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Introduction

Working with Firestore document snapshots often requires extracting data and document IDs. The readSnapshot function automates this process, making it more efficient and error-proof, especially when dealing with non-existent documents.

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Key Features

  • Convenience: Automatically extracts data and ID from a Firestore document snapshot.
  • Safety: Returns undefined for non-existent documents, avoiding null reference errors.
  • Generic Typing: Supports generic typing for document data, ensuring type safety.

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Utilization

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Preparing for Document Reads

Import readSnapshot and use it to read data from a Firestore document snapshot:

import { firestore } from 'firebase-admin'
import { readSnapshot } from 'path-to-your-utilities'

// Assuming 'docSnapshot' is a Firestore document snapshot
const docSnapshot: firestore.DocumentSnapshot = firestore()
  .doc('path/to/doc')
  .get()

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Extracting Data from a Snapshot

Invoke readSnapshot with a document snapshot to get the document’s data and ID:

// Read data from the snapshot
const docData = readSnapshot(docSnapshot)

// docData contains the document's data and ID, or is undefined if the document doesn't exist

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Handling Non-Existent Documents

readSnapshot gracefully handles non-existent documents by returning undefined, allowing for easy checking and preventing errors due to null or undefined values.

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Best Practices

  • Use readSnapshot in Firestore read operations to standardize how you handle document data extraction.
  • Combine readSnapshot with other Firestore utilities to create a cohesive data handling workflow.
  • Always check for undefined returns when dealing with optional or non-existent documents.

Ensure that you handle the undefined case in your code to gracefully manage scenarios where the document does not exist.