javascript - GridFS/multer - 无法读取未定义的属性“文件名”

问题描述

我不是 Web 开发方面的出色专家（希望至少目前是这样），所以我的问题可能有点愚蠢。

这是我的问题：我一直在研究 Node.Js 并尝试创建一个数据库，我可以在其中上传图片，然后检索它们并通过 .ejs 文件在浏览器上显示它们。

不幸的是，在 app.js 文件中，我能够 console.logimages数组并检查filename至少一个文件，同时在 .ejs 文档上循环遍历它：

   `<% for(var i = 0; i <= images.length; i++){ %>
        <img src="<%= images[i].filename %>">
    <% } %>`

我收到此问题标题中显示的错误。

有谁知道我做错了什么？我相信我在 GridFS 或 multer 上设置了一些错误，但我不是 100% 确定。

提前感谢任何将要回复的人。

在这里，您可以找到我目前在 app.js 文件中使用的代码：

var express                         = require('express'),
    mongoose                        = require('mongoose'),
    bodyParser                      = require('body-parser'),
    methodOverride                  = require('method-override'),
    expressSanitizer                = require('express-sanitizer'),
    path                            = require('path'),
    crypto                          = require('crypto'),
    multer                          = require('multer'),
    GridFsStorage                   = require('multer-gridfs-storage'),
    Grid                            = require('gridfs-stream'),
    app                             = express();

//connect to the MongoDB database
mongoose.connect("mongodb+srv://***:*****@cluster-***-***-q5eof.mongodb.net/*****?retryWrites=true&w=majority", 
{ useNewUrlParser: true,
useUnifiedTopology: true,
useFindAndModify: false,
useCreateIndex: true});

//connect to the MongoDB database
var mongoURI = "mongodb+srv://***:*****@cluster-***-***-q5eof.mongodb.net/*****?retryWrites=true&w=majority";

var conn = mongoose.createConnection(mongoURI)

//parseing incoming request bodies in a middleware before the handlers, available under the req.body property
app.use(bodyParser.urlencoded({extended: true}));

//setting the engine to read directly the ejs files without specifying their extentions on the routes
app.set('view engine', 'ejs');

//serving images, CSS files, and JavaScript files in a directory named public:
app.use(express.static('public'));

//setting method-override to be used via '_method' text before specifying the type of method used in a form
app.use(methodOverride('_method'));

//execute express-sanitizer
app.use(expressSanitizer());

let gfs
conn.once('open', () => {
  gfs = Grid(conn.db, mongoose.mongo)
  gfs.collection('uploads')
  console.log('GRID CONNECTION SUCCESSFUL')
})

//Landing page
app.get('/', function(req, res){
    gfs.files.find().toArray(function(err, images){
        if(err){
            console.log(err)
        } else {
                images.map(function(image){
                image.isImage = true;
            });
        }
        res.render('landing', {images: images});
        console.log(images[0].filename);
    });
});

//Create storage engine
 var storage = new GridFsStorage({
  url: mongoURI,
  file: (req, file) => {
    return new Promise((resolve, reject) => {
      crypto.randomBytes(16, (err, buf) => {
        if (err) {
          return reject(err);
        }
        const filename = buf.toString('hex') + path.extname(file.originalname);
        const fileInfo = {
          filename: filename,
          bucketName: 'uploads'
        };
        resolve(fileInfo);
      });
    });
  }
});
const upload = multer({ storage });

//Upload page
app.get('/upload', function(req, res){
    res.render('upload');
});

//Sending form from upload page
app.post('/upload', upload.array('file'), function(req, res){
    res.json({file: req.files});
});

app.listen('3000', function(err){
    if(err){
        console.log(err)
    } else{
        console.log("APP CONNECTED")
    }
});

标签： javascriptnode.jsmongodbexpressejs

javascript - GridFS/multer - 无法读取未定义的属性“文件名”

问题描述

解决方案

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