Firestore 通过函数将文档 ID 添加到数据

Question

I'm looking to add the Firestore ID to the DocumentData, so that I can easily utilize the ID when referring to rows in a table, without having to use document.data().property everytime I call a property of a document. Instead, I want to be able to call document.id.... document.property... and so on.

Is there an easy way to do this? Possibly with a Cloud Function that adds the auto-generated ID to the document data?

Thanks!

---

Example:

export const getSpaces = async () => {
  const spaceDocs = await getDocs(spacesCollection)
  spaceDocs.docs.forEach((spaceDoc) => {
    const spaceID = spaceDoc.id
    const spaceData = spaceDoc.data()
    console.log(spaceID)
    
    spaces.value.push(spaceData)
  })
}

Now, the spaces array has objects containing the data of the documents. But, I loose the ability to reference the ID of a document.

Alternatively, I can add the entire document to the array, but following that, I'll have to access the properties by always including the data() in between. Ie space.data().name

I'm certain, theres a better way

Answer 1

A DocumentSnapshot has id property that you are looking for. If you add something within the document, then you'll need to access the data first with doc.data().field_name .

Answer 2

You don't need Cloud Functions to add the document ID to the data of that document. If you look at the third code snippet in the documentation on adding a document , you can see how to get the ID before writing the document.

In some cases, it can be useful to create a document reference with an auto-generated ID, then use the reference later. For this use case, you can call doc() [without any arguments]:

const newCityRef = db.collection('cities').doc(); // 👈 Generates a reference, but doesn't write yet

// Later...
const res = await newCityRef.set({
  newCityRef.id, // 👈 Writes the document ID
  // ...
});

---

As others have commented, you don't need to store the ID in the document. You can also add it to your data when you read the documents, with:

spaceDocs.docs.forEach((spaceDoc) => {
  const spaceID = spaceDoc.id
  const spaceData = spaceDoc.data()
  console.log(spaceID)
  
  spaces.value.push({ id: spaceID, ...spaceData })
})

With this change your spaces contains both the document ID and the data of each document.

Answer 3

Working on another problem, I came across the solution. Quite simple actually:

When declaring the new Object, you can add ...doc.data() to add all the properties of the DocumentData to the newly created Object, after initialising it with an id. This works for me anyways. Case closed.

onSnapshot(profilesCollectionRef, (querySnapshot) => {
  const profilesHolder = [];
  querySnapshot.forEach((doc) => {
    const profile = {
      id: doc.id,
      ...doc.data(),
    }
    profilesHolder.push(profile);
    console.log(profile);
  });
            
  profiles.value = profilesHolder;
});
    
onSnapshot(doc(db, "profiles", userId), (doc) => {
  const newProfile = {
    id: doc.id,
    ...doc.data(),
  }
  myProfile.value = newProfile as Profile;
});