@mapnik/mapnik/bin/mapnik-render.js

Node.js bindings for Mapnik (mapnik.org)

#!/usr/bin/env node

"use strict";

var fs = require('fs');
var path = require('path');
var child_process = require('child_process');

var usage = 'usage: render.js <stylesheet> <image>';

var stylesheet = process.argv[2];
if (!stylesheet) {
   console.log(usage);
   process.exit(1);
}

var image = process.argv[3];
if (!image) {
   console.log(usage);
   process.exit(1);
}

var mapnik = require('../');

mapnik.register_default_fonts();
mapnik.register_default_input_plugins();

function renderMap(stylesheet, image) {
    var map = new mapnik.Map(600, 400);
    map.loadSync(stylesheet,{strict:true});
    map.zoomAll();
    map.renderFileSync(image);
    child_process.exec('open', [image]);
}

if (path.extname(stylesheet).match(/.mml/i)) {
    try {
        var carto = require('carto');
        new carto.Renderer({
            filename: stylesheet,
            local_data_dir: path.dirname(stylesheet)
        }).render(fs.readFileSync(stylesheet, 'utf-8'), function(err, output) {
            if (err) {
                if (Array.isArray(err)) {
                    err.forEach(function(e) {
                        carto.writeError(e, {});
                    });
                }
                process.exit(1);
            } else {
                fs.writeFileSync(
                    stylesheet.replace('mml', 'xml'),
                    output, 'utf-8');
                stylesheet = stylesheet.replace('mml', 'xml');
                renderMap(stylesheet, image);
            }
        });
    } catch (e) {
        console.log('Carto is required to render .mml files.');
        process.exit(1);
    }
} else {
    renderMap(stylesheet, image);
}