Meteor.setTimeout（）保存当前的“ this”对象，而不是将来的对象

Question

When I am calling to Meteor.setTimeout() meteor saves the current instance of 'this' and when time's up the funcion I called uses the old instance of this (the instance that was saved when I call Meteor.setTimeout()). How can I cause meteor to use the new instance of 'this' instead ?

// Ending question
const questionEndToLog = () => this.questionEnd(firstQuestion._id);
Meteor.setTimeout(questionEndToLog, firstQuestion.time * 1000);

questionEnd(qId) {
  const addToGameLog = () => {
    const questionEnd = new QuestionEnd({
      questionId: qId
    });
    this.gameLog = this.gameLog.concat(questionEnd);
    this.save();
    return true;
  };
  const isQuestionEndAlready = !!this.gameLog
    .filter(e => e.nameType === eventTypes.QuestionEnd)
    .find(e => e.questionId === qId);
  return isQuestionEndAlready && addToGameLog();
}

export const QuestionEnd = Class.create({
  name: eventTypes.QuestionEnd,
  fields: {
    nameType: {
      type: String,
      default() {
        return eventTypes.QuestionEnd;
      },
    },
    questionId: {
      type: String,
    },
    createdAt: {
      type: Date,
      default() {
        return new Date();
      },
    },
  },
});

this.gameLog is the oldest log (the log that was when the Meteor.setTimeout() called) instead of the new one.

Answer 1

That's not a Meteor thing. When you're using () => ... then the current this context will be bound to this function.