Question

I would appreciate any help in solving this – or at least where to look to solve it.

What I have is calling on iPhone navigator.compass.getCurrentHeading(succ, fail), the success function is called every time the device is moved even slighly. In the XCode debug log I see lots of entries of navigator.compass.setHeading calls being generated for every movement. If I try to poll for heading data again – the request just hangs. Here’s the code:

function onBodyLoad() {
    if (typeof navigator.device == "undefined") {
        document.addEventListener("deviceready", onDeviceReady, false);
    } else {
        onDeviceReady();
    }
}

function succ(heading) {
    alert("compass " + heading);
}

function fail() {
    alert('fail');
}

function onDeviceReady() {
    navigator.compass.getCurrentHeading(succ, fail);
}

This is really strange behaviour, as I expect getCurrentHeading to be called just once and return a single result, instead of the unstoppable flurry of events.

I use PhoneGap 1.0.0. The same code on Android works perfectly. I’ve removed all custom JS code to prevent possibility of conflicts.

Answer 1

It is odd that noone else seems to encounter this. In any case, this (hacky) solution may help anyone who comes looking for an answer.

We had to stop using getCurrentHeading because of this issue, and replaced it with navigator.compass.watchHeading instead. On clearing the watch we also call navigator.compass.stop() function to prevent from further compass spamming (for iPhone platform only – Android is fine), and before calling watchHeading again we call navigator.compass.stop() and navigator.compass.start(), to reinitialize the compass “just in case” (again, on iPhone only).

After taking these measures the page that user compass no longer hangs on second entry, and there is no heading spamming outside of this page.