node-watch-for-handlebars.js

watch = require('watch');
fs = require('fs');
var cmd = require('child_process').spawn('cmd'), myArgs;

console.log('watcher started');

myArgs = process.argv.slice(2);
myDir = myArgs[0];
outDir = myArgs[1] || '';
outDir = stripTrailingSlash(outDir);

watch.createMonitor(myDir, { interval: 150 }, function (monitor) {
    monitor.on("created", function (f, stat) {
        compile(f);
    })
    monitor.on("changed", function (f, curr, prev) {
        compile(f);
    })
    monitor.on("removed", function (f, stat) {
        console.log('removed ' + f);
    })
})

function compile(f) {
    var parts = f.split('.');
    var suffix = parts[parts.length - 1];
    if (suffix === 'html') {
        var html = fs.readFile(f, 'utf8', function (err, data) {
            if (err) {
                return console.log(err);
            }
            var newFile;
            if (outDir == '') {
                newFile = f.replace(".html", ".js");
            }
            else {
                var newFileName = getFileName(f);
                newFile = outDir + '\\' + newFileName.replace(".html", ".js")
            }
            var line = 'handlebars.cmd ' + f + " -f " + newFile;
            console.log(line);
            cmd.stdin.write(line + '\n');
            cmd.on('exit', function (code) {
                console.log('Child process exited with exit code ' + code);
            });
        });
    }
}

function stripTrailingSlash(str) {
    if(str.substr(-1) == '/') {
        return str.substr(0, str.length - 1);
    }
    return str;
}

function getFileName(f) {
    return f.replace(/^.*[\\\/]/, '');
}