What's a robust way to detect user region in a web-app?

Question

Possible Duplicate:
How to find the geoip location for all users

I never had to face this problem before so I've been doing a bit of reading on this today but surprisingly haven't been able to find anything really helpful on the topic even though one would think this should be a fairly common issue.

I basically need to detect the user region in a standard web-app and re-direct them to different pages depending on just that.

What's a standard robust way of doing this and does it require a server component or is there a reasonable client side only solution?

Any examples appreciated.

Answer 1

As far as I know, your three sources of data are:

• the user's IP address against a GeoIP database (which requires a server component),
• the user's browser language setting (which apparently still requires a server component), or
• the user's latitude and longitude from their smartphone or modern browser.

I have heard of geolocation services that will abstract away the need for your own server component, some of which were listed on this SO answer.