[OSM-dev] Clickable POIs - use marker/pushpin layer?

[Richard Fairhurst]

John McKerrell wrote:

> An advantage of using markers is the ability to give instant
> feedback, changing the mouse cursor to indicate that this is
> something you can actually interact with. It's possibly to do this
> without markers too but they are the simplest way.

It's hacky, but the Sustrans map has exactly the right approach on  
this - an invisible imagemap with a bit of JavaScript behind it.

_But_ I suspect this would boggle our servers too much (it certainly  
does theirs ;) ) , so it would almost certainly have to be cached per  
tile and then aggregated within OL, and good luck coding that.  
(Seriously, good luck. I'd love to see it.)

But again, please, please don't ruin the cartography by putting a  
whole load of markers all over it. To do this without the map looking  
like a bollocks, you'd have to code automatic placement routines to  
stop two markers appearing at the same place; and even then, they'd  
overlay the road/place names so carefully placed there by  
Mapnik/Osmarender.

If you do want to go the marker route, then it absolutely needs to be  
a separate layer which is not on by default. This might save server  
load, too.

Apologies for sounding like a cartofascist/palaeoStalinist. :)

cheers
Richard