在firebase中添加集合文档长度的计数器

const functions = require('firebase-functions');
const admin = require('firebase-admin');

admin.initializeApp();

exports.updateCollectionCounter = functions.firestore
  .document('your_collection/{docId}')
  .onWrite((change, context) => {
    const collectionRef = admin.firestore().collection('your_collection');
    return collectionRef.get().then((snapshot) => {
      const count = snapshot.size;
      return admin.firestore().collection('counters').doc('collection_counter').set({ count });
    });
  });

firebase deploy --only functions

fetch('https://us-central1-your-project-id.cloudfunctions.net/updateCollectionCounter', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({}),
})
  .then((response) => response.json())
  .then((data) => {
    console.log('Collection counter updated successfully');
  })
  .catch((error) => {
    console.error('Error updating collection counter:', error);
  });