Is there a way to update a collectionGroup in cloud function

Question

I'm building a chat app. When a user makes an update on their local profile I'd like to use cloud functions to make that update across a collectionGroup.

I'm successfully listening to the update in cloud functions and retrieving a list of collectionGroups with the following:

        const collectionGroupNameref = await db.collectionGroup('collectionGroupName').where('userId', '==', data.uid).get();


collectionGroupNameref.forEach(async (val: any) => {
            const connectionsRef = await db.collection('collectionGroupName').doc(val.id).get();
 
        });

But now I need to update a field within that collectionGroup and that's where I'm running into issues.

The collectionGroup is stored in 2 locations:

users{id}collectionGroupName{id}
groups{id}collectionGroupName{id}

Is it possible to update all of the documents in that collectionGroup

Answer 1

There is another approach you can use :

1- Get All objects in a collection group that you want to update (v1)

export const getAllItemsFromCollectionGroup = async <T>(collection: string): Promise<T[]> => {
  const items: T[] = [];
  const db = admin.firestore();
  const query = await db.collectionGroup(collection).get();
  if (query && !query.empty) {
    query.docs.forEach(doc => {
      items.push({
        ...doc.data() as T,
        id: doc.id,
        path: doc.ref.path
      });
    });
  }
  return items;
};

Note that when I can loop through returned objects, I add the absolute path to each object.

2- Now you filter your objects based on path ou subpath your are interested in.

3- Bulk update using their path