Firebase:创建后获取文档快照 [英] Firebase: Get document snapshot after creating

问题描述

我知道我可以创建一个新查询以通过回调中的id读取文档.但是在创建文档或至少创建了TIMESTAMP之后，我可以在回调中获取整个快照吗?

I know that I can create a new query to read the doc by id in callback. But can I get the whole snapshot in the callback after creating document or at least TIMESTAMP?

firebase.firestore().collection("comments").add({
  body: data
})
.then(comment => {
  console.log(comment);
})
.catch(error => {
  console.log(error);
});

推荐答案

调用 CollectionRef.add(...)返回对新创建文档的引用.为了能够访问该新文档的数据，您仍然需要加载它.所以:

Calling CollectionRef.add(...) return a reference to the newly created document. To be able to access the data of that new document you'll need to still load it. So:

firebase.firestore().collection("48486654").add({
  timestamp: firebase.firestore.FieldValue.serverTimestamp()
})
.then(function(docRef) {
  docRef.get().then(function(doc) {
    console.log(doc.data().timestamp.toString());
  });
})
.catch(function(error) {
  console.error(error);
});

有关工作示例，请参见: https://jsbin.com/xorucej/edit?js控制台

For a working example, see: https://jsbin.com/xorucej/edit?js,console

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