Getting In Sync

The Sync API

Last week saw the first Alpha release of the AeroGear Sync Server.

Our Sync Server is an implementation of the Differential Synchronization Algorithm by Neil Fraser

The Main new feature of this JS release is the Sync Server Client SDK.

The SDK has 2 flavors of engines to interact with the Sync Server:

JSON Patch and Diff Match Patch

In our JS cookbook, We have created an Example that uses the JSON Patch Engine

Lets see an example:

syncClient = AeroGear.DiffSyncClient({
    serverUrl: 'ws://localhost:7777/sync',
    onopen: function () {},
    onsync: function () {}

Here we call the DiffSyncClient constructor with some options. You will notice that we are using Websockets as our transfer protocol.

By default, the JSON Patch engine will be used.

Then to add a “Document” which is really just an object, we can call the addDocument method


If we need to get that document back out of the engine, we can use the fetch method:


And when we make changes to our document, we call the sync method:


Each of the above methods will result in the onsync callback to be called

We define a specific format for the document:

var document = {
    id: ...,
    clientId: ...,
	content: { ... }

This New API is currently marked as experimental, so we encourage everyone to try it out and let us know what works and what doesn’t.

Polyfill Removal

Prior to this release, we were embedding the ES6 Promise Polyfill.

Now that almost all Major browers are supporting Promises natively we’ve decided to not include it.

If you still need to support a browser without native support, you will need to include the polyfill

Deprecations and Removals


This release we removed the Authz module completely from the library. This module was marked as experimental and it didn’t really add much value anyway.


The AeroGear.ajax module, which was just an internal thing, has also been removed. There was only one place it was being used, the Unified Push Client SDK, so it didn’t make sense anymore to have this as a standalone thing.


We also started the Deprecation process for the Notifier Module.

The abstraction that notifier provides no longer makes sense. The code will eventually be removed in a Major release.

Get the Code

The usual spots still apply.

Source Code:


bower install aerogear

There are some “pre-built” components that can be installed with bower from the AeroGear Components repo

Release Notes - AeroGear JavaScript - Version 2.1.0


  • [AGJS-289] - Diff Sync Example doesn't build due to Ember CLI error


  • [AGJS-265] - Remove base64 polyfill
  • [AGJS-266] - Add all tests to the Qunit Test Suite index Page
  • [AGJS-267] - Update sock.js cdn for examples that use it


  • [AGJS-260] - Implement JavaScript Client Sync Engine

Feature Request

  • [AGJS-70] - Remove jQuery requirement
  • [AGJS-124] - Create a Diff Sync Client
  • [AGJS-268] - Move Sync Server js-client example to cookbook
  • [AGJS-279] - Merge AeroGear.ajax into UnifiesPush Client
  • [AGJS-281] - Deprecate Notifier
  • [AGJS-287] - Update Sync Lib to not use "Array Pattern"


  • [AGJS-257] - Remove ES6 polyfil
  • [AGJS-269] - Deprecate Authorization module
  • [AGJS-270] - Deprecate Google Drive cookbook example
  • [AGJS-275] - JavaScript Client Engine should support JSON Patch
  • [AGJS-280] - Remove Authz and AeroGear.ajax related stuff from builder


  • [AGJS-254] - Make ES6 promise polyfill optional
  • [AGJS-256] - README Library Deps need updating
  • [AGJS-258] - Remove promise polyfill from custom builder
  • [AGJS-259] - Update Dist repo with promise removal