javascript - 使用 `Promise.resolve` 订购多功能

Question

我有 3 个函数，每个函数都单独使用 Promise.resolve，
如何使用 Promise.resolve For All？，当我调用所有函数时，这些函数没有排序

function sendAllText(msg, opts) {
   if (locale.keyboards[msg.text].text) {
      var i,j,tempstring, promise;
      promise = Promise.resolve();
      for (i=0,j=locale.keyboards[msg.text].text.length; i<j; i++) {
          tempstring = locale.keyboards[msg.text].text[i];
          promise = promise.then(bot.sendMessage.bind(bot,msg.chat.id, tempstring, opts));
      }
   }
}
function sendAllPhoto(msg, opts) {
   if (locale.keyboards[msg.text].photo) {
      var i,j,tempstring, promise;
      promise = Promise.resolve();
      for (i=0,j=locale.keyboards[msg.text].photo.length; i<j; i++) {
          tempstring = locale.keyboards[msg.text].photo[i];
          promise = promise.then(bot.sendPhoto.bind(bot,msg.chat.id, tempstring, opts));
      }
   }
}

function sendAllVideo(msg, opts) {
   if (locale.keyboards[msg.text].video) {
      var i,j,tempstring, promise;
      promise = Promise.resolve();
      for (i=0,j=locale.keyboards[msg.text].video.length; i<j; i++) {
          tempstring = locale.keyboards[msg.text].video[i];
          promise = promise.then(bot.sendVideo.bind(bot,msg.chat.id, tempstring, opts));
      }
   }
}

当我调用函数时，我的数据未排序，我正在使用 Node telegram bot Api

bot.onText(/\/love/, function onLoveText(msg) {
  const opts = {
    reply_to_message_id: msg.message_id,
    reply_markup: JSON.stringify({
      keyboard: [
        ['Yes, you are the bot of my life ❤'],
        ['No, sorry there is another one...']
      ]
    })
  };
  sendAllText(msg, opts);
  sendAllPhoto(msg, opts);
  sendAllVideo(msg, opts); 
});

Answer 1

在三个函数的末尾，在它们的循环之后，添加:

return promise;

还要确保在函数开头定义 Promise 变量，这样当 if 条件不成立时也会定义它。

例如，在第一个函数中:

function sendAllText(msg, opts) {
   var promise = Promise.resolve(); // <----
   if (locale.keyboards[msg.text].text) {
      var i,j,tempstring;
      for (i=0,j=locale.keyboards[msg.text].text.length; i<j; i++) {
          tempstring = locale.keyboards[msg.text].text[i];
          promise = promise.then(bot.sendMessage.bind(bot,msg.chat.id, tempstring, opts));
      }
   }
   return promise; // <-----
}

然后在最后一段代码中，链接你的 promise :

sendAllText(msg, opts)
    .then(sendAllPhoto.bind(null, msg, opts))
    .then(sendAllVideo.bind(null, msg, opts));