我是node.js的初学者，并尝试构建一个基本的待办事项列表，但不断收到错误： 无法读取undefined的属性'collection'。 有人可以解释我做错了什么以及如何让我的帖子请求有效？ 谢谢您的帮助 ！
路由/ index.js
var express = require('express');
var router = express.Router();
var ObjectId = require('mongodb').ObjectId
// Get Homepage
router.get('/', ensureAuthenticated, function(req, res){
req.db.collection('Todo').find().sort({"_id": -1}).toArray(function(err, result) {
//if (err) return console.log(err)
if (err) {
req.flash('error', err)
res.render('index', {
title: 'User List',
data: ''
})
} else {
// render to views/user/list.ejs template file
res.render('index', {
title: 'User List',
data: 'ldld'
})
}
})
})
function ensureAuthenticated(req, res, next){
if(req.isAuthenticated()){
return next();
} else {
//req.flash('error_msg','You are not logged in');
res.redirect('/users/login');
}
}
module.exports = router;
路由/ Todo.js
// list dependencies
var express = require('express');
var router = express.Router();
// add db & model dependencies
var mongoose = require('mongoose');
var Todo = require('../models/Todo');
// interpret GET /products - show product listing */
// GET intepret GET /products/edit/:id - show single product edit form */
router.get('/Todo/edit/:id', function (req, res, next) {
//store the id from the url in a variable
var id = req.params.id;
var user_id = req.cookies ?
req.cookies.user_id : undefined;
//use the product model to look up the product with this id
Todo.findById(id,user_id, function (err, product) {
if (err) {
res.send('Product ' + id + ' not found');
}
else {
res.render('edit', { Todo: Todo });
}
});
});
// POST /products/edit/:id - update selected product */
router.post('/Todo/edit/:id', function (req, res, next) {
var id = req.body.id;
var Todo = {
_id: req.body.id,
content: req.body.content,
todos : todos,
updated_at : Date.now()
};
Todo.update({ _id: id}, content, function(err) {
if (err) {
res.send('Product ' + req.body.id + ' not updated. Error: ' + err);
}
else {
res.statusCode = 302;
res.setHeader('Location', 'http://' + req.headers['host'] + '/Todo');
res.end();
}
});
});
// GET /products/add - show product input form
router.get('/Todo/create', function (req, res, next) {
res.render('add');
});
// POST /products/add - save new product
router.post('/Todo/create', function (req, res, next) {
// use the Product model to insert a new product
Todo.create({
content: req.body.content,
user_id:req.cookies.user_id,
updated_at : Date.now()
}, function (err,Todo) {
if (err) {
console.log(err);
res.render('error', { error: err }) ;
}
else {
console.log('Product saved ' + Todo);
res.render('added', {Todo: Todo.content });
}
});
});
// API GET products request handler
router.get('/api/Todo', function (req, res, next) {
Todo.find(function (err, products) {
if (err) {
res.send(err);
}
else {
res.send(Todo);
}
});
});
/* GET product delete request - : indicates id is a variable */
router.get('/Todo/delete/:id', function (req, res, next) {
//store the id from the url into a variable
var id = req.params.id;
//use our product model to delete
Todo.remove({ _id: id }, function (err,Todo) {
if (err) {
res.send('Product ' + id + ' not found');
}
else {
res.statusCode = 302;
res.setHeader('Location', 'http://' + req.headers['host'] + '/Todo');
res.end();
}
});
});
// make controller public
module.exports = router;
视图/ index.handelbars
<h2 class="page-header">Dashboard</h2>
<p> Hello {{user.name}}
<p>Welcome to your dashboard</p>
<% layout( 'layout' ) -%>
<h1 id="page-title">{{ title }}</h1>
<div id="list">
<form action="/create" method="post" accept-charset="utf-8">
<div class="item-new">
<input class="input" type="text" name="content" />
</div>
</form>
{{#each todo}}
<div class="item">
<a class="update-link" href="/edit/{{#todo._id }}" title="Update this todo item">{{todo.content}}</a>
<a class="del-btn" href="/destroy/{{ #todo._id }}>" title="Delete this todo item">Delete</a>
</div>
{{/each }}
app.js
var express = require('express');
var path = require('path');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
var exphbs = require('express-handlebars');
var expressValidator = require('express-validator');
var flash = require('connect-flash');
var session = require('express-session');
var passport = require('passport');
var LocalStrategy = require('passport-local').Strategy;
var mongo = require('mongodb');
var mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/loginapp');
var db = mongoose.connection;
var routes = require('./routes/index');
var users = require('./routes/users');
var Todo = require('./routes/Todo');
// Init App
var app = express();
// View Engine
app.set('views', path.join(__dirname, 'views'));
app.engine('handlebars', exphbs({defaultLayout:'layout'}));
app.set('view engine', 'handlebars');
// BodyParser Middleware
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
// Set Static Folder
app.use(express.static(path.join(__dirname, 'public')));
// Express Session
app.use(session({
secret: 'secret',
saveUninitialized: true,
resave: true
}));
// Passport init
app.use(passport.initialize());
app.use(passport.session());
// Express Validator
app.use(expressValidator({
errorFormatter: function(param, msg, value) {
var namespace = param.split('.')
, root = namespace.shift()
, formParam = root;
while(namespace.length) {
formParam += '[' + namespace.shift() + ']';
}
return {
param : formParam,
msg : msg,
value : value
};
}
}));
// Connect Flash
app.use(flash());
// Global Vars
app.use(function (req, res, next) {
res.locals.success_msg = req.flash('success_msg');
res.locals.error_msg = req.flash('error_msg');
res.locals.error = req.flash('error');
res.locals.user = req.user || null;
next();
});
app.use('/', routes);
app.use('/users', users);
app.use('/Todo', Todo);
// Set Port
app.set('port', (process.env.PORT || 3000));
app.listen(app.get('port'), function(){
console.log('Server started on port '+app.get('port'));
});
答案 0 :(得分：0)
在var app = express();
app.use(function (req, res, next) {
req.db = db;
next();
});
这将在所有传入请求中创建对您的猫鼬连接的引用，可通过req.db访问。