would need to call clearInterval:

var geolocationID;
(function getLocation() {
     var count = 0;
     geolocationID = window.setInterval(
       function () {
            count++;
            if (count > 3) {  //when count reaches a number, reset interval
                window.clearInterval(geolocationID);
                getLocation();
            } else {
                navigator.geolocation.getCurrentPosition(updatePos, locationError, { enableHighAccuracy: true, timeout: 10000 });
            }
        },
        600000); //end setInterval;
})();