Embedded Google map with filtering

[Geoff]

I want to embed a Google map on a web page and show results based on a postcode and a distance from said postcode. Any ideas?

[tom_newton]

You may find a service to do this. DIY is harder.

Roughly the steps are:

* find a georeferencer - pref one that gives postcode->national grid NOT lat long. This is hard-ish, as the data costs money, though there are free datasets out there, they have a range of issues (dubious provenance, out of date, low accuracy) which may or may not bother you. Last I looked Google did not provide a postcode georeferencing service.

* Georeference your "nearest" locations. Store x,y

* when you get a query, georeference the postcode, and then compare pythagorean distance to all the others, and sort them (can be done entirely in SQL). This isnt fast, but for small datasets (<1k), all optimisations are worthless

* create KML from the results and pass to google maps

 

I'm *very* rusty with the old map work... been out of it a long time, but still maintain a passing interest. You might find that Google needs lat long in KMl, in which case i'd store both nat grid, and ll in your DB. Nat grid is nice as we are a small country we can grid our maps without losing a lot of accuracy. Grid means "distance" and other fun things are easy to calculate.

[Geoff]

Ok. I get the gist of that. I dislike having to DIY it too. Any services that are likely to do my job for me?

[Geoff]

Huzzah!

 

GMapEZ -- Get Started

[tom_newton]

Arr.

Looks like you still need to do some georeferencing - though you could do this for very small datasets by firing the postcode at google maps and getting the URL back - but you still need to georeference the "input" postcode (I presume you are doing something like a "storefinder").

[Geoff]

I believe this solves the georeferencing problem?

 

The Google Geocoding API - Google Maps API Web Services - Google Code

 

and yes, it's a storefinder kind of thing.

[tom_newton]

Cool. Will that georeference a single postcode?

 

I'd cache your results in your db mind.

[Geoff]

Would appear to! Try it yourself (open the file in a program that understands UNIX type text files)

 

http://maps.google.com/maps/api/geocode/json?address=LS12 6QA&sensor=false

 

Don't even need an API key

[Arthur]

There's a really good Google Maps plug-in for jQuery called gMap which should do what you want. See the examples page for info on how to use it.

[tom_newton]

Mint. I might now georeference our customer db for a laugh