CODEWITHSUNDEEP
typescriptfirebasegoogle-cloud-functionsfirebase-cloud-messaging
Hudson Kim
Hudson Kim

Reputation: 486

How do I get a document field from a specific document in Firestore using Typescript?

I am currently trying to use Firebase Cloud Functions in my Flutter application. In my application, I want to retrieve a document field from a certain document when an event happens using typescript. I have done the same thing before in dart however I am unsure of what to do when using typescript. In the code below I attempt to get the field from the document using a method in dart however it fails in typescript with the following error:

Property 'snapshot' does not exist on type 'DocumentReference<DocumentData>'. Did you mean 'onSnapshot'?

I have simplified the code to one cloud function with the most important parts having comments before them. I am trying to get the nickname field from the personFrom documentReference.

const db = admin.firestore();
const fcm = admin.messaging();

export const sendToDevice = functions.firestore
    .document('messages/{groupChatId}/{chatId}/{message}')
    .onCreate(async (snapshot: { data: () => any; }) => {


        const message = snapshot.data();
        if (message != null) { 
            const querySnapshot = await db
                .collection('messages')
                .doc(message.idTo)
                .collection('tokens')
                .get();


// **** This is where I am referencing the document where I want to get its fields ****

var personFrom = db.collection('messages').doc(message.idFrom).snapshot();

        const tokens = querySnapshot.docs.map((snap: { id: any; }) => snap.id);

        const payload: admin.messaging.MessagingPayload = {
            notification: {
// **** Right here in the title parameter is where I am attempting to retrieve a specific field of data from the document I mentioned above ****
                title: "New Message from" + personFrom["nickname"]+ "!",
                body: message.content,
                icon: 'your-icon-url',
                click_action: 'FLUTTER_NOTIFICATION_CLICK'
            }
        };

        return fcm.sendToDevice(tokens, payload);

        } else {
            return undefined
        }
    });

Upvotes: 0

Views: 3346

Answers (1)

Doug Stevenson
Doug Stevenson

Reputation: 317712

In JavaScript, you use get() on a DocumentReference to fetch a document. It returns a promise that resolves with a DocumentSnapshot object:

const personFrom = await db.collection('messages').doc(message.idFrom).get();
const data = personFrom.data();

Now, data has a JavaScript object that describes the contents of the document.

Upvotes: 2

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