Question

我遇到了Nodejs的问题，导航到我的localhost：3000 / survey时收到错误信息。我遵循了一个广泛的教程，尽管通过stackoverflow搜索答案，我无法确定错误的原因，根据教程，一切都应该正常工作。当我导航到localhost：3000 / users时，它工作得非常好。我的路由文件users.js根据需要使用资源进行响应，我只是无法使localhost：3000 / survey工作。下面我发布了错误代码和我的调查的控制器，路线和模型。

我收到错误

Error: No default engine was specified and no extension was provided.

   at new View (/Users/testuser/WebstormProjects/test/node_modules/express/lib/view.js:62:11)
   at EventEmitter.render (/Users/testuser/WebstormProjects/test/node_modules/express/lib/application.js:569:12)
   at ServerResponse.render (/Users/testuser/WebstormProjects/test/node_modules/express/lib/response.js:961:7)
   at /Users/testuser/WebstormProjects/test/app.js:60:7
   at Layer.handle_error (/Users/testuser/WebstormProjects/test/node_modules/express/lib/router/layer.js:71:5)
   at trim_prefix (/Users/testuser/WebstormProjects/test/node_modules/express/lib/router/index.js:310:13)
   at /Users/testuser/WebstormProjects/test/node_modules/express/lib/router/index.js:280:7
   at Function.process_params (/Users/testuser/WebstormProjects/test/node_modules/express/lib/router/index.js:330:12)
   at next (/Users/testuser/WebstormProjects/test/node_modules/express/lib/router/index.js:271:10)
   at Layer.handle_error (/Users/testuser/WebstormProjects/test/node_modules/express/lib/router/layer.js:73:5)
   at trim_prefix (/Users/testuser/WebstormProjects/test/node_modules/express/lib/router/index.js:310:13)
   at /Users/testuser/WebstormProjects/test/node_modules/express/lib/router/index.js:280:7
   at Function.process_params (/Users/testuser/WebstormProjects/test/node_modules/express/lib/router/index.js:330:12)
   at next (/Users/testuser/WebstormProjects/test/node_modules/express/lib/router/index.js:271:10)
   at /Users/testuser/WebstormProjects/test/app.js:39:3
   at Layer.handle [as handle_request] (/Users/testuser/WebstormProjects/test/node_modules/express/lib/router/layer.js:95:5)

模型

var mongoose = require('mongoose');
var Schema = mongoose.Schema;

var SurveySchema = new Schema ({
created: {
    type: Date,
    default: Date.now
},
    von: Date,
    bis: Date,
    kmStart: Number,
    kmEnde: Number,
    strecke: String,
    zweck: String,
    privat: Boolean,
    fahrer: String,
    fahrzeug: String
});

SurveySchema.statics = {
load: function(id, cb){
    this.findOne({_id : id}).exec(cb);
    }
};

mongoose.model('Survey', SurveySchema);

控制器

require('../models/survey');
var mongoose = require('mongoose');
var Survey = mongoose.model("Survey");

exports.post = function(req, res){
var survey = new Survey(req.body);
survey.save();
res.jsonp(survey);
}

路线

var express = require('express');
var router = express.Router();

var surveys = require('../controllers/surveysController');

/* POST /surveys */
router.post('/', surveys.post);

module.exports = router;

Answer 1

@all我只是想说我确实解决了这个问题。我想是因为我在app.js文件中使用了错误的MongoDB。这一变化解决了这个问题。

mongoose.connect('mongodb://localhost/mydb');

要

mongoose.connect('mongodb://localhost/test');

Answer 2

你能展示你的app.js吗？让我们确保你告诉应用程序使用路由器进行/调查

Answer 3

这是app.js的要求

var express = require('express');
var path = require('path');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');

var users = require('./routes/users');
var surveys = require('./routes/surveys');

var app = express();

var mongoose = require('mongoose');

mongoose.connect('mongodb://localhost/mydb');
var db = mongoose.connection;

db.on('error', function callback(){
  console.log("connection to MongoDB failed");
});

db.once('open', function callback(){
  console.log("connection to MongoDB success");
});

// uncomment after placing your favicon in /public
//app.use(favicon(path.join(__dirname, 'public', 'favicon.ico')));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());

app.use('/users', users);
app.use('/surveys', surveys);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  var err = new Error('Not Found');
  err.status = 404;
  next(err);
});

// error handlers

// development error handler
// will print stacktrace
    if (app.get('env') === 'development') {
  app.use(function(err, req, res, next) {
    res.status(err.status || 500);
    res.render('error', {
    message: err.message,
      error: err
    });
  });
}

// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
  res.status(err.status || 500);
  res.render('error', {
    message: err.message,
    error: {}
  });
});


module.exports = app;

Answer 4

我想我可能知道这个问题，但是如果它不起作用我会调整我的答案。在您的代码中，我没有看到设置模板引擎的任何地方。你可以通过安装像Jade或Swig这样的东西来做到这一点。

npm install jade --save

然后告诉快递它就在那里。

app.set('view engine', 'jade');

然后，您可以设置将在模板中呈现的变量。

app.use(function(err, req, res, next) {
  res.status(err.status || 500);
  res.render('error', {
    message: err.message, //message will be rendered
    error: {} 
  });
});

然后是模板;使用Jade，它会将代码预处理为实际的html。因此，邮件将呈现给<h1>This is an error message</h1>

html
  head
  body
    h1= message

当然你可以写出HTML;这只是为了方便。以下是指向Jade或Swig的链接。如果您使用Swig，我可以使用两个左右花括号在页面中呈现数据。例如，

<div class="alert alert-danger" role="alert">
  Error: {{message}}
</div>

Express / Node Error没有提供扩展

4 个答案: