rhino-handlebars-precompiler.js

importPackage(java.io);

(function(args) {
    var templateFileExtension = 'handlebars',
    output = ['// This file is auto-generated and should be ignored from version control.\n'],
    console = {
        log: print
    },
    showUsage = function() {
      console.log('Usage: java -jar <rhino.jar> rhino-handlebars-compiler.js --handlebars <handlebars library path> --templates <templates directory> --output <output file>');
    },
    handlebarsLibrary,
    templatesDirectory,
    outputFile,
    templateFiles,
    outStream,
    index,
    templateFile,
    templateContents,
    argumentsParser,
    options;

    argumentsParser = function() {
        var arg, parse = function(args) {
            var options = {};
            args = Array.prototype.slice.call(args);
            arg = args.shift();
            while (arg) {
                if (arg.indexOf("--") === 0) {
                    options[arg.substring(2)] = args.shift();
                }
                arg = args.shift();
            }
            return options;
        };

        return { parse: parse };
    };

    options = new argumentsParser().parse(args);
    handlebarsLibrary = options.handlebars;
    templatesDirectory = options.templates;
    outputFile = options.output;

    templateFiles = new File(templatesDirectory).listFiles();
    outStream = new BufferedWriter(new FileWriter(outputFile));

    if (undefined === handlebarsLibrary || undefined === templatesDirectory) {
        showUsage();
        java.lang.System.exit(1);
    }
    load(handlebarsLibrary);

    output.push('(function(){');
    output.push('\n  var template = Handlebars.template, templates = Handlebars.templates = Handlebars.templates || {};\n');

    templateFiles = templateFiles.filter(function(fileName) {
        return(fileName.getName().substr(-templateFileExtension.length-1) === ("." + templateFileExtension));
    });

    for (index = 0; index < templateFiles.length; index++) {
        templateFile = templateFiles[index];
        templateName = templateFile.getName().replaceAll(('\\.' + templateFileExtension + '$'), '');
        templateContents = Handlebars.precompile(readFile(templateFile.getAbsolutePath()));
        output.push('  templates[\'' + templateName + '\'] = template(' + templateContents + ');\n');
    }

    output.push('}());');

    outStream.write(output.join(''));
    outStream.close();
}(arguments));

I fixed the filter to support other template file extensions such as .html and .mustache.