make a local copy of mapbox assets

mapbox_gruntfile.js

 grunt.registerTask('mapbox', function() {
    var version = this.options().version;
    console.log('mapbox v' + version);

    var baseUrl = 'https://api.tiles.mapbox.com/mapbox.js/v'+version+'/';

    //async task
    var done = this.async();

    //reset mapbox folder in bower_components
    exec('rm -rf app/bower_components/mapbox.css');
    exec('rm -rf app/bower_components/mapbox.js');

    //grab latest mapbox js and css files through bower
    exec('bower install mapbox.js='+baseUrl+'mapbox.js --save', function(err, stdout, stderr) {
         console.log(stdout);
         exec('bower install mapbox.css='+baseUrl+'mapbox.css --save', function(err, stdout, stderr) {
             console.log(stdout);
             prepareStyles();
         });
    });

    //rename mapbox css to scss, move it to styles, replace image links with local versions (donwloaded later)
    function prepareStyles() {
        var scssPath = 'app/assets/styles/mapbox/mapbox.scss';
        fs.writeFileSync(scssPath, fs.readFileSync('app/bower_components/mapbox.css/index.css'));

        var scss = fs.readFileSync(scssPath).toString();

        scss = scss.replace(/url\(images\//g, 'url(../images/mapbox/');
        fs.writeFileSync(scssPath, scss);

        fetchImages();
    }

    //fetch mapbox image assets 
    function fetchImages() {
        process.chdir('app/assets/images/mapbox/')

        exec('curl -O '+baseUrl+'images/icons-000000.png', function(err, stdout, stderr) {
            exec('curl -O '+baseUrl+'images/icons-ffffff.png', function(err, stdout, stderr) {
                exec('curl -O '+baseUrl+'images/[email protected]', function(err, stdout, stderr) {
                    exec('curl -O '+baseUrl+'images/[email protected]', function(err, stdout, stderr) {
                        done();
                    });
                });
            });
        });
    }
  });