我正在尝试在添加新邮件时通过Firebase Cloud 功能向群组中的每个成员发送推送通知 . 我不习惯使用Promises,需要一些帮助 .
exports.sendPushFromMessage = functions.database.ref('chats/{groupId}/messages/{msgId}').onCreate((snap, context) => {
const groupId = context.params.groupId;
const users = [];
const msgTitle = 'New Message';
const msgBody = snap.val().messageText;
const creator = snap.val().from;
const root = snap.ref.root;
let messages = [];
return root.child(`groups/${groupId}/selected`).once('value', snapshot => {
snapshot.forEach(user => {
root.child(`users/${user.val().uid}`).once('value', spanshot => {
const expoToken = snapshot.val().token;
const userId = snapshot.val().uid;
if (expoToken && (creator !== userId)) {
messages.push({
"to": expoToken,
"title": msgTitle,
"body": msgBody
});
}
})
})
return messages;
}).then(messages => {
return fetch('https://exp.host/--/api/v2/push/send', {
method: "POST",
headers: {
"Accept": "application/json",
"Content-Type": "application/json"
},
body: JSON.stringify(messages)
})
}).catch((e) => console.log(e));
})
在Firebase函数的日志中,我可以看到以下错误:
函数返回未定义,预期的Promise或value
我知道问题可能就是我如何处理Promises . 这个问题困扰了我很长一段时间,如果有人能帮助我会很棒 .
这是我尝试的另一种方法:
exports.sendPushFromMessage = functions.database.ref('chats/{groupId}/messages/{msgId}').onCreate((snap, context) => {
const groupId = context.params.groupId;
const users = [];
const msgTitle = 'New Message';
const msgBody = snap.val().messageText;
const creator = snap.val().from;
const root = snap.ref.root;
root.child(`groups/${groupId}/selected`).once('value', snapshot => {
let users = [];
snapshot.forEach(user => {
const uid = user.val().uid;
users.push(uid);
console.log('fotze' + user.val().uid);
})
return Promise.all(users);
})
.then(users => {
let messages = [];
console.log(users);
users.forEach(user => {
console.log('fucking bitch: ' + user.toString());
console.log('bitch!' + user);
root.child(`users/${user}/`).once('value', snapshot => {
const expoToken = snapshot.val().token;
const userId = snapshot.val().uid;
console.log('cunt' + snapshot.val().token);
if (expoToken && (creator !== userId)) {
messages.push({
"to": expoToken,
"title": msgTitle,
"body": msgBody
})
} // if
}); // once
}); //forEach
return Promise.all(messages);
})
.then(messages => {
return fetch('https://exp.host/--/api/v2/push/send', {
method: "POST",
headers: {
"Accept": "application/json",
"Content-Type": "application/json"
},
body: JSON.stringify(messages)
})
}).catch((e) => console.log(e));
})
1 回答
请以这种方式测试: