node_delegate_example.js

exports.deliver = function (webroot, req, res) {
  var
    stream,
    fpRes = exports.filepath(webroot, url.parse(req.url).pathname),
    fpErr = fpRes[0],
    filepath = fpRes[1],
    errorCallback,
    headerFields = {},
    addHeaderCallback,
    delegate = {
      error: function (callback) {
        errorCallback = callback;
        return delegate;
      },
      //...Setup the other callbacks...
    };
    
  process.nextTick(function() {
    //If file is in a directory outside of the webroot, deny the request
    if (fpErr) {
      //... omitted for brevity...
    }
    else {
      fs.stat(filepath, function (err, stat) {
        if( (err || !stat.isFile())) {
          var exactErr = err || 'File not found';
          if (beforeCallback)
            beforeCallback();
          if (otherwiseCallback)
            otherwiseCallback(exactErr);
        } else {
          stream = exports.streamFile(filepath, headerFields, stat, res, req)
          //... omitted for brevity ...
          if(errorCallback){
            stream.addListener("error", errorCallback);
          }
        }
      });
    }
  });
  
  return delegate;
};