如何在使用 NodeJs 的 firebase 快照中使用 for 循环？

Question

I want to replicate the.forEach() method using a normal for loop. The reason is that I need to anidate multiple loops, and the.forEach() method is not giving the expected result.

For exmple, if I want to retrieve my user collection, and for each user retrieve their posts, and for each post retrieve its coments (three diferent collections, with three loops anidated) then concatenate coments for each post, and send an email to each user with their posts+comments. For this I did something like:

 const users = await usersRef.get().then(users => { users.forEach(user => { const userDocRef = firestore.collection('users').doc(user.id); postsRef.where('user', '==', userDocRef).get().then(posts => { posts.forEach(user => {...

If I use a forEach(), it gives unexpected results, I think because the exection is not linear.

Instead I want to use a for loop. But I dont know how to iterate through the snapshot:

 const users = await usersRef.get(); for(let user of users.getChildren()) {...

Answer 1

The posts is a QuerySnapshot that has a docs property that is an array of all the documents in this QuerySnapshot. Try refactoring the code as shown below:

for (const post of posts.docs) {
   console.log(post.data())
}