Node.js 你能帮我吗?-firebase功能更新
我想使用Node.js 你能帮我吗?-firebase功能更新,node.js,firebase,google-cloud-firestore,google-cloud-functions,Node.js,Firebase,Google Cloud Firestore,Google Cloud Functions,我想使用onUpdate函数在“front”更新时触发,但不幸的是,我无法让它工作。你能帮我吗 exports.updateUser = functions.firestore .document('trashcan/{trashcanId}') .onUpdate((change, context) => { 'front'; // Get an object representing the document // e.g. {'name': 'Marie', 'age':
onUpdate
函数在“front”更新时触发,但不幸的是,我无法让它工作。你能帮我吗
exports.updateUser = functions.firestore
.document('trashcan/{trashcanId}')
.onUpdate((change, context) => {
'front';
// Get an object representing the document
// e.g. {'name': 'Marie', 'age': 66}
const newValue = change.after.data();
// ...or the previous value before this update
const previousValue = change.before.data();
// access a particular field as you would any JS property
const front = newValue.front;
// perform desired operations ...
您应该在更改前后比较
front
字段的值,如下所示:
exports.detectFrontChanges = functions.firestore
.document('trashcan/{trashcanId}')
.onUpdate((change, context) => {
const newValue = change.after.data();
const previousValue = change.before.data();
if (newValue.front !== previousValue.front) {
//front field value has changed
//Do something
//e.g. write to the log console
console.log("front field value has changed!");
//e.g. and write a Firestore document
return admin.firestore().collection('events').doc('event1').set({changeType: 'front field'});
} else {
//nothing to do
//return null to indicate to the Cloud Function platform that this Function can be finished
return null;
}
}
如果您也发布了错误消息,这将有所帮助。