aggregateSpec use unclear

[marekves]

Hello could you please provide a clear explanation how aggregateSpec in useAggregateFromServer is to be defined? Its currently very unclear what the input is. Thx for the and help and the lib!

[andipaetzold]

Hey 👋

the best documentation is probably from firebase: https://firebase.google.com/docs/firestore/query-data/aggregation-queries#calculate_multiple_aggregations_in_a_query

The argument list of firestore's getAggregateFromServer and react-firehooks' useAggregateFromServer are identical.

// Example from firestore docs
const coll = collection(firestore, 'cities');
const snapshot = await getAggregateFromServer(coll, {
  countOfDocs: count(),
  totalPopulation: sum('population'),
  averagePopulation: average('population')
});

console.log('countOfDocs: ', snapshot.data().countOfDocs);
console.log('totalPopulation: ', snapshot.data().totalPopulation);
console.log('averagePopulation: ', snapshot.data().averagePopulation);

// Usage with react-firehooks
const coll = collection(firestore, 'cities');
const [data] = useAggregateFromServer(coll, {
  countOfDocs: count(),
  totalPopulation: sum('population'),
  averagePopulation: average('population')
});

console.log('countOfDocs: ', data?.countOfDocs);
console.log('totalPopulation: ', data?.totalPopulation);
console.log('averagePopulation: ', data?.averagePopulation);

[marekves]

Thank you for the clarification.