Adding SVG overlay to nokia HERE map - svg

Question

I'm working with nokia HERE maps and I want to add an additional layer of visualization graphics on top of a map. Since the possibilities to interact, manipulate and customize the graphics created by the HERE api are limited, I would like to work with d3.js/SVG for my visualizations.
My straight forward and obvious solution would have been to just add an absolute positioned SVG element on top of the map and giving it the same dimensions. But of course that takes every possibility to interact with the map. Is there any solution to add an overlay to the map which allows me to put SVG on it while maintaining the full interactivity (panning, zooming, clicking) of the map? Also it should be possible to interact with the SVG.
I know that there is a possibility to add a custom overlay of tiles provided by a tile server to HERE maps but that's not really what I'm looking for. I'm looking for something like the solution google has to offer to this problem. A set of custom layers which are always in sync with the corresponding map and have their own initialize, draw and remove methods. Is there something similar for HERE maps?

Answer 1

I think you are after the nokia.maps.map.provider.CanvasProvider class. This class provides a ground overlay bound to a specific area which offers a draw() method. The attach() method is the equivalent of your intialize I think, and you can refresh the overlay using update().
Depending upon your use case, I've also found the following techniques useful regarding SVG, Images and HERE Maps:
For an SVG marker which is anchored to a point and doesn't resize
use: SVG Markers
Alternatively override the Marker class and write using the low
level graphics commands to add flexibility to the rendering of a
marker anchored to a point. Like this: Defaced Marker
To add an image bound to a specific area use the ImageProvider class
To add a series of tiled images from a TMS (Tile Map Service) use the ImgTileProvider class
Alternatively if the [zoom][col][row] is useful to you and you
want to write SVG based stuff yourself try something like this example - which combines
SVG with 256x256 pixel markers.
Note that the HERE Maps API for JavaScript only supports SVG Tiny.

Answer 2

A class like the old nokia.maps.map.provider.CanvasProvider isn't even available on the new v3 API from Here.
Your best bet is on Leaflet using custom providers loading Here map tiles. Then you just load this Custom Overlay class and you're all set to draw D3, WebGL, whatever you need. Leaflet only loads the tiles from the providers and exposes some simple APIs. You will not have to deal with any of the providers' APIs.
Just don't forget to add your app_id and app_code to the provider class.