Question

我是javascript和node.js的新手，并尝试通过做一些有用的事情来学习它。所以，我想发送一封带有附件图片的电子邮件。通过发出HTTP GET请求从远程服务器检索图像，并通过nodemailer（SMTP）使用Gmail发送到电子邮件地址

By reading the docs and looking through examples，我设法发送了一封没有附件的电子邮件，但我无法弄清楚如何使用Streams发送它。我使用了以下代码，但它返回了错误，我无法修复自己并需要帮助：

var nodemailer = require('nodemailer');
var request = require('request');
var config = require('../config');
var mailer;

mailer = function (opts) {
    var transporter = nodemailer.createTransport({
        service: 'Gmail',
        auth: {
            user: config.GmailAuth.email,
            pass: config.GmailAuth.password
        }
    });

    var mailOptions = {
        from: opts.from, // sender address
        to: opts.to, // list of receivers
        subject: opts.subject, // Subject line
        html: opts.body,  // html body
        attachments: [
            {
                filename: 'screenshot.png',
                content: request(opts.imageUrl)  // <-- Error here 
            }
        ]
    };

    transporter.sendMail(mailOptions, function(error, info){
        if (error) {
            return console.log(error);
        } else {
            console.log('Message sent: ' + info.response);
        }
    });
}

mailer({
        from: config.GmailAuth.email,
        to: config.sendToAddress, 
        subject: 'TEST SUBJECT',
        body: 'TEST MESSAGE BODY',
        imageUrl: 'URL_to_an_image_for_HTTP_GET_request'
       });

发生以下错误：

stream.js:74
      throw er; // Unhandled stream error in pipe.
      ^

Error: write after end
    at writeAfterEnd (_stream_writable.js:159:12)
    at Encoder.Writable.write (_stream_writable.js:204:5)
    at Encoder.Writable.end (_stream_writable.js:433:10)
    at Request.<anonymous> (C:\Users\user\Desktop\graphite_monitor\node_modules\
buildmail\src\buildmail.js:573:35)
    at Request.g (events.js:260:16)
    at emitOne (events.js:82:20)
    at Request.emit (events.js:169:7)
    at Request.onRequestError (C:\Users\user\Desktop\graphite_monitor\node_modul
es\request\request.js:820:8)
    at emitOne (events.js:77:13)
    at ClientRequest.emit (events.js:169:7)

问题是什么，我该如何解决？

Answer 1

尝试更改此内容：

attachments: [
  {
    filename: 'screenshot.png',
    content: request(opts.imageUrl)  // <-- Error here 
  }
]

为：

attachments: [
  {
    filename: "pin-marker.png",
    path: "http://img.mapeando.net/map/pin-marker.png", // <-- should be path instead of content
    cid: "pin-marker.png"
  }
]

Answer 2

我设法使用PassThrough Streams（here is somewhat similar question）使其工作，这是工作代码（在我的初始代码中需要添加更改）：

var PassThrough = require('stream').PassThrough;

var nameOfAttachment = 'screenshot.png';
var imageUrlStream = new PassThrough();
request
     .get({
             proxy: 'http://YOUR_DOMAIN_NAME:3129', // if needed
             url: opts.imageUrl
         })
     .on('error', function(err) {
             // I should consider adding additional logic for handling errors here
             console.log(err);
    })
     .pipe(imageUrlStream);

var mailOptions = {
    from: opts.from, // sender address
    to: opts.to, // list of receivers
    subject: opts.subject, // Subject line
    html: opts.body, // html body
    attachments: [
        {
            filename: nameOfAttachment,
            content: imageUrlStream
        }
    ]
};

我希望它能帮助其他初学者

如何使用node.js中的nodemailer和请求模块将图像附加到URL中的电子邮件？

2 个答案: