如何使用node.js / Express 3和Mongoose（MongoDB）来组织代码/逻辑

Question

I see lots of examples where node.js / express router code is organized like this:

// server.js

var cats = require('cats');
app.get('/cats', cats.findAll);

// routes/cats.js

exports.findAll = function(req, res) {
    // Lookup all the cats in Mongoose CatModel.
};

I'm curious if it would be okay to put the logic to create, read, update and delete cats in the mongoose CatModel as methods? So you could do something like cat.findAll(); The model might look something like this:

var Cat = new Schema({
   name: {
     type: String,
     required: true
   }
});

Cat.methods.findAll = function(callback) {
   // find all cats.
   callback(results);
}

Then you could use this in your router:

app.get('/cats', cats.findAll);

If if further logic / abstraction is needed (to process the results) then one could do it in routes/cats.js .

Thanks in Advance.

Answer 1

Obviously your architecture is completely up to you. I've found that separating my routes (which handle business logic) and models (which interact with the db) is necessary and very easy.

So I would usually have something like

app.js

var cats = require ('./routes/cats');
app.get('/api/cats', cats.getCats);

routes/cats.js

var Cats = require ('../lib/Cats');

exports.getCats = function (req, res, next) {
  Cat.get (req.query, function (err, cats) {
  if (err) return next (err);
  return res.send ({
    status: "200",
    responseType: "array",
    response: cats
    });
  });
};

lib/Cat.js

var catSchema = new Schema({
   name: {
     type: String,
     required: true
   }
});

var Cat = mongoose.model ('Cat', catSchema);

module.exports = Cat;

Cat.get = function (params, cb) {
  var query = Cat.find (params);
  query.exec (function (err, cats) {
    if (err) return cb (err);
    cb (undefined, cats);
  });
};

So this example doesn't exactly show an advantage, but if you had an addCat route, then the route could use a "getCatById" function call, verify the cat doesn't exist, and add it. It also helps with some nesting. The routes could also be used for sanitizing the objects before sending them off, and might also send resources and information used in UI that isn't necessarily coupled with mongoose. It also allows interactions with the database to be reusable in multiple routes.