Highlighting borders of state and cities of US in Google Map API 3

Question

I have a scenario where I have to highlight borders and shade a state or city after geocoding it (when I got the lang and lat).

How can I do this, do I need to have a complete information of a city to surround it with polylines? Or is there a way that map API can do this for me.

Answer 1

True. Google does not provide this feature. So what we can do... we can have the lat/long of the borders of the state. And we have to draw polygons ourselves.

I used this JS object. And changed it to Google map object (google.maps.LatLng).

For example:

var statesobj = {"AK": [new google.maps.LatLng(70.0187, -141.0205),
new google.maps.LatLng(70.1292, -141.7291),
new google.maps.LatLng(70.4515, -144.8163)]}

So, it's easy now. Loop on these lat/longs. And you can draw the polygons on every state of US.

So this is the solution I came up. If you guys know some better idea to do it. Please share.

Answer 2

You can also try Google Geo Charts:

http://code.google.com/apis/chart/interactive/docs/gallery/geochart.html

Answer 3

Google Maps API doesn't allow you to retrieve city borders. There are a couple other places from which you can get the coordinates, though:

Flickr API

There is a Flickr API based on photos that people tag, but it's only as accurate as the people who tag photos: so it's good enough for bootstrapping but probably not for production: http://karya-blog.blogspot.com/2012/12/fetching-city-polygons-with-flickr-api.html

Natural Earth Data

An accurate alternative is www.naturalearthdata.com. To get that data from there you just need to make two requests: one with the city name and one with their ID to get the parameters:

unlock.edina.ac.uk/ws/search?name=berlin&gazetteer=naturalearth&format=json

and then

unlock.edina.ac.uk/ws/footprintLookup?format=json&identifier=14126951

and you're set :)

Mapzen

If it's possible for you to pre-fetch the data, go for Mapzen, they have a full and pretty accurate database: https://mapzen.com/data/borders/