使用node.js服务动态.js文件

Question

I'm searching for some kind of 'template/macro engine' for javascript files. What I need to do is serving javascript files to the browser. These javascript files are mostly static but vary in some ways.

Here's what I'm basically doing at the moment:

app.get('/api/api.js', function (req, res) {
    fs.readFile(
        path.join(__dirname, './libraries/api.js'), 
        { encoding: 'utf8' }, 
        function (err, data) {
            if (err) throw err;
            res.set('Content-Type', 'text/javascript');
            res.send(data);
    });
});

Now I need to add/replace some few lines of code within the read file before serving it to the client.

Update:

Here are some examples:

var host = 'http://mydomain.com/';
var domains = ['mydomain1.com', 'mydomain2.org'];

Yes I could use basic search and replace but I wondered if there's a more generic solution.

Answer 1

I solved it writing my own little render engine as you can see here: http://jsfiddle.net/g5PEp/

var ApiRenderer = function(fileContent) {
    var fileContent = fileContent || '';
    var data = {};

    function sourroundString(str, char) {
        char = char || '\'';
        return char + str + char;
    }

    function render() {
        var result = fileContent,
            str;
        for(var key in data) {
            var substr = '/*{{' + key + '}}*/';
            if(typeof data[key] === 'string') {
                str = sourroundString(data[key]);
            }
            if(Object.prototype.toString.call( data[key] ) === '[object Array]') {
                str = '[';
                for(var i = 0; i < data[key].length; i++) {
                    str += sourroundString(data[key][i]);
                    if(i !== data[key].length - 1) {
                        str += ',';
                    }
                }
                str += ']';
            }
            result = result.replace(substr, str);
        }
        return result;
    }

    return {
        setData: function(key, value) {
            return data[key] = value;
        },
        render: function() {
            return render();
        }
    }
};

This is working for me at the moment but I'm a bit sad that this doesn't allow me to write valid javascript code in my templates.