3

下午好，

我最近开始使用 Node.js + Express + MongoDB。我设置了一个简单的应用程序，其中包含：

/**
 * Module dependencies.
 */

var express = require('express')
  , routes = require('./routes')
  , mongoose = require('mongoose')
  , models = require('./models')
  , Document
  , db;

// lots of conf ...

models.defineModels(mongoose, function() {
  app.Document = Document = mongoose.model('Document');
  db = mongoose.connect(app.set('db-uri'));
})

// Routes

app.get('/', routes.home);
app.get('/documents.:format?', routes.list);

// classical end of app.js

我在“routes”文件夹中也有一个相应的“index.js”文件，其中包含：

exports.home = function(req, res){
  res.render('index', { title: 'Indx' })
};

exports.list = function(req, res){
    Document.find().all(function(documents) {
        switch (req.params.format) {
            case 'json':
                res.send(documents.map(function(d) {
                    return d.__doc;
                }));
            break;
            default:
                res.render('index', { title: 'Indx' });
        }
    });
};

路由部分没问题，这意味着当我将浏览器指向 localhost:3000 时，我会看到（生成的 Jade 模板）“索引”视图。当我指向 localhost:3000/documents 时，路由工作正常，并且代码正在尝试为我的“index.js”路由的“列表”部分提供服务。但是，我希望我在主应用程序中创建的“文档”猫鼬模型能够在“index.js”中被识别，但显然情况并非如此，因为我不断收到以下错误：

Express
500 ReferenceError: Document is not defined
at C:\PERSO\DEV\indxjs\routes\index.js:23:2
at callbacks (C:\PERSO\DEV\indxjs\node_modules\express\lib\router\index.js:272:11)
at param (C:\PERSO\DEV\indxjs\node_modules\express\lib\router\index.js:246:11)
at param (C:\PERSO\DEV\indxjs\node_modules\express\lib\router\index.js:243:11)
at pass (C:\PERSO\DEV\indxjs\node_modules\express\lib\router\index.js:253:5)
at Router._dispatch (C:\PERSO\DEV\indxjs\node_modules\express\lib\router\index.js:280:4)
at Object.handle (C:\PERSO\DEV\indxjs\node_modules\express\lib\router\index.js:45:10)
at next (C:\PERSO\DEV\indxjs\node_modules\express\node_modules\connect\lib\http.js:204:15)
at Object.methodOverride [as handle] (C:\PERSO\DEV\indxjs\node_modules\express\node_modules\connect\lib\middleware\methodOverride.js:35:5)
at next (C:\PERSO\DEV\indxjs\node_modules\express\node_modules\connect\lib\http.js:204:15)

I could obviously define my routing from within the 'app.js' with something like :

app.get('/documents.:format?', loadUser, function(req, res) {
    // ...
}

But can anyone see a way of talking with mongoose while retaining the elegant './routes/index.js' separation from the 'app.js' ?

Thanks a lot

EDIT : following kind answer from Wes, I added the following code to 'index.js':

var Document;
function defineRoutes(mongoose, fn) {
  Document = mongoose.model('Document');
  fn();
}
exports.defineRoutes = defineRoutes;
// then the same as in initial post

And I enclosed the routing definitions within this function in 'app.js' :

routes.defineRoutes(mongoose, function() {
  app.get('/', routes.home);
  app.get('/documents.:format?', routes.list);
})

Everything is ok when I point to localhost:3000, but when I point to /documents, the browser keeps loading, loading ...

4

2 回答 2

2

Thanks to Wes Johnson, I found my way out. I was blindly following a dated tutorial, which used deprecated methods from MongoDb. Below is the code snippet I finally used to implement the 'list documents' feature:

exports.list = function(req, res){
    Document.find({},function(err, documents) {
        switch (req.params.format) {
            case 'json':
                res.send(documents.map(function(d) {
                    return d.toObject();
                }));
            break;
            default:
                res.render('index', { title: 'Indx' });
        }
    });
};

Once again, thanks Wes !

于 2012-06-09T12:40:58.237 回答
1

Node modules are self-contained in terms of variable scope. Your Document object is not accessible from index.js as you mention. You need to pass this along to your routes logic, or pass along mongoose itself.

require calls are cached for the most part, so requiring mongoose in your index.js file and getting an instance of Document there is one option.

Since you don't really use Document in your app.js, you could always move the db configuration to another module and export the important references back to the scripts that need them.

于 2012-06-08T16:39:50.257 回答