Backbone.js fetch issues with Google Maps - backbone.js

Question

With backbone I am fetching results from Google maps to return markers of places where the user is. The results populate a collection which I clear everytime the user moves the map as a new fetch occurs based on the new location bounds (I am using the google map idle event to get this information and changing the URL of the collection).
To manage the markers I populate an array with each marker.
The issue I am having is I get the first set of markers but it does not write in any new markers when the map is moved and when you inspect the markers array its the same results as last. If I do an AJAX call I get the desired results, but I want to keep this all within a backbone collection as I do other processes with the model.
/* Tracking Page Items */
var allPlace = Backbone.Model.extend({
createMarker:function(){
var marker = new google.maps.Marker({
position: this.getLatLng(),
title: this.get("name"),
location_type: this.get("type")
});
return marker;
}
});
var MarkersCollection = Backbone.Collection.extend({
model: allPlace,
url:function(){
return '/'
}
})
var markersArray = [];
var mapAll = Backbone.View.extend({
initialize: function() {
_.bindAll(this, 'render', 'createMarkers'); // get access to this in other methods
this.collection.bind('reset', this.render, this);
},
render: function() {
// Load map scripts and initialise
if(typeof google === "undefined"){
nzp.loadGoogleMap();
} else {
nzp.initializeMap();
};
// Current location
myLocations = {
lat: this.collection.lat,
lng: this.collection.lng
};
// Listen for map movement
var self = this;
google.maps.event.addListener(map, 'idle', function() {
var bounds = map.getBounds();
var lat1 = bounds.ca.b;
var lng1 = bounds.ea.b;
var lat2 = bounds.ca.f;
var lng2 = bounds.ea.f;
self.showMarkers(lat1, lng1, lat2, lng2);
});
},
// update URL based on new bround
showMarkers: function(lat1, lng1, lat2, lng2) {
var markerCollection = new MarkersCollection;
nzp.infoWindow = new google.maps.InfoWindow();
lat = myLatlng.Xa;
lng = myLatlng.Ya;
lat1 = lat1;
lng1 = lng1;
lat2 = lat2;
lng2 = lng2;
// Collection URL build from parameter adn current location
markerCollection.url = "http://blah.com/locator/api/locations?api_key=XXX&nearby_latitude="+lat+"&nearby_longitude="+lng+"&lat1="+lat1+"&lng1="+lng1+"&lat2="+lat2+"&lng2="+lng2+"&max=10&format=jsonp&callback=?";
// Fetch collection
markerCollection.fetch({
success: function(results) {
// Clear the markers array
for (i in markersArray) {
markersArray[i].setMap(null);
}
markersArray.length = 0;
// Loop over items in collection
results.map(function(item){
var marker = item.createMarker();
marker.setMap(map);
// Create a marker based on each item
(function(marker, item) {
google.maps.event.addListener(marker, "click", function(e) {
nzp.infoWindow.setContent(infowindowContent(item)); // Info window content is processed in a method within the model
nzp.infoWindow.open(map, marker);
});
// Place each marker in the markers arrya
markersArray.push(marker); // Push markers into an array so they can be removed
})(marker, item);
}, this);
}
});
// Set markers to vidsible
$.each(markersArray, function(index, item){
markersArray[index].setVisible(true);
});
});

Answer 1

Fixed this. The issue was related to the values being passed to the API and not how I was updating the collection URL as I thought.
I was passing a bounds and a current location and bounds which was causing the API to always return the same results. The working AJAX version I had of the code had a typo in the URL which actually allowed the API to return the correct results.