Coalition

An illustrative web server that combines nodejs, mapnik, and postgis.

Depends

NodeJS > 0.2.4

Mapnik (latest trunk >r2397)

Node-mapnik

Npm / Spark

Installation

Install node:

$ wget http://nodejs.org/dist/node-v0.4.0.tar.gz
$ tar xvf node-v0.4.0.tar.gz
$ ./configure
$ make
$ make install

Install node-mapnik:

$ git clone git://github.com/mapnik/node-mapnik.git
$ cd node-mapnik
$ ./configure
$ make
$ make install

Install npm (node package manager)

$ curl http://npmjs.org/install.sh | sh

Install spark via npm:

$ npm install spark

Configuration

Edit the postgis settings in 'server/settings.js' to match your system.

Also, fixup the few hardcoded sample queries in 'public/index.html' to match your postgis tables.

Usage

Start the server by typing:

$ ./run.sh

Or:

$ spark

Then visit http://localhost:3000/. Choose a style type and a postgis subquery.

A note on styles

Mapnik supports applying arbitrary styles to layers, but for the results to be reasonable you have to apply reasonable styles. For example a PointSymbolizer will work against either point geometries or polygon geometries, but a PolygonSymbolizer will not render anything if applied to point geometries.