I would like to show some specific data when user mouseover the polyline in google map. I get LatLng object in in mouseover event. I would like to save custom field (index to another array with data to show) to the LatLng object, so I don't need to scan another collection.
I am not expert on Javascript. Can I add a custom property to LatLng or can I inherit/extend myLatLng object? What is the best approach?
google.maps.event.addListener(polyline, 'mouseover', function (event) {
var indexOfPointInPolyline = SomeFunc(event);//I don't know how to do this properly
});
Basically a LatLng is an object, you can assign any property you want to via:
obj.myProperty='myValue'
for the given code it would be like:
event.latLng.someProperty='someValue';
But: this will not work because:
the mouseover-event will always pass a new LatLng-instance
it's also useless to implement other solutions based on the coordinates. When you log the returned values you'll see that they are always different(the accuracy will be up to centimeters or even millimeters ), it's nearly impossible for a user to touch a polyline repeatedly at the exact same point.
Related
I have a LeafletJS map with a GeoJSON layer that contains multiple polygons. If a user enters a latitude/longitude coordinate that falls within the GeoJSON layer, the script should retrieve the feature that contains that point and log some information about it to the console.
I can't simply use Leaflet's built-in event handling because the latitude and longitude coordinates are generated by a separate input field, not by direct interaction with the map. So my question is not a duplicate of this.
I'm looking for something similar to getFeatureContainingLatLng() in the example below:
var map = L.map('map');
var geojson = L.geoJson(myGeojson);
geojson.addTo(map);
$.on('address input changed event', function(lat, lng) {
var myFeature = geojson.getFeatureContainingLatLng(lat, lng);
console.log(myFeature.properties);
});
The plugins Leaflet.CheapLayerAt or Leaflet-pip should help. Both approaches will solve your problem, albeit they have different advantages and disadvantages specially in terms of algorithmic complexity.
I am displaying two different leaflet maps in the same page. After a certain event. I want a Polyline to appear on both of them. I would like to avoid, if possible, to create a copy and keep two different variables.
I am trying yo use the following:
var line_coordinates = [[1,2],[3,4]];
var my_polyline = L.polyline(line_coordinates);
my_polyline.addTo(map1);
my_polyline.addTo(map2);
However, if I run the above code, the Polyline will be displayed only on the map2.
Afterwords, I will need to change again its coordinates to some new_line_coordinates, and I will run the following:
my_polyline.setLatLngs(new_line_coordinates);
my_polyline.redraw();
The polyline should now appear updated to the new coordinates. However, again, it appears only on map2.
What am I doing wrong? Is it possible to achieve what I am trying to do?
As geocodezip mentioned in a comment, adding a polyline to a map sets the polyline object's this._map instance variable. Therefore, there is no way to have the object rendered on both maps with the way in which it is currently implemented.
You can view the relevant source code here.
You can't add the same layer to multiple Leaflet maps. But I had a similar problem using a more complex GeoJSON layergroup and ultimately solved it by getting the GeoJSON object from the layer using toGeoJSON() and using it to create a new layer for the second map. For a simple polyline, you could use getLatLngs(). So:
var line_coordinates = [[1,2],[3,4]];
var my_polyline = L.polyline(line_coordinates);
my_polyline.addTo(map1);
var new_polyline = L.polyline(line_coordinates);
new_polyline.addTo(map2);
should work, as would:
var line_coordinates = [[1,2],[3,4]];
var my_polyline = L.polyline(line_coordinates);
my_polyline.addTo(map1);
var my_polyline_latlngs = my_polyline.getLatLngs();
var new_polyline = L.polyline(my_polyline_latlngs);
new_polyline.addTo(map2);
I want to push a custom var to dynamically loaded Google Maps markers (with live user positions) {via javascript}. In this case, I want to push a UNIX timestamp into the marker, so that way I can keep track of marker timing. After a set interval, JS scans for markers timestamps that reach an expired time period -> then remove them.
I wanted to see if any one else played with this similar idea.
The good thing about the Google Maps API using Javascript is that the objects you create function just as any other object or variable you would usually find in Javascript.
This means that you can easily push a new var into the marker. I have done this myself a couple of times and it works like a charm :)
Simply go :
var marker = new google.maps.Marker();
marker.timestamp = WHATEVER_YOU_WANT;
i need some help with google map api v3 markers.
I got an array which contains coordinates i retrieve from a file. I am trying to traverse the array, and plot them using the markers.
Traversing the array to retrieve the coordinates is not a problem, however, when i start using the coordinates to plot on google map. i realise that i am getting (NaN, NaN) as the coordinates.. Because of this, i am not able to do the plotting.. any idea why isit? Thanksss
my codes so far:
var temp = new google.maps.LatLng(myObject[o]);
retrieverouteMarker(temp);
The constructor for LatLng takes two arguments (the latitude and longitude of the point), so this line is clearly wrong:
var temp = new google.maps.LatLng(myObject[o]);
Of course, since we have to idea what myObject is, or what the function retrieverouteMarker does, there isn't much more we can do to help.
I currently have a implementation where some markers coming from JSON list is shown, on a particular area, Now I want to filter these marker depending upon some criteria, I have done the filtering part, and got the filtered list. Now to render this markers on the map again, The current implementation loads the js with a key again, also creates the GMap2 object and draws the list of marker on the newly created map, which is really annoying. I want map to be there and only markers to be added and removed from the map.
Any help is appreciated
You can use addOverlay and removeOverlay to add/remove markers from an already displayed map. See the examples here: http://code.google.com/apis/maps/documentation/overlays.html#Markers
var latlng = new GLatLng(lat, lng);
map.addOverlay(new GMarker(latlng));
You can make drawMap() and drawMarkers() as two separate functions. And after map has been created redefine drawMap to empty function like this:
drawMap = function(){}; After that only drawMarkers() will be executed.
Hope this is what you need. If not, provide some code.