CODEWITHSUNDEEP
javascriptnode.jsgoogle-cloud-firestoregoogle-cloud-functionsfirebase-admin
ramluro
ramluro

Reputation: 87

Google Cloud Function to delete sub-collections on "missing documents

I have a Firestore collection called Posts, and each document in Posts could have a sub-collection called Post-Likes and/or Post-Comments. When I delete the Posts document, it does not delete the sub-collection so I am left with a reference to a missing document in Firestore which looks like this:

enter image description here

I am using the following code in my Google Cloud Function to find references in the Post collection with missing data, then for each document with a missing reference, I want to delete the sub-collections Post-Likes and Post-Comments. For now, I am just try to list the sub-collection document so I can delete them, but I am getting an error.

function deleteOrphanPostSubCollections() {

    let collectionRef = db.collection('Posts');

    return collectionRef.listDocuments().then(documentRefs => {
       return db.getAll(...documentRefs);
    }).then(documentSnapshots => {
       for (let documentSnapshot of documentSnapshots) {
          if (documentSnapshot.exists) {
            console.log(`Found document with data: ${documentSnapshot.id}`);
          } else {
            console.log(`Found missing document: ${documentSnapshot.id}`);
            return documentSnapshot.getCollections().then(collections => {
              return collections.forEach(collection => {
                console.log('Found subcollection with id:', collection.id);
              });
            });
          }
       }
       return
    });
}

However, I am getting the following error. Please help me resolve this issue.

enter image description here

Upvotes: 0

Views: 147

Answers (1)

Renaud Tarnec
Renaud Tarnec

Reputation: 83163

This is because there is not getCollections() method for a DocumentSnapshot.

If you want to list all the collections of the Document corresponding to the DocumentSnapshot, you need to use the listCollections() method, as follows:

documentSnapshot.ref.listCollections()
  .then(collections => {
    for (let collection of collections) {
      console.log(`Found subcollection with id: ${collection.id}`);
    }
  });

In addition, note that if you call an asynchronous method in a loop, it is recommended to use Promise.all() in order to return a single Promise that resolves when all the "input" Promises are resolved.

Upvotes: 2

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