[OpenLayers-Dev] preliminary UTFGrid support in OpenLayers

[Andreas Hocevar]

Hey Matt,

thanks for your work on this. The fact that you haven't gotten an
answer from one of the core developers earlier does not mean that
nobody is interested - it's just that everybody is busy I guess. I'd
like to take a look at the code, and I'm hoping to find some time to
do so soon, so I can give some feedback.

Andreas.

On Thu, Feb 16, 2012 at 8:08 PM, Matt Perry <perrygeo at gmail.com> wrote:
> Hey all - I'm excited to share my implementation of OpenLayers support
> for UTFGrids. I wanted to get some feedback before doing a pull
> request.
>
> Just a little background: UTFGrids are json "hit grids" used to
> provide a high degree of interactivity. For example, you can have
> mouseover events that display the attributes of the features *without*
> fetching additional data from the server. The best demo of the concept
> is probably http://mapbox.com/demo/visiblemap/.
>
> This functionality exists in the wax library and is largely deployed
> with ModestMaps. I've ported it to native OpenLayers code to better
> integrate with OL event handlers and such. There are three additional
> components: a UTFGrid Layer, Control and Tile. It has both ajax and
> jsonp loading protocols, tries to keep a clear separation between the
> grid layers, the grid controls and callbacks which allows things like
> multiple handlers and multiple hit grids per map.
>
> Some example code:
>        var world_utfgrid = new OpenLayers.Layer.UTFGrid(
>            'UTFGrid Layer',
>            "http://tiles.example.com/world_utfgrid/${z}/${x}/${y}.json"
>        );
>        map.addLayer(world_utfgrid);
>
>        var control = new OpenLayers.Control.UTFGrid({
>            'div': 'attrsdiv',
>            'layers': [world_utfgrid],
>            'handlerMode': 'move'
>        })
>        map.addControl(control);
>
>
> Some demos:
> http://labs.ecotrust.org/utfgrid/events.html
> http://labs.ecotrust.org/utfgrid/multi.html
>
> and source:
> https://github.com/perrygeo/openlayers/tree/utfgrid
>
> Any thoughts on getting this into 2.12? This is my first substantial
> effort in extending OpenLayers so if you have any critiques or
> concerns that need to be addressed before a pull request would be
> considered, let me know.
> --
> ·´¯`·.¸. , . .·´¯`·.. ><((((º>`·.¸¸.·´¯`·.¸.·´¯`·...¸><((((º>
> "The best way to predict the future is to invent it."  -- Alan Kay
> Matthew T. Perry
> http://www.perrygeo.net
> http://viedevelo.wordpress.com
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-- 
Andreas Hocevar
OpenGeo - http://opengeo.org/
Expert service straight from the developers.