在Express JS中使用Multer基于扩展名过滤文件 [英] Filter files on the basis of extension using Multer in Express JS

问题描述

正如问题标题所述，我需要根据文件扩展名过滤上传的文件.因此，我浏览了官方文档并搜索了该网站.

As question title explains, I need to filter uploaded files on the basis of file extension. So, I went through the official docs and searched this website.

我尝试过的事情

我尝试了遇到的解决方案.文件已成功上传，但问题是如何过滤文件.目前，我的Router.js文件如下所示.

I've tried solutions I came across. Files are being successfully uploaded, but the problem is how to filter files. Currently my Router.js file looks like this.

Router.JS

Router.JS

var multer  = require('multer');
var storage = multer.diskStorage({ //multers disk storage settings
    destination: function (req, file, cb) {
        cb(null, './public/uploads/')
    },
    limits:{
        files: 1,
        fileSize: 1024 * 1024
    },
    filename: function (req, file, cb) {
        var datetimestamp = Date.now();
        cb(null, file.fieldname + '-' + datetimestamp + '.' + file.originalname.split('.')[file.originalname.split('.').length -1])
    },
    onFileUploadStart: function(file) {
        console.log("Inside uploads");
        if (file.mimetype == 'image/jpg' || file.mimetype == 'image/jpeg' || file.mimetype == 'image/png') {
            return true;
        }
        else
        {
            return false;
        }
    }
});
var upload = multer({ //multer settings
    storage: storage
}).single('profilepic');


router.post('/profile', function(req, res){
    upload(req,res,function(err){
        if(err)
        {
            console.log(err);
        }
        else
        {
            console.log("Image was uploaded");
        }
    });
});

我尝试在onFileUploadStart中回显某些内容，以检查它是否正在进入该功能.事实并非如此.除了onFileUploadStart之外，我还尝试过fileFilter，如该链接所述.没有帮助.有什么建议如何解决这个问题?预先感谢.

I tried echoing something in onFileUploadStart to check if it is going into that function or not. And it was not. Besides onFileUploadStart, I also tried fileFilter as mentioned at this link, but it was not helpful. Any suggestions how to solve this? Thanks in advance.

推荐答案

使用multer的示例:

var storage = multer.diskStorage({ //multers disk storage settings
    destination: function (req, file, cb) {
        cb(null, './public/uploads/')
    },
    filename: function (req, file, cb) {
        var datetimestamp = Date.now();
        cb(null, file.fieldname + '-' + datetimestamp + '.' + file.originalname.split('.')[file.originalname.split('.').length -1])
    }
});

var upload = multer({ //multer settings
    storage: storage,
    fileFilter: function (req, file, callback) {
        var ext = path.extname(file.originalname);
        if(ext !== '.png' && ext !== '.jpg' && ext !== '.gif' && ext !== '.jpeg') {
            return callback(new Error('Only images are allowed'))
        }
        callback(null, true)
    },
    limits:{
        fileSize: 1024 * 1024
    }
}).single('profilepic');

摘录自 Iceman 和米哈伊尔(Mikhail).归属详细信息可以在贡献者页面上找到.来源已获得 CC BY-SA 3.0 的许可，并且可以在文档存档.参考主题ID:4080，示例ID:14210.

Excerpted from Node.js - File upload. The original authors were Iceman and Mikhail. Attribution details can be found on the contributor page. The source is licenced under CC BY-SA 3.0 and may be found in the Documentation archive. Reference topic ID: 4080 and example ID: 14210.

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