'variable'：function（req，res）{}是什么意思？

Question

I am currently starting with node.js, so I am for the first time using Js beyond dom manipulation.

I came across a code piece like below. I cant understand it. What is happening? is it a key value object? Is an anonymous function being passed to 'new' ?

module.exports = {

  'new': function(req, res) {
    res.view();
  },

  /**
   * Overrides for the settings in `config/controllers.js`
   * (specific to UserController)
   */
  _config: {}


};

Answer 1

As others have said, this is ultimately just creating an object called module.exports then assigning two properties to it. One is another object called _config and the other is a function called new that expects two arguments.

That's the plain JavaScript explanation.

In node.js, you're also seeing a few conventions in play, which I'll describe below.

---

One convention is module.exports .

This is the object that will be made available when some other code loads this file using require() . It would work something like this:

var m = require('yourmodule.js');
m.new(req, res);

---

Another convention is the pair of arguments: req, res .

These are usually parameters that represent a request (like an http.IncomingMessage ) and a response (like a http.ServerResponse ).

---

Putting it all together, this module is probably defining a Controller that will receive http requests, and render them as responses. It currently does this for new , and there are probably routes configured elsewhere that call this method when a user requests something like ' http://server.come/user/new '.

Answer 2

Looks like basic JavaScript.

An object named module has a property named exports that is an object.

This object has a property named new whose value is an anonymous function.

In theory you could invoke the method like this:

module.exports.new(someRequest, someResponse);