Google maps API works when I break then continue, doesn't otherwise
This code works when I break any time after pos is defined, then continue. But when I run it normally it doesn't display anything. What am I doing wrong?
function initialize() {
var pos;
if(navigator.geolocation) {
navigator.geolocation.getCurrentPosition(function(position) {
pos = new google.maps.LatLng(position.coords.latitude,
position.coords.longitude);
}, function() {
handleNoGeolocation(true);
});
}
else { // Browser doesn't support geolocation
handleNoGeolocation(false);
}
var myOptions = {
zoom: 7,
center: pos,
开发者_StackOverflowmapTypeId: google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map(document.getElementById("map_canvas"),
myOptions);
}
getCurrentPosition(f, ...)
is asynchronous, meaning that the callback f
is called later after successful completion of the request. But at this time the local variable pos
in the function initialize()
is no longer in scope.
You can solve the problem by defining pos
in the global window scope. This should work and pos
will get assigned by the callback. However, you do not know when this assignment happens. The best way to handle this problem, is to do something with pos
directly in the callback, e.g. write it into a text field or store it in the database, etc.
Interesting. Are you getting errors? Can you share? You might also want to use console.log() for debugging and wrap try/catch blocks around that. I think you might have some issues in some of the older browsers.
Maybe the API call takes a little bit of time and when it breaks it gets that little bit of time to retrieve whatever data it needs, so it is able to display it? This is merely speculation but you could try putting a delay in there to see what happens.
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