Gathering.js - How to use
=================

Keep list (and count) of online users in a Firebase web app - by isolated rooms or globally.

Initialization
--------------
```javascript
firebase.initializeApp({...});

// default/global gathering
var onlineUsers = new Gathering(firebase.database());

// Create an isolated space
var chatroom = new Gathering(firebase.database(), 'Special Name');

```

Joining, Leaving and Ending (removing) a gathering
---------------

```javascript
var gathering = new Gathering(firebase.database(), 'Gathering Name');

// Join Anonymously
gathering.join();

// Or Join with a unique id
// This will ensure unique presense of a user, even if opened on multiple browser tab or device
gathering.join(firebase.auth().currentUser.uid);

// Also can set a display name (along with or without unique id)
gathering.join(null, 'Superman');
gathering.join(firebase.auth().currentUser.uid, 'Superman');


// When I am finished with the gathering, I may leave
// When browser is closed/refreshed, current ser will automatically leave 
gathering.leave();

// When all user's have left, we can remove the room
gathering.end();
```

Let's do something with the user count and user name list
-----------------
```javascript
var gathering = new Gathering(firebase.database(), 'Gathering Name');

// Attach another callback function with user list (array)
// That function will be called (with the array of users) every time user list changed.
gathering.onUpdated(function(count, users) {
    console.log(gathering.roomName + ' have '+ count +' members.');
    console.log('Here is the updated users list -');
    for(var i in users) {
        console.log(users[i] + '(id: '+ i + ')');
    }
});
```