我想获取异步函数的结果-根据结果,我想执行另一个函数或继续for循环。这是我的云端功能:
return query.get().then(geoSnapshot => {
// If GeoquerySnapshot returns 0 docs, createDoc()
let docs = geoSnapshot.docs;
if (docs.length === 0) return createDoc(data);
for(let [index, doc] of docs.entries()){
// If age preferences are valid, joinDoc
let currentDoc = docs[index].data();
if (validAge(currentDoc, data)){
let matchedBefore = await(matchedBefore(currentDoc, data))
if (!matchedBefore){
return joinDoc(docs[index], data);
} else if (index === (docs.length - 1)) {
return createDoc(data);
}
}
return
}
}).catch( error => {
console.log("error query: " + error);
return { error: error };
})
async function matchedBefore(currentDoc, data){
return db.collection('users').doc(data.uid).get().then( doc => {
if ( !doc.exists ) return false;
// If user1 in matchedUsers
let matchedUsers = doc.get('matchedUsers');
if (matchedUsers === undefined) return true
let matchedBefore = matchedUsers.includes(currentDoc.user1);
console.log('matchedBefore: ' + matchedBefore);
if (matchedBefore) {
return false
} else {
return true
}
})
}
我在let matchedBefore = await(matchedBefore(currentDoc, data))
上遇到以下错误:
Each then() should return a value or throw
如何确保函数matchedBefore()
在for循环继续之前完成?
答案 0 :(得分:1)
我认为您对async-await的实现过于困惑。正确的方法是:
return query.get().then(async geoSnapshot => {
// If GeoquerySnapshot returns 0 docs, createDoc()
let docs = geoSnapshot.docs;
if (docs.length === 0) return createDoc(data);
/* eslint-disable no-await-in-loop */
for(let [index, doc] of docs.entries()) {
// If age preferences are valid, joinDoc
let currentDoc = docs[index].data();
if (validAge(currentDoc, data)){
let matchedBefore = await(matchedBefore(currentDoc, data))
if (!matchedBefore){
return joinDoc(docs[index], data);
} else if (index === (docs.length - 1)) {
return createDoc(data);
}
}
return
}
/* eslint-enable no-await-in-loop */
}).catch( error => {
console.log("error query: " + error);
return { error: error };
})
async function matchedBefore(currentDoc, data){
let doc = await db.collection('users').doc(data.uid).get()
if ( !doc.exists ) return false;
// If user1 in matchedUsers
let matchedUsers = doc.get('matchedUsers');
if (matchedUsers === undefined) return true
let matchedBefore = matchedUsers.includes(currentDoc.user1);
console.log('matchedBefore: ' + matchedBefore);
return !matchedBefore
}