Google Spreadsheet Data API

I gave a presentation to the U. of Delaware WebDev group and IT-CS&S (RDMS) on the topic of using data from Google Docs Spreadsheets for consumption in a scripted workflow. I’m using this in the UD Map for automatically incorporate rendering decisions from OCM. The gist is that you open an https stream with headers…

Zoom to extent of new vector layer in OL

Zooming to the maximum extent of all features in a vector layer does not work unless all features have been loaded. Therefore it is necessary to register an event handler, as demonstrated below (‘layer’ is any object of class OpenLayers.Layer.Vector): layer.events.register(‘featuresadded’, map,function(){this.zoomToExtent(layer.getDataExtent())});

Mapnik label cut off strategies

I’ve been spending a lot of time dealing with mapnik labels/shields being cut off. Here are some strategies: change the “buffer_size” property of the map object in the mapnik xml … you can also direclty change this in generate_tiles.py (which comes with osm mapnik package). I don’t think the mapnik xml was being read in…

Mapnik … success!

Here’s how I imported, rendered, and served OSM data through mapnik, locally: 1. Do all downloads/installs … python (2.5 worked for me), postgres/postgis (8.3 worked), osm2pgsql, mapnik, rendering/mapnik utilities for OSM2. Follow info below on osm2pgsql3. Make sure mapnik bindings are registered with Python, run the demo under demopython to make sure mapnik works, here…

OSM2PGSQL

After getting mapnik installed and running I realized: 1. generate_tiles/generate_xml (and the rest of the render utilities) are really necessaryfor rendering OSM through mapnik. Therefore, you must download both mapnik through the mapnik site but also the mapnik OSM rendering tools which you can get through SVN at http://svn.openstreetmap.org/applications/rendering/mapnik/2. you must download world coastlines to…