javascript 初始加载时做一些事情

Posted 2021-05-03

function handleActivitySubscription(snapshot, counter) {
  const initialLoad = counter === 1;
  snapshot.docChanges().forEach(function(change) {   
      if (initialLoad) {
        doSomething(change.doc.data());          
      } else {
        doSomethingElse(change.doc.data());          
      }      
    });
}

const handleActivitySubscriptionWithCounter = 
  createFnCounter(handleActivitySubscription, 0);

db.collection("activities").where("userID", "==", currentUserID)
  .onSnapshot(handleActivitySubscriptionWithCounter);