react-firestore-mobx-bindings

react-firestore-mobx-bindings

A lightweight library to bind firestore data into react components statefully via mobx.

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Uses MobX 4.x's onBecomeObserved/onBecomeUnobserved and mobx-react's inject/observer methods to provide a simple, scalable, and efficient mechanism for binding firestore data into react components. Components will automatically attach and detach realtime data listeners as they are mounted and unmounted from the react dom.

Why?

Because the less you have to manage your data, while still having full control over it, the better.

Firestore is a great service to allow all of your app data to exist non-locally while still appearing performant and seamless. The motivation of this library is to reduce the barrier to binding that app data into your react components, while still providing the power and control of using mobx in the data layer.

Setup

Install with

yarn add react-firestore-mobx-bindings

Then, provide the firestore factory to the React Context using MobxProvider from mobx-react:

import { Provider as MobxProvider } from 'mobx-react';
import { FirestoreObservableFactory } from 'react-firestore-mobx-bindings';

const factory = new FirestoreObservableFactory('my factory');

export const Root: React.StatelessComponent<> = () => {
  return (
    <MobxProvider AutoObservableFactory={factoryy}>
        ...
    </MobxProvider>
  );
};

NOTE: You must provide the factory to the MobxProvider as AutoObservableFactory in order for it to be located by the HOX and query component.

Usage

react-firestore-mobx-bindings provides a HOC method, or a query component, depending on your preference.

Using injectFirestore as a HOC:

const injectedByHoc = injectFirestore(
  firestore => ({
    users: firestore.collection('users'),
  }),
  ({ users }) => {
    if (users.isLoading) {
      return <Spinner/>
    } else if (users.data) {
      return <li> {users.data.map(user => <li>user.name</li>} </li>
    } else {
      return <p>No data</p>
    }
  }
);

Using FirestoreQueryComponent query component:

const queryComponent = () => {
  const selector = (firestore) => ({
    users: firestore.collection('users')
  });

  return <FirestoreQueryComponent selector={selector}>
    {({users}) => {
      if (users.isLoading) {
        return <Spinner/>
      } else if (users.data) {
        return <li> {users.data.map(user => <li>user.name</li>} </li>
      } else {
        return <p>No data</p>
      }
    }
  </FirestoreQueryComponent>
}

Queries and Documents

Both the HOC and Query component accept firestore queries and document references in their selectors

const queryComponent = (userId) => {
  const selector = (firestore) => ({
    user: firestore.collection('users').doc(userId),
    photos: firestore.collection('photos').where('userId', '==', userId)
  });

  return <FirestoreQueryComponent selector={selector}>
    {({user, photos}) => {
      ...
    }
  </FirestoreQueryComponent>
}

Key Uniqueness Constraint

The library uses the keys of the provided selector to re-use firestore references, hence you need to pay some attention to the names of your keys.

Hence, the following would provide a conflict, as both components use the same user key in their selector:

const queryComponent = (userId) => {
  const selector = (firestore) => ({
    user: firestore.collection('users').doc(userId)
  });

  return <FirestoreQueryComponent selector={selector}>
    {({user}) => {
      ...
    }
  </FirestoreQueryComponent>
}

...

const otherQueryComponent = (photoId, userId) => {
  const selector = (firestore) => ({
    user: firestore.collection('photos').doc(photoId).collection('taggedUsers').doc(userId)
  });

  return <FirestoreQueryComponent selector={selector}>
    {({user}) => {
      ...
    }
  </FirestoreQueryComponent>
}