Geographical Services?

This is a broad question to get me started in the right direction:

I would like to provide a location-based service so that users can tag
articles with a location (the place where the article took place), and
search (or list) articles by location.

This raises some questions:

  • Presumably best practice is to allow the user not to type free-form
    locations, but to help them pick a location from a list?

  • Are there any frameworks that handle geographical hierarchies? For
    example, an article may be tagged with a city name, and a user may want
    to list all articles for a county, we’d need to know all of the cities
    in each county or we’d return nothing.

The simplest thing may be to just have a flat list of places, with no
hierarchy, a list of cities and major towns for example?

Any broad advice on what’s out there to provide any
geographical/location services would be much appreciated!

Thanks!

Peter L. wrote:

I’m not going to be able to help this yet, but just to add to it. What
level of granularity do you want to provide? Can people search by the
places within a city? How about different shops/ outlets within a
city? Does it matter which branch generated the document?

Cheers,
Mohit.
8/23/2009 | 8:08 PM.

are you looking to connect with something like: www.geonames.org

I’m not going to be able to help this yet, but just to add to it. What
level of granularity do you want to provide?

For me, I could really get away with a flat list of worldwide cities,
which I guess would be the least level of granularity possible. However,
a 2-level service would be good so we would have a hierarchy of
county/parish<->city. Of course, for very large cities such as London,
it would be good to be able to split them further.

So in a nutshell, for my needs I think I could get by with a sensible
worldwide flat list, but if there’s a good, easy to integrate, worldwide
2-level service/framework, that would be great for me.

As for shops and outlets, that level of granularity would be a bit too
much for me, but actually, thinking about it, might be interesting!

I guess I was fishing around for clues on what was available.

Marion Taylor wrote:

are you looking to connect with something like: www.geonames.org

That is pretty good!

There appear to be some basic ways of digging through the hierarchy too
(e.g. finding the country for a city etc.).

This looks like what I needed, thanks.

Peter
if www.geonames.org is what you need, also check out:
www.gis.com
GNIS Feature Search (which seems to be an application using
geonames.org)

and others via google: geographical database

You may or may not have seen this too, but it is a big part of every
geocoding Rails app I build:

http://geokit.rubyforge.org/

It adds a number of geocode-specific methods to ActiveRecord which
allow you to query records based on their proximity to a location
(e.g. @locations = Location.find(:all, :origin => @address, :within =>
@within, :order => ‘distance’)). It can also automatically geocode a
location upon create using either Google, Yahoo, or GeoNames. You
provide your API key and GeoKit handles the grunt work. Very handy
tool. :slight_smile:

Good luck with your project.

On Aug 23, 7:54 am, Peter L. [email protected]

PS you might want to also check out:
www.extonrails.com
Country, region, city ruby wrapper for geonames.org | Ext on Rails

I second Geokit, I’ve used it in almost every application I’ve built.
However, the main purpose of geokit is for getting the latitude and
longitude of a location and then performing distance calculations
between
that location and other locations (such as finding all locations within
a
certain distance of another location).

If you want to do something such as list cities or counties, you’ll
probably
need to get something like a ‘location database’ and slice and dice it
for
your needs. Unfortunately they usually cost money.

An alternative solution to showing all the articles in the same county
as a
city would be to use geokit to show all the articles within a certain
distance of a city. That could provide your users with a similar
experience.

Hope that helps.

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