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我想讓我的節點JS代碼一步一步的工作，而不是異步使用Promise然後。節點JS承諾然後鏈接不順序
我首先刪除所有電子表格，然後生成它們，然後壓縮它們，然後加密zip文件，然後通過電子郵件發送zip文件，然後刪除電子表格。
//Schedules the job at a specific time
var start = schedule.scheduleJob({
hour: 19,
minute: 26,
dayOfWeek: 3
}, function() {
sendIt();
});
//Starts the Promise Chain
function sendIt() {
return deleteSpreadsheets().then(generateSpeadsheets).then(zipSpreadsheets).then(encrypt).then(sendEmail).then(deleteSpreadsheets);
}
//Deletes the current Spreadsheets in the folder
function deleteSpreadsheets() {
var promise = new Promise(function(resolve, reject) {
console.log('Deleting Spreadsheets');
var locationSpread = ['Location.xlsx'];
locationSpread.forEach(function(filename) {
if (fs.existsSync("./Spreadsheets/" + filename)) {
fs.unlink("./Spreadsheets/" + filename, (err) => {
if (err) {
console.log('Spreadsheet ' + filename + ' not found');
} else {
console.log('Spreadsheet ' + filename + ' successfully deleted');
}
});
}
});
resolve();
});
return promise;
}
//Generates the new Spreadsheets
function generateSpeadsheets() {
var promise = new Promise(function(resolve, reject) {
console.log('Generating Spreadsheets');
var locationSpread = ['Location.xlsx'];
locationSpread.forEach(function(filename) {
var query = connection.query('SELECT * from ' + filename.slice(0, -5), function(err, rows) {
var workbook = excelbuilder.createWorkbook('./Spreadsheets/', filename);
if (workbook == null) {
console.log('workbook null')
};
var sheet = workbook.createSheet(filename.slice(0, -5), 3, rows.length + 1);
if (sheet == null) {
console.log('sheet null')
};
sheet.set(1, 1, 'First Name');
sheet.set(2, 1, 'Last Name');
sheet.set(3, 1, 'Company');
for (var j = 2, z = 0; z < rows.length; j++, z++) {
sheet.set(1, j, rows[z].firstName);
sheet.set(2, j, rows[z].lastName);
sheet.set(3, j, rows[z].company);
}
workbook.save(function(err) {
console.log('workbook saved ' + (err ? 'failed' : 'ok'));
});
});
});
resolve();
});
return promise;
}
//Generates a Zip file with all the Spreadsheets
function zipSpreadsheets() {
var promise = new Promise(function(resolve, reject) {
console.log('Zipping Spreadsheets');
var zipFolder = require('zip-folder');
zipFolder('./Spreadsheets/', './Spreadsheets.zip', function(err) {
if (err) {
console.log('Failed to zip folders', err);
reject();
} else {
console.log('Successfully zipped folder');
}
});
resolve();
});
return promise;
}
//Encrypts the Spreadsheet
function encrypt() {
var promise = new Promise(function(resolve, reject) {
console.log('Encrypting');
spawn = require('child_process').spawn;
zip = spawn('zip', ['-P', 'something', 'Encrypted.zip', './Spreadsheets.zip']);
zip.on('exit', function(code) {
console.log('Finished encrypting');
resolve();
});
});
return promise;
}
//Sends the Encryped Zip as an attached in an email
function sendEmail() {
var promise = new Promise(function(resolve, reject) {
console.log("MAIL SCHEDULE RUNNING");
var transporter = nodemailer.createTransport({
service: 'Gmail',
auth: {
user: 'email', // Your email id
pass: 'password'
}
});
var content = 'something';
var mailOptions = {
from: 'email', // sender address
to: 'email', // list of receivers
subject: 'Title', // Subject line
text: content,
attachments: [{
// file on disk as an attachment
filename: 'Encrypted.zip',
path: './Encrypted.zip' // stream this file
}]
};
transporter.sendMail(mailOptions, function(error, info) {
if (error) {
console.log(error);
reject();
} else {
console.log('Message sent: ' + info.response);
resolve();
};
});
});
return promise;
}這似乎並不奏效按計劃在日誌中看到：
Deleting Spreadsheets
Generating Spreadsheets
Zipping Spreadsheets
Encrypting
**Spreadsheet Location.xlsx successfully deleted**
**Finished encrypting**
MAIL SCHEDULE RUNNING
**Successfully zipped folder**
**workbook saved ok**
Message sent: -----------------------------------------------
Deleting Spreadsheets
Spreadsheet Location.xlsx successfully deleted
下面是它應該是什麼：
Deleting Spreadsheets
**Spreadsheet Location.xlsx successfully deleted**
Generating Spreadsheets
**workbook saved ok**
Zipping Spreadsheets
**Successfully zipped folder**
Encrypting
**Finished encrypting**
MAIL SCHEDULE RUNNING
Message sent: -----------------------------------------------
Deleting Spreadsheets
Spreadsheet Location.xlsx successfully deleted
你可以立即調用resolve（）而不用等待異步操作。這不是承諾如何工作 - 你必須從異步回調中調用它。 – Bergi
您應該自行確定每個異步函數（如'unlink'，'query'，'save'等），以便您可以編寫它們，並在可以同時等待的那些循環中創建一組promise。 – Bergi