The library has undergone a major rewrite. As such it's drastically different from 0.6.1. The API changed, hopefully for the best. Its scope also changed a bit, so some features that were in 0.6.1 have been dropped in 2.0.0. Of course the reverse is also true.

Most notable changes

Installing the library

In 0.6.1 the library was distributed as a bundle for client-side consumption, and could be installed via bower or npm. It was not possible though to require via browserify or webpack, require-ing it only worked in node.

In 2.0.0 the library is distributed as an npm module. It's not distributed as a bundle though, so you can't download it and include it as a script in your html. If publishing it as a bundle (through npm and/or bower) is needed, please open an issue and I'll add support for it.

The change was made to support require-ing the library in client-side code. The bundle is not distributed just because we haven't had the time to do so.
Obtaining the Asteroid class

In 0.6.1 the module exported a class, Asteroid.

In 2.0.0 the module exports a createClass function, which is used to create the Asteroid class.

The change was made to allow adding functionalities to the class via mixins (see docs).
```
// 0.6.1
const Asteroid = require("asteroid");
const asteroid = new Asteroid(/* ... */);

// 2.0.0
const createClass = require("asteroid").createClass;
const Asteroid = createClass();
const asteroid = new Asteroid(/* ... */);
```

Creating Asteroid instances

The signature of the Asteroid class constructor changed.

The change was made to allow to specify options which mixins might need.

// 0.6.1
const asteroid = new Asteroid(host, useSsl, interceptorFunction);

// 2.0.0
// The `optionsObject` now takes whatever options needed by the used mixins.
const asteroid = new Asteroid(optionsObject);

Calling methods

In 0.6.1 the call and apply methods returned an object with two properties: result and updated. result was a promise to the method invocation result. updated was a promise which resolved when the server sent an updated message for the invocation.

In 2.0.0 both methods return directly a promise to the invocation result. The library does not currently offer a way to listen for the updated event (it can be done by doing something like asteroidInstance.ddp.on("updated", handler)).

The change was made to simplify method calls (it seemed more idiomatic for a js library to have this API).
```
// 0.6.1
asteroid.call("myMethod", 1, 2, 3).result.then(ret => {
    console.log(ret);
});

// 2.0.0
asteroid.call("myMethod", 1, 2, 3).then(ret => {
    console.log(ret);
});
```
Subscribing to publications

In 0.6.1 the subscribe method returned an object containing:
- a stop method, which could be called to terminate the subscription
- a ready property, a promise which resolved when the server marked the subscription as ready
In 2.0.0 the subscribe method returns an object containing:
- an id property, which can be used to terminate the subscription by passing it to the unsubscribe method
- an on method (the object is an event emitter), which can be used to register a handler for the ready, error (and soon also the stopped) events
The change was made to allow a finer-grained management of subscriptions.
Managing collections

0.6.1 handled collections.

2.0.0 simply doesn't. Handling collections is delegated to third party mixins, such as asteroid-immutable-collections-mixin.

The change was made because in many projects we found ourselves not using Asteroid's collections, but rather re-implementing them in some other way (e.g. as immutable maps). To avoid wasting cpu time and memory storing them in Asteroid directly, we preferred to leave managing them to external mixins. Admittedly, there is currently no mixin that replicates the old behaviour. If you developed one or plan to do so, be sure to let us know and we'll list it in the mixins section in the README.
Using reactiveQuery-s

reactiveQuery-s were a feature of collections. As such, they have also been dropped in 2.0.0.