Fehler beim Datei-Upload in Express.js mit Multer

Question

Ich lerne Node.js aus einem Buch "Web-Entwicklung mit Nodejs und MongoDB" und ist fest an einem Punkt, wo ich ein Bild mit Multer hochladen muss. Der Kodex geht so: -

Below My configure.js Datei ist:

var path = require('path'), 
routes = require('./routes'), 
exphbs = require('express-handlebars'), 
express = require('express'), 
bodyParser = require('body-parser'), 
cookieParser = require('cookie-parser'), 
morgan = require('morgan'), 
methodOverride = require('method-override'), 
errorHandler = require('errorhandler'); 
multer = require('multer'); 
moment = require('moment'); 
var upload = multer({ dest: './public/upload/temp' }); 
module.exports = function(app) { 
app.use(morgan('dev')); 
app.use(methodOverride()); 
app.use(cookieParser('some-secret-value-here')); 
routes(app); 

app.post('/public/upload/temp', upload.single('img'), function(req, res) { 
    //var form_description = req.body.description; 
    console.log(req.file.name); 
    // insert operations into database get placed here 
    res.redirect('/'); 
}); 

app.use('/public/', express.static(path.join(__dirname, 
    '../public'))); 

if ('development' === app.get('env')) { 
    app.use(errorHandler()); 
} 

app.engine('handlebars', exphbs.create({ 
    defaultLayout: 'main', 
    layoutsDir: app.get('views') + '/layouts', 
    partialsDir: app.get('views') + '/partials', 
    helpers: { 
     timeago: function(timestamp) { 
      return moment(timestamp).startOf('minute').fromNow(); 
     } 
    } 
}).engine); 
return app; 
}; 

Unten ist die Lenker Datei oder (HTML-Datei): -

<div class="panel panel-primary"> 
<div class="panel-heading"> 
<h3 class="panel-title"> 
Upload an Image 
</h3> 
</div> 
<form method="post" action="/images" enctype="multipart/formdata"> 
<div class="panel-body form-horizontal"> 
<div class="form-group col-md-12"> 
<label class="col-sm-2 control-label" for="file">Browse:</label> 
<div class="col-md-10"> 
<input class="form-control" type="file" name="file" id="file"> 
</div> 
</div> 
<div class="form-group col-md-12"> 
<label class="col-md-2 control-label" for="title">Title:</label> 
<div class="col-md-10"> 
<input class="form-control" type="text" name="title"> 
</div> 
</div> 
<div class="form-group col-md-12"> 
<label class="col-md-2 control-label" for="description">Description 
</label> 
<div class="col-md-10"> 
<textarea class="form-control" name="description" rows="2"></textarea> 
</div> 
</div> 
<div class="form-group col-md-12"> 
<div class="col-md-12 text-right"> 
<button type="submit" id="login-btn" 
class="btn btn-success" type="button"> 
<i class="fa fa-cloud-upload "> 
</i> Upload Image</button> 
</div> 
</div> 
</div> 
</form> 
</div> 
<div class="panel panel-default"> 
<div class="panel-heading"> 
<h3 class="panel-title"> 
</h3> 
</div> 
<div class="panel-body"> 
{{#each images}} 
<div class="col-md-4 text-center" style="padding-bottom:1em;"> 
<a href="/images/{{ uniqueId }}"> 
<img src="/public/upload/{{filename}}" alt="{{title}}" style="width: 
175px; height: 175px;" class="imgthumbnail"> 
</a></div> 
{{/each}} 
</div> 
</div> 

Unter dem Bild ist .js Controller Datei: -

var fs = require('fs'); 
var path = require('path'); 
module.exports = { 
index: function(req, res) { 
    var viewModel = { 
     image: { 
      uniqueId: 1, 
      title: 'Sample Image 1', 
      description: 'This is a sample.', 
      filename: 'sample1.jpg', 
      views: 0, 
      likes: 0, 
      timestamp: Date.now 
     }, 
     comments: [{ 
      image_id: 1, 
      email: 'test@testing.com', 
      name: 'Test Tester', 
      gravatar: 'http://lorempixel.com/75/75/animals/1', 
      comment: 'This is a test comment...', 
      timestamp: Date.now 
     }, { 
      image_id: 1, 
      email: 'test@testing.com', 
      name: 'Test Tester', 
      gravatar: 'http://lorempixel.com/75/75/animals/2', 
      comment: 'Another followup comment!', 
      timestamp: Date.now 
     }] 
    }; 
    res.render('image.handlebars', viewModel); 
}, 
create: function(req, res) { 
    var possible = 'abcdefghijklmnopqrstuvwxyz', 
     imgUrl = ''; 
    for (var i = 0; i < 6; i += 1) { 
     imgUrl += possible.charAt(Math.floor(Math.random() * 
      possible.length)); 
    } 
    var tempPath = req.file.path, 
     ext = path.extname(req.file.name).toLowerCase(), 
     targetPath = path.resolve('./public/upload/' + imgUrl + ext); 
    if (ext === '.png' || ext === '.jpg' || ext === '.jpeg' || ext === 
     '.gif') { 
     fs.rename(tempPath, targetPath, function(err) { 
      if (err) throw err; 
      res.redirect('/images/' + imgUrl); 
     }); 
    } else { 
     fs.unlink(tempPath, function() { 
      if (err) throw err; 
      res.json(500, { error: 'Only image files are allowed.' }); 
     }); 
    } 
}, 
like: function(req, res) { 
    res.send('The image:like POST controller'); 
}, 
comment: function(req, res) { 
    res.send('The image:comment POST controller'); 
} 
}; 

Wenn der Server ausgeführt wird und besuchen Sie die Website auf localhost und versuchen, ein Bild zu, indem Sie auf diesem Fehler kommt auf Bild hochladen Taste: -

Kann nicht Eigenschaft ‚Pfad‘ undefinierter

at create (G:\Docs\Node.js\Project\imgploader.io\controllers\image.js:40:32) 
at Layer.handle [as handle_request] (G:\Docs\Node.js\Project\imgploader.io\node_modules\express\lib\router\layer.js:95:5) 
at next (G:\Docs\Node.js\Project\imgploader.io\node_modules\express\lib\router\route.js:137:13) 
at Route.dispatch (G:\Docs\Node.js\Project\imgploader.io\node_modules\express\lib\router\route.js:112:3) 
at Layer.handle [as handle_request] (G:\Docs\Node.js\Project\imgploader.io\node_modules\express\lib\router\layer.js:95:5) 
at G:\Docs\Node.js\Project\imgploader.io\node_modules\express\lib\router\index.js:281:22 
at Function.process_params (G:\Docs\Node.js\Project\imgploader.io\node_modules\express\lib\router\index.js:335:12) 
at next (G:\Docs\Node.js\Project\imgploader.io\node_modules\express\lib\router\index.js:275:10) 
at Function.handle (G:\Docs\Node.js\Project\imgploader.io\node_modules\express\lib\router\index.js:174:3) 
at router (G:\Docs\Node.js\Project\imgploader.io\node_modules\express\lib\router\index.js:47:12) 

Was ist das Problem lesen? Ich habe alles im Internet ausprobiert aber trotzdem das selbe! Bitte Hilfe

Answer 1

Vielleicht, weil Sie verwendet haben (;) am Ende der Fehlerbehandlungs Erklärung

errorHandler = require('errorhandler'); 

auch in Ihrem HTML-Attribut name sollte, wie Sie es multer verwendet werden img.