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Cloud Firestore

Enabling Firestore

During plugin installation you'll be asked whether or not you use Firestore.

In case you're upgrading and you have the firebase.nativescript.json file in your project root, edit it and add: "firestore": true. Then run rm -rf platforms && rm -rf node_modules && npm i.

Functions

All of these are 100% compatible with the Firestore Web API to make it easy to share code between web and native, and you can refer to the Firestore web api docs (make sure to look at the 'WEB' tab of those code samples).

init / initializeApp

By default Firestore on iOS and Android persists data locally for offline usage (web doesn't by default, and the regular Firebase DB doesn't either on any platform). If you don't like that awesome feature, you can pass persist: false to the init function.

Note that initializeApp is simply an alias for init to make the plugin compatible with the web API.

const firebase = require("nativescript-plugin-firebase/app");

firebase.initializeApp({
  persist: false
});

collection

A 'collection' is at the root of any Firestore interaction. Data is stored as a 'document' inside a collection.

const citiesCollection = firebase.firestore().collection("cities");

collection.get()

To get all documents inside a collection:

const citiesCollection = firebase.firestore().collection("cities");

citiesCollection.get().then(querySnapshot => {
  querySnapshot.forEach(doc => {
    console.log(`${doc.id} => ${JSON.stringify(doc.data())}`);
  });
});

collection().onSnapshot()

To listen to changes in a certain collection, you can register a callback function that gets invoked every time data is changed.

To unsubscribe the listener, just invoke the function that was returned when attaching the listener.

NOTE: Due to a bug in the iOS Firestore SDK 'unsubscribe' does not currently work (plugin version 5.0.0), so the plugin is silently ignoring further updates after unsubscribing. This should not hurt your usage in any way though.

const citiesCollection = firebase.firestore().collection("cities");

const unsubscribe = citiesCollection.onSnapshot((snapshot: firestore.QuerySnapshot) => {
  snapshot.forEach(city => console.log(city.data()));
});

// then after a while, to detach the listener:
unsubscribe();

Using Observables? Check the example in the demo app.

collection.doc()

As mentioned, a document lives inside a collection and contains the actual data:

const citiesCollection = firebase.firestore().collection("cities");
const sanFranciscoDocument = citiesCollection.doc("SF");

collection.doc().get()

To get the data inside a document (and check whether or not the document actually exists):

const sanFranciscoDocument = firebase.firestore().collection("cities").doc("SF");

sanFranciscoDocument.get().then(doc => {
  if (doc.exists) {
    console.log(`Document data: ${JSON.stringify(doc.data())}`);
  } else {
    console.log("No such document!");
  }
});

collection.doc().onSnapshot()

To listen to changes in a certain document, you can register a callback function that gets invoked every time data is changed.

To unsubscribe the listener, just invoke the function that was returned when attaching the listener.

NOTE: Due to a bug in the iOS Firestore SDK 'unsubscribe' does not currently work (plugin version 5.0.0), so the plugin is silently ignoring further updates after unsubscribing. This should not hurt your usage in any way though.

const sanFranciscoDocument = firebase.firestore().collection("cities").doc("SF");

const unsubscribe = sanFranciscoDocument.onSnapshot(doc => {
  if (doc.exists) {
    console.log("Document data:", JSON.stringify(doc.data()));
  } else {
    console.log("No such document!");
  }
});

// then after a while, to detach the listener:
unsubscribe();

Using Observables? Check the example in the demo app.

collection.add()

If you want to add a document with an auto-generated ID, use add on a collection:

const citiesCollection = firebase.firestore().collection("cities");

citiesCollection.add({
  name: "San Francisco",
  state: "CA",
  country: "USA",
  capital: false,
  population: 860000,
  location: firebase.firestore().GeoPoint(4.34, 5.67)
}).then(documentRef => {
  console.log(`San Francisco added with auto-generated ID: ${documentRef.id}`);
});

collection.doc().set()

If you want to specify an ID yourself, use set on a document:

const citiesCollection = firebase.firestore().collection("cities");

citiesCollection.doc("SF").set({
   name: "San Francisco",
   state: "CA",
   country: "USA",
   capital: false,
   population: 860000
});

citiesCollection.doc("LA").set({
  name: "Los Angeles",
  state: "CA",
  country: "USA",
  capital: false,
  population: 3900000
});

collection.doc().update()

Update any number of properties of a document.

Note that you can use the special serverTimestamp() function to update a server timestamp (as opposed to a local timestamp, which would be different for every client):

Web API

const firebase = require("nativescript-plugin-firebase/app");

firebase.firestore().FieldValue().serverTimestamp()

Native API

import { firestore } from "nativescript-plugin-firebase";

firestore.FieldValue.serverTimestamp()

And this is what an update would look like, using the Web API:

const sanFranciscoDocument = firebase.firestore().collection("cities").doc("SF");

sanFranciscoDocument.update({
  population: 860001,
  updateTimestamp: firebase.firestore().FieldValue().serverTimestamp(),
  location: firebase.firestore().GeoPoint(4.34, 5.67)
}).then(() => {
  console.log("SF population updated");
});

collection.where()

Firestore supports advanced querying with the where function. Those where clauses can be chained to form logical 'AND' queries:

You can use the operators defined in firestore.WhereFilterOp, which are: '<' | '<=' | '==' | '>=' | '>' | 'array-contains'.

const citiesCollection = firebase.firestore().collection("cities");

// "Gimme all cities in California with a population below 550000"
const query = citiesCollection
    .where("state", "==", "CA")
    .where("population", "<", 550000);

query
    .get()
    .then(querySnapshot => {
      querySnapshot.forEach(doc => {
        console.log(`Relatively small Californian city: ${doc.id} => ${JSON.stringify(doc.data())}`);
      });
    });

Delete an entire document: collection.doc().delete()

Entirely remove a document from a collection:

const sanFranciscoDocument = firebase.firestore().collection("cities").doc("SF");

sanFranciscoDocument.delete().then(() => {
  console.log("SF was erased from the face of the earth!");
});

Delete specific fields in a document

To delete one or more fields in a document, do this (showing two flavors, use whatever you fancy):

import { firestore } from "nativescript-plugin-firebase");
const firebase = require("nativescript-plugin-firebase/app");

firebase.firestore().collection("dogs").doc("fave")
    .update({
      field1ToDelete: firestore.FieldValue.delete(),
      field2ToDelete: firebase.firestore().FieldValue().delete(),
    });

Adding to (arrayUnion) and removing from (arrayRemove) Arrays

If your document contains an array field, you can use arrayUnion() and arrayRemove() to add and remove elements.

arrayUnion() adds elements to an array but only elements not already present:

import { firestore } from "nativescript-plugin-firebase";
const firebase = require("nativescript-plugin-firebase/app");

firebase.firestore().collection("dogs").doc("fave")
    .update({
      // you can either use this syntax:
      colors1: firebase.firestore().FieldValue().arrayUnion("red", "blue"),
      //.. or this one:
      colors2: firestore.FieldValue.arrayUnion("red", "blue")
    });

arrayRemove() removes all instances of each given element:

firebase.firestore().collection("dogs").doc("fave")
    .update({
      colors: firebase.firestore().FieldValue().arrayRemove("red")
    });

Ordering and limiting results of collection.where()

Return data sorted (asc or desc), or limit to a certain number of results:

Make sure to checkt the comment on the .catch below.

const citiesCollection = firebase.firestore().collection("cities");

// "Gimme the two largest cities in California, the largest first please"
const query = citiesCollection
    .where("state", "==", "CA")
    .orderBy("population", "desc")
    .limit(2);

query
    .get()
    .then(querySnapshot => {
      querySnapshot.forEach(doc => {
        console.log(`Large Californian city: ${doc.id} => ${JSON.stringify(doc.data())}`);
      });
    }).catch(err => console.log(err)); // make sure you add this because Firestore may request you to create an index for this query!

Paginate data with query cursors

You can use startAt, startAfter, endAt, and endBefore as documented for 'WEB' here.

Here's an example, grabbing cities ordered by name, starting after 'LA':

firebase.firestore().collection('cities')
  .doc('LA')
  .get()
  .then(doc => {
    firebase.firestore().collection('cities')
      .orderBy('name', 'asc')
      .startAfter(doc)
      .get()
      .then(snap => snap.forEach(doc => console.log(doc.id, doc.data())));
  });

Batched Writes: batch()

To perform a (mixed) sequence of set, update, and/or delete operations in an atomic fashion (everything is rolled back if 1 operation fails), use the batch feature.

// one batch can set/update/delete multiple documents
const sanFranciscoDocumentReference: firestore.DocumentReference = firebase.firestore().collection("cities").doc("SF");
const sacramentoDocumentReference: firestore.DocumentReference = firebase.firestore().collection("cities").doc("SAC");

firebase.firestore().batch()
    .set(sanFranciscoDocumentReference, {capital: false}, {merge: true})
    .update(sanFranciscoDocumentReference, {population: 5})
    .update(sacramentoDocumentReference, {population: 6})
    .commit()
    .then(() => console.log("Batch successfully committed"))
    .catch(error => console.log("Batch error: " + error));

Need proof these batches are atomic? Try deleting and then updating a document 😉

firebase.firestore().batch()
    .delete(sanFranciscoDocumentReference)
    .update(sanFranciscoDocumentReference, {population: 7})
    .commit()
    .then(() => console.log("Batch successfully committed"))
    .catch(error => console.log(`Batch error: ${error}`));

Transactional Updates: runTransaction() (iOS only)

There's a technical hurdle which prevents this from working on Android.

In contrast to batch you can runTransaction to also be able to use get, but only use get before calling set, update, or delete (or the transaction will fail).

const sanFranciscoDocumentReference: firestore.DocumentReference = firebase.firestore().collection("cities").doc("SF");

firebase.firestore().runTransaction(transaction => {
  const doc = transaction.get(sanFranciscoDocumentReference);
  if (!doc.exists) {
    console.log("City SF doesn't exist");
  } else {
    const newPopulation = doc.data().population + 1;
    console.log(`Updating city 'SF' to a new population of: ${newPopulation}, and flipping the 'capital' state to ${sfDoc.data().capital}.`);

    transaction
        .set(sanFranciscoDocumentReference, {capital: !doc.data().capital}, {merge: true})
        .update(sanFranciscoDocumentReference, {population: newPopulation})
  }
  return null;
})
   .then(() => console.log("Transaction successfully committed"))
   .catch(error => console.log(`Transaction error: ${error}`));