Ignore firebase.firestore.timestamp

Question

My project used @Nativescript/firebase(https://github.com/EddyVerbruggen/nativescript-plugin-firebase) ignores methods of firebase.firestore.timestamp, and returns undefined by properties.

The below is minimum reproduction

app.js

import Vue from "nativescript-vue";
import Home from "./components/Home";

var firebase = require("@nativescript/firebase").firebase;

firebase
  .init({})
  .then(
    function () {
      console.log("firebase.init done");
    },
    function (error) {
      console.log("firebase.init error: " + error);
    }
  );

new Vue({
  render: (h) => h("frame", [h(Home)]),
}).$start();

Home.vue

import { firebase } from "@nativescript/firebase";

export default {
  computed: {
    async message() {
      const Ref = firebase.firestore
        .collection("comments")
        .doc("07bhQeWDf3u1j0B4vNwG");
      const doc = await Ref.get();
      const hoge = doc.data();
      console.log("hoge.commented_at", hoge.commented_at); // CONSOLE LOG: hoge.commented_at Sat Oct 23 2021 22:44:48 GMT+0900 (JST)
      console.log("hoge.commented_at.seconds", hoge.commented_at.seconds); // CONSOLE LOG: hoge.commented_at.seconds undefined
      const hogeToDate = hoge.toDate();
      console.log("hogeToDate", hogeToDate); // no console.log appear
      return hogeToDate; // simulator shows "object Promise"
    },
  },
};

I also tried const hogeTimestampNow = firebase.firestore.Timestamp.now(); then no console.log appear...

Environment

vue.js
Node.js v14.17.6
nativescript v8.1.2
nativescript-vue v2.9.0
@nativescript/firebase v11.1.3

score 1 · Answer 1 · answered Nov 05 '21 at 12:58

If you dive into the source of @nativescript/firebase, in particular looking at /src/firebase-common.ts, you can see that firebase is a custom implementation and not the object/namespace normally exported by the ordinary Firebase Web SDK.

It uses a custom implementation so that it can be transformed depending on the platform the code is running on as shown in /src/firebase.android.ts and /src/firebase.ios.ts.

Of particular importance, is that Firestore's Timestamp objects are internally converted to JavaScript Date objects when exposed to your code as each platform has its own version of a Timestamp object. Because the exposed JavaScript Date object doesn't have a seconds property, you get undefined when attempting to access hoge.commented_at.seconds.

The equivalent of Timestamp#seconds would be Math.floor(hoge.commented_at / 1000) (you could also be more explicit with Math.floor(hoge.commented_at.getTime() / 1000) if you don't like relying on JavaScript's type coercion).

function getSeconds(dt: Date) {
  return Math.floor(dt.getTime() / 1000)
}

While you can import the Timestamp object from the Modular Web SDK (v9+), when passed into the NativeScript plugin, it would be turned into an ordinary object (i.e. { seconds: number, nanoseconds: number } rather than a Timestamp).

import { Timestamp } from 'firebase/firestore/lite';

const commentedAtTS = Timestamp.fromDate(hoge.commented_at);

docRef.set({ commentedAt: commentedAtTS.toDate() }) // must turn back to Date object before writing!

Thank you a lot! I understand how to convert to seconds in my project. — naokonakanish, Nov 05 '21 at 14:40

score 0 · Answer 2 · answered Nov 05 '21 at 14:55

firebase.firestore.timestamp does not work via @nativescript/firebase as @samthecodingman said.(https://stackoverflow.com/a/69853638/15966408)

Just use ordinally javascript methods and edit.

I tried

get timestamp from firestore then convert to milliseconds
get date with new Date() then convert to milliseconds

and same miliseconds logged.

via firestore

const Ref = firebase.firestore.collection("comments").doc("07bhQeWDf3u1j0B4vNwG");
const doc = await Ref.get();
const hoge = doc.data();
console.log("hoge.commented_at in milliseconds: ", Math.floor(hoge.commented_at / 1000)); 
// CONSOLE LOG: hoge.commented_at in milliseconds:  1634996688

via javascript methods

const getNewDate = new Date("October 23, 2021, 22:44:48 GMT+0900"); 
// same as hoge.commented_at
console.log("getNewDate in milliseconds: ", getNewDate.getTime() / 1000); 
// CONSOLE LOG: getNewDate in milliseconds:  1634996688

Ignore firebase.firestore.timestamp

2 Answers2