On 09/06/12 00:02, Rob Nickerson wrote:
Fantastic use of the data Nick!
Is there any guides for how to do something similar? I was trying to
visualise the Natural England data using Leaflet but failed miserably
as the shapefile is too big. Your website appears to load just the bit
needed. Would I be able to use some of your code?
One way to only display the data for the area you are displaying is to
use AJAX. Leaflet will give you the bounds of the currently displayed
area, you can get this whenever the map is scrolled or zoomed (with an
event) and fire off an ajax request for the data for that area. Your
ajax request needs to be responded to by something, such as PHP, CGI,
ASP or whatever, that can look up the data for that area, wrap it up in
a useful form and send it to the browser to redraw that area. I use JSON
since the JavaScript in your browser handles this well. For vectors it
is useful to use GeoJSON - Leaflet handles this very well.
On the server side I would load the shapefiles into a database - it
depends what you use on your server - I use MySQL since my cheap and
cheerful host provides PHP & MySQL. This all works with both Leaflet and
OpenLayers - I generally prefer Leaflet.
I wrote blog post [1] [2] about using markers and there is a similar
piece on Switch 2 OSM [3]. maybe Nick would like to write up his vector
display too.
[1] http://chris-osm.blogspot.co.uk/2011/05/leaflet.html
[2] http://chris-osm.blogspot.co.uk/2012/03/more-gb-postcode-goodness.html
[3] http://switch2osm.org/using-tiles/getting-started-with-leaflet/
--
Cheers, Chris
user: chillly
_______________________________________________
Talk-GB mailing list
Talk-GB@openstreetmap.org
http://lists.openstreetmap.org/listinfo/talk-gb
