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export const documentWriteListener = functions.firestore
.document('collection/{documentUid}')
.onWrite((change, context) => {
if (!change.before.exists) {
// New document Created : add one to count
db.doc(docRef).update({ numberOfDocs: FieldValue.increment(1) });
} else if (change.before.exists && change.after.exists) {
// Updating existing document : Do nothing
} else if (!change.after.exists) {
// Deleting document : subtract one from count
db.doc(docRef).update({ numberOfDocs: FieldValue.increment(-1) });
}
return;
});
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const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp();
exports.aggregateComments = functions.firestore
.document('posts/{postId}/comments/{commentId}')
.onWrite(event => {
const commentId = event.params.commentId;
const postId = event.params.postId;
// ref to the parent document
const docRef = admin.firestore().collection('posts').doc(postId)
// get all comments and aggregate
return docRef.collection('comments').orderBy('createdAt', 'desc')
.get()
.then(querySnapshot => {
// get the total comment count
const commentCount = querySnapshot.size
const recentComments = []
// add data from the 5 most recent comments to the array
querySnapshot.forEach(doc => {
recentComments.push( doc.data() )
});
recentComments.splice(5)
// record last comment timestamp
const lastActivity = recentComments[0].createdAt
// data to update on the document
const data = { commentCount, recentComments, lastActivity }
// run update
return docRef.update(data)
})
.catch(err => console.log(err) )
});