snap.data 不是 onUpdate 中的函数

Question

我有两个触发onCreate和onUpdate的函数，但是，onUpdate中的{uid}返回undefined，而onCreate返回{uid}。

我怎样才能让{uid}为onUpdate工作？

onUpdate.f.js-{uid}undefined

exports = module.exports = functions.firestore
.document('users/{uid}/alerts/{name}') //UID is the User ID value stored in alerts
.onUpdate(snap => {
const user = snap.data();
console.log(user);
const msg = {
to: user.email,
from: '[e-mail]',
templateId: user.template,
dynamic_template_data: {
firstName: user.firstName,
email: user.email,
id: user.uid
}
};
return sgMail.send(msg).catch(err => console.log(`${user.email} - ${err}`));
});

onCreate.f.js-{uid}是正确的

exports = module.exports = functions.firestore
.document('users/{uid}/alerts/{name}')
.onCreate(snap => {
const user = snap.data();
console.log(user);
const msg = {
to: user.email,
from: '[e-mail]',
templateId: user.template,
dynamic_template_data: {
firstName: user.firstName,
email: user.email,
id: user.uid
}
};
return sgMail.send(msg).catch(err => console.log(`${user.email} - ${err}`));
});

来自前端的警报doc中的字段

doCreateAlert = (id, email, firstName, lastName, alertType, transactionEmailId) => {
const db = this.firestore;
return db.doc(`users/${id}/alerts/${alertType}`).set({
uid: id,
name: alertType,
email: email,
firstName: firstName,
lastName: lastName,
template: transactionEmailId,
dateCreated: new Date(),
dateModified: new Date()
});
};

onUpdate 是通过使用onClick={this.updateAlert}作为更新数据库来触发

的

updateAlert = () => {
const { firebase, userID } = this.props;
const companyTypeSetup = db.doc(`users/${userID}/alerts/emailVerified`);
companyTypeSetup.update({
dateModified: new Date()
});
};

在前端我收到错误

Uncaught (in promise) Error: No document to update: projects/app/databases/(default)/documents/users/undefined/alerts/emailVerified

并且该函数永远不会运行。如果我在 Firestore 中手动更新doc，则在 Firebase 函数日志中出现错误，如下所示

TypeError: snap.data is not a function
at module.exports.functions.firestore.document.onUpdate.snap (/user_code/lib/auth/onUpdate.f.js:17:23)
at cloudFunctionNewSignature (/user_code/node_modules/firebase-functions/lib/cloud-functions.js:105:23)
at cloudFunction (/user_code/node_modules/firebase-functions/lib/cloud-functions.js:135:20)
at /var/tmp/worker/worker.js:754:24
at process._tickDomainCallback (internal/process/next_tick.js:135:7)

Answer 1

如指南所示，onUpdate有两个参数：change和context。之所以使用change是因为您可能希望在更新之前或更新之后访问该值。假设您想要更新后的值，它将如下所示：

exports = module.exports = functions.firestore
.document('users/{uid}/alerts/{name}') //UID is the User ID value stored in alerts
.onUpdate((change, context) => {
const user = change.after.data();
console.log(user);
const msg = {
to: user.email,
from: '[e-mail]',
templateId: user.template,
dynamic_template_data: {
firstName: user.firstName,
email: user.email,
id: user.uid
}
};
return sgMail.send(msg).catch(err => console.log(`${user.email} - ${err}`));
});

Answer 2

通过阅读处理事件数据中的文档，可以轻松解决问题。但是，如果您像我一样浏览文档，那么解决方案是

.onUpdate(change => {
const user = change.after.data();