使用 Cloud Firestore 更新触发器删除 Firestore 中的文档

Question

我正在使用 Cloud Firestore 触发器。
https://firebase.google.com/docs/functions/firestore-events

我的主要目标是删除一个文档“party” 当派对上没有人时。但是，我不知道如何从 Cloud Firestore 触发器。这是我的代码：

// The Cloud Functions for Firebase SDK to create Cloud Functions and setup triggers.
const functions = require('firebase-functions');

// The Firebase Admin SDK to access Cloud Firestore.
const admin = require('firebase-admin');
admin.initializeApp();

exports.deleteOnCheckout = functions.firestore.document('/parties/{documentId}')
    .onUpdate((change, context) => {
      // Get an object representing the document
      const newValue = change.after.data();
      // ...or the previous value before this update
      const previousValue = change.before.data();

      // access a particular field as you would any JS property
      const checkedIn = newValue.checkedIn;
      console.log("Array size: " + checkedIn.length);
      //If no checked in, delete document
      if(checkedIn.length == 0){
            return //Here I want to delete the document
      }else{
          //Do nothing
          return null;
      }
    });

Answer 1

您是否尝试过change.after.ref，这是文档参考？然后你可以这样做change.after.ref.delete()。