What is the solution to the problem "How can you resolve the issue where 'Cannot set property 'ref' of undefined' occurs"?

Question

What is the solution to the problem "How can you resolve the issue where 'Cannot set property 'ref' of undefined' occurs"?

My goal is quite simple - I just want to retrieve data from Cloud Firestore.

Below is the code snippet I am using:

import React from 'react';
import firebase from "react-native-firebase";

export default class newsFeed extends React.Component {
 constructor() {
  this.ref = firebase.firestore().collection('keys')
}

 async load(id) {
  const doc = await this.ref.doc(id).get()
  if (doc.exists) {
    return doc.data()
  }
 }
}

However, I encounter an error: 'Cannot set property 'ref' of undefined'.

How can I troubleshoot this issue and what could be causing it?

For more information, I referred to this tutorial: https://medium.com/react-native-training/firebase-sdk-with-firestore-for-react-native-apps-in-2018-aa89a67d6934

javascript firebase react-native google-cloud-firestore

Answer 1

Answer №1

Arrow functions are typically quite useful.

 initiate = async (id) => { //...

Answer 2

Arrow functions are typically quite useful.

 initiate = async (id) => { //...

Answer 3

Answer №2

When exporting the class, it is important to ensure that you create an instance of it. Here's a better way to achieve this:

import React from 'react';
import firebase from "react-native-firebase";

class NewsFeed extends React.Component {
 constructor() {
  this.ref = firebase.firestore().collection('keys')
}

 async load(id) {
  const doc = await this.ref.doc(id).get()
  if (doc.exists) {
    return doc.data()
  }
 }
}

export default newsFeedInstance = new NewsFeed();

I hope this solution helps you out! :)

Answer 4

When exporting the class, it is important to ensure that you create an instance of it. Here's a better way to achieve this:

import React from 'react';
import firebase from "react-native-firebase";

class NewsFeed extends React.Component {
 constructor() {
  this.ref = firebase.firestore().collection('keys')
}

 async load(id) {
  const doc = await this.ref.doc(id).get()
  if (doc.exists) {
    return doc.data()
  }
 }
}

export default newsFeedInstance = new NewsFeed();

I hope this solution helps you out! :)

What is the solution to the problem "How can you resolve the issue where 'Cannot set property 'ref' of undefined' occurs"?

Answer №1

Answer №2

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