iphone phonegap google maps memory warning - iphone

Question

I have an app written in Cordova (Phonegap) 2.3.0.
I use Jquery 1.8.2 and jquerymobile 1.2.0 and google maps v3.
XCode version 4.6
On one page I load a bunch of coordinates and creates different polylines added to the map.
There are 37 polylines added to the map and each polyline contains from 20 to 200 coordinates. About 1700 coordinates total on the map.
I also have like 20 markers.
The app works fine from start, I can zoom in and out and the map responds well, but if I reload the map I sometimes start to get messages like "Received memory warning" in XCode and the map wont update any more and sometimes the app crasch.
This is my clear routine that I call before adding the updated data:
function clearOverlays() {
try {
if (polyLinesArray != null) {
for (var i = 0; i < polyLinesArray.length; i++) {
polyLinesArray[i].setMap(null);
polyLinesArray[i] = null;
}
polyLinesArray.length = 0;
}
}
catch(e) {
handleError(e, "clearOverlays");
}
}
polyLinesArray is an array to which I push all polylines after they are added to the map.
So the question is, how can I clear the map in a good way the prevents memory warning (and leaks?)?
I have mouse click listeners too on the polylines, do I need to clear them as well before updating?
The same can occur when I navigate to another html-page in the app. After a few times forward and backward the map wont update any more. Before I navigate to other pages I call my clear routines first.
Another simple test done:
I just load the map, add my polylines and some other markers. Zoom in and out a few times and then the "Received memory warning" appears. I have not done anything else, just let google maps handle the zooming and panning around.
Regards
Henrik

Answer 1

I had the same issue and found out that it had to do with the way the Google Maps API draws overlays. For some reason this became too memory intensive from API 3.7 and up. Luckily in 3.12 (current experimental version) this seems to be resolved again. At least in my case.
If you call the maps api with &v=3.exp in the URL, your issue might be resolved as well.