我已经制作了一个nodejs脚本来将CSS文件上传到我们的Web应用程序。我已经省略了所有不必要的内容:

var downloadCSS = function() {
  var download = wget.download(src, output, options);
  download.on('end', function(outputMessage) {
    var unzipStream = fs.createReadStream(output).pipe(unzip.Extract({ path: path }));
    unzipStream.on('close', function() {
      findFilesAsync(path);
    });
  });
}

var findFilesAsync = function(path) {
  for (var vendor in searchList) {
    (function(filePath, vendor, loginCredentials){
      glob(filePath, function(err, files) {
        login(loginCredentials, files[0], vendor);
      })
    })(filePath, vendor, loginCredentials);
  }
};

var login = function(credentials, file_local, vendor) {
  request.post(
    'https://server',
    function(error, response, body) {
      getSettings(cookie, file_local, vendor);
    }
  );
};

var getSettings = function(cookie, file_local, vendor) {
  request.get(
    'https://server',
    function(error, response, body) {
      fileUpload(cookie, settings, file_local, vendor);
    }
  );
};

var fileUpload = function(cookie, settings, file_local, vendor) {
  var CSS_file = fs.createReadStream(file_local);

  CSS_file.on('error', function(err) {
    console.log('error at reading CSS file');
  });

  request.post(
    'https://server',
    function(error, response, body) {
      setSettings(cookie, settings, vendor);
    }
  );
};

var setSettings = function(cookie, settings, vendor) {
  request.put(
    'https://server',
    function(error, response, body) {
      logout(cookie, settings, vendor);
    }
  );
};

var logout = function(cookie, settings, vendor) {
  request.get(
    'https://server',
    function(error, response, body) {
    }
  );
};


要上传一个css文件,如果没有错误,这些函数将自上而下调用:

downloadCSS()
findFilesAsync()
login()
getSettings()
fileUpload()
setSettings()
logout()


CSS文件有5个,因此只要在findFilesAsync()函数中找到文件,就会异步调用一个新的login()函数。

我知道可以凭诺言做到这一点,但是我不知道从哪里开始?

最佳答案

看看这个MDN Promise reference,他们为使用Promise的http请求提供了一个很好的示例函数。因此,为了避免回调,您将不得不更改/修改request

关于javascript - 将回调转换为Node.js中的Promise,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/36720292/

10-14 23:54
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