Question

我试图创建一个机器人，每当AskReddit帖子发布到Reddit时都会向我发送通知。我有这个应用程序每2秒在Heroku上轮询Reddit。

问题

每次有新帖子时，都会向我发送一封电子邮件。应该发生的事情是新帖子应该被缓存，直到在Reddit上发布一个新帖子。相反，当发布新帖子时，电子邮件会每两秒发送一次;重复播放与之前相同的电子邮件，直到发布新帖子。

我尝试了什么

我已经尝试创建一个名为latestCache的缓存变量，如下所示，可以缓存上一篇文章。我也尝试过每5秒减慢一次API调用。两个都没有工作。

任何人都知道我哪里出错了？

'use strict';

const snoostorm = require('snoostorm');
const snoowrap = require('snoowrap');
const nodemailer = require('nodemailer');

// NOTE: The following examples illustrate how to use snoowrap. However, hardcoding
// credentials directly into your source code is generally a bad idea in practice (especially
// if you're also making your source code public). Instead, it's better to either (a) use a separate
// config file that isn't committed into version control, or (b) use environment variables.

// Alternatively, just pass in a username and password for script-type apps.
const r = new snoowrap({
    userAgent: 'NodeJS',
    clientId: '******',
    clientSecret: '*****',
    username: '******',
    password: '******'
});

var latestCache;

var client = new snoostorm(new snoowrap(r));


var transporter = nodemailer.createTransport('smtps://******@gmail.com:******@smtp.gmail.com');


var submissionStream = client.SubmissionStream({
    "subreddit": "AskReddit",
    "results": 1
});

submissionStream.on("submission", function(post) {
    if(post.title != latestCache.title){
        latestCache = post;

            var mailOptions = {
                from: '"Test message" <test@test.com>', // sender address
                to: '******@gmail.com', // list of receivers
                subject: 'Reddit post', // Subject line
                html: '' +
                '<table width="600" align="center" cellpadding="0" cellspacing="0">' +
                '<tr><td colspan="2"><h1>New Reddit AskReddit post from ' + post.author.name + '</h1></td></tr>' +
                '<tr><td><strong>Post Link</strong></td><td> <a href="' + post.url + '">Post Link</a></td></tr>' +
                '<tr><td>&nbsp;</td><td> <a href="http://www.reddit.com/message/compose?to=' + post.author.name + '&subject=Response+to+loan+request">Reply to loan request</a></td></tr>' +
                '</table>'
            };

            // send mail with defined transport object
            transporter.sendMail(mailOptions, function (error, info) {
                if (error) {
                    return console.log(error);
                }
                console.log('Message sent: ' + info.response);
            });
    }
});

Answer 1

我会

保留超过1个帖子的缓存，最高可达10-20。这样它就可以每隔一定时间大量发送。

将新帖子推送到缓存中，并触发单独的sendMail函数

const { throttle } = require('lodash')

let posts = []

submissionStream.on("submission", function(post) {
  posts.push({post})
  sendMail()
})

const sendMail = throttle(() => {
  // send mail here
  transporter.sendMail({
    subject: `${posts.length} new posts submitted`
  })
  // Either clear the cache
  posts = []
}, 2000)

我不确定submissionStream API是如何运作的，但如果您说它是

重复相同的电子邮件

然后我只是将过去的帖子标记为sent，而不是完全清除缓存并过滤掉未发送的帖子并发送这些帖子。
```
const sendMail = throttle(() => {

  const postsToBeSent = posts.filter(p => !p.sent)

  transporter.sendMail({
    // ...
  })

  postsToBeSent.forEach(p => p.sent = true)

}, 2000)
```

节点cron作业在缓存后每2秒发送一次电子邮件

1 个答案: