Immediate mode: instant, synchronous document updates

What is the feature? When doing something like drag and drop the updates to firestore take too long so the UI jumps. This is even worse with transactions.

What version would this apply to? v0.15

Do you have thoughts/examples on how the feature would be used (i.e. API)?

Yes. I already forked it and made it work: https://github.com/TARAAI/redux-firestore/pull/1

// Single document change w/ synchronous, optimistic data in Redux
firestore.mutate({ collection: 'collection/path', doc: 'document-id', someChange: 'value' });

// Batch multiple document changes w/ synchronous, optimistic data in Redux 
// (batches > 500 will be bundled and committed together)
firestore.mutate([
  { collection: 'collection/path', doc: 'document-id', someChange: 'value' },
  { collection: 'collection/path', doc: 'other-id', otherChange: 'otherValue' }
]);

// transactions w/ synchronous, optimistic data in Redux
firestore.mutate({
  read: { 
     myLockedDocument:  { 
        collection: 'path', 
        doc: 'document-id',
     }
  },
  write: [({ myLockedDocument }) => ({
      collection: 'path', 
      doc: 'document-id' , 
      someNumber: myLockedDocument.someNumber + 10
    })]
});

[puppybits]

@prescottprue Submitted a PR for this new reducer. The headline is that is’ 100x faster for all changes.

The reason is that even single save operations have to round-trip over the network before the snapshot listener fires. For us saving a Firestore transaction in production took a minimum of 1.2s to show the results to the user. That dropped to 6ms. That’s over 100x faster.

[puppybits]

@prescottprue I’ve updated our fork and integrated it into our app. Here’s an illustration of the issue and the difference between the 2 different reducers.

Before.

After.

We’re doing internal QA on our app but when it all passes we’d be happy to send a PR.

It does handle both success and failure cases when the firestore save reaches a resolution. Here’s a link to our internal PR review to see the details https://github.com/TARAAI/redux-firestore/pull/4.

Also we have an additional follow-on feature planned which would unify single document changes, batches, transactions and optimistic updates into a single API call so manually sending an optimistic update would no longer be needed.