我正在使用带有nodemailer模块的nodejs创建一个应用程序来发送邮件。
我的应用程序的流程是读取包含名称和电子邮件的列表,使用jimp(基于每个名称和电子邮件)创建png文凭文件,并通过nodemailer存储并发送每个到每个不同的邮件地址,然后完成所有操作,我想删除每个文件,但以同步方式删除所有文件,因为png文凭和发送电子邮件需要一些时间:
我的列表的语法是:
const list = [
[name1, email1@mail.com]
[name2, email2@mail.com]
[ ... ]
[namex, emailx@mail.com]
]
实际上,我想等待每封邮件的发送,因为gmail似乎在处理一次发送多封邮件时存在问题,在发送13或15封邮件后,它会显示下一个错误:
error: { Error: Data command failed: 421 4.7.0 Temporary System Problem. Try again later (10). x12sm4645987otk.1 - gsmtp
因此,为了实现这一点,我使用经典的for循环遍历列表(foreach循环以异步方式进行操作,并且不让我继续控制文凭生成),我处理了每个
的位置//Iterating over mails array
for (let i = 0; i < list.length; i++) {
// Little msg to know what is going on
console.log(`Processing address ${i} out of ${list.length}`)
const element = list[i]
// diplomaData is an object which contains data needed (such as name, course, etc) to create the diploma
diplomaData.name = element[0];
// diplomaDir is the address in which each diploma gets stored, it is returned by the generateDiploma function
diplomaDir = await generator.generateDiploma(diplomaData)
// So once the diploma is generated, I send its address to generateMailContentFunction
// it returns an object which contains text like a greeting, congratulations and of course, the diploma address
mailContent = await mailer.generateMailContent(element, diplomaDir)
// So the only thing pending is to send the email with the correspondent content
await mailer.sendMail(mailContent)
// I've commented this function because even it is declared in an async way it
// await utilities.remove(diplomaDir)
}
这是我的sendMail函数:
exports.sendMail = async (mailOptions) => {
transporter.sendMail(mailOptions, (err, info) => {
if (err) {
console.log("error: ", err);
} else {
console.log(`Mail sent succesfully!`);
}
});
}
因此,用几句话来说,我的问题是nodemailer似乎在完成循环后同时启动所有邮件(我可以确认这一点,因为在控制台中,“ Processing address ...”的日志出现在来自nodemailer,所以我只想使此过程绝对同步,有人可以帮我吗?:(
答案 0 :(得分:1)
您的sendMail函数本质上不是异步的。它启动了一个异步函数(即transporter.sendMail
),然后立即返回undefined
(因为没有return语句)。
exports.sendMail = function(mailOptions){
return new Promise(function (resolve, reject){
transporter.sendMail(mailOptions, (err, info) => {
if (err) {
console.log("error: ", err);
reject(err);
} else {
console.log(`Mail sent successfully!`);
resolve(info);
}
});
});
}
现在,当您await mailer.sendMail(mailContent)
时,将兑现承诺,实际上还有一些等待的事情。也就是说,承诺的解决或拒绝。
确保具有一个try / catch块,其中包含所有等待操作符。