The core of NowJS operation lies while in the now object. The now item is Unique mainly because it exists about the server and also the customer.
This implies variables you established inside the now item are routinely synced involving the consumer as well as server. Also server features can be right known as to the consumer and shopper functions is usually referred to as straight from the server.
You may have a Doing the job HTTP server up and working in NodeJS with just a few traces of code. For instance:
var http = have to have('http');
http.createServer(perform (req, res)
res.writeHead(two hundred, 'Content material-Form': 'text/simple');
res.finish('Hello there Worldn');
).listen(8080);
This very little snippet of code will produce an HTTP server, hear on port 8080, and send back again "Hello Entire world" for every request. Which is it. Nothing at all extra necessary.
Applying NowJS, communication involving the client and server side is just as uncomplicated.
Client Aspect:
In this code snippet, the customer facet sets a variable to 'someValue' and calls serverSideFunction(), and that is declared only around the server.
Server Aspect:
everyone.now.serverSideFunction = operate()
console.log(this.now.clientSideVariable);
The server side is then in the position to access clientSideVariable, that's declared only over the consumer.
All the main points such as establishing connections and communicating transform of data among the server and shopper are handed automagically from the framework.
The truth is crafting code utilizing this framework is so uncomplicated, the NowJS hello planet case in point is a Functioning chat shopper and server written in beneath a dozen strains of code. Go check it out.
As a simple exercising for getting comfy Together with the NowJS API, we can easily modify the chat client illustration to guidance multiple chat rooms. Let's Look into how quick it's.
Server Aspect (multiroom_server.js)
one. The very first thing we need to do is modify the distributeMessage() operate to only send out messages to users in exactly the same chat area given that the user.
// Deliver concept to All people in the end users team
All people.now.distributeMessage = functionality(message)
var group = nowjs.getGroup(this.now.serverRoom);
team.now.receiveMessage(this.now.identify+'@'+this.now.serverRoom, information);
;
We shop the title with the server home around the consumer aspect (this.now.serverRoom). In the event the client calls the distributeMessage() perform we ship the information to Anyone in exactly the same chat home by using getGroup() and using the group.now item in place of theeveryone.now item. (everyone seems to be just a group that contains all consumers safety deposit boxes for sale linked to the server).
two. Next we need to manage the customer transforming chat rooms.
Anyone.now.changeRoom = function(newRoom)
var oldRoom = this.now.serverRoom;
//if old space is just not null; then depart the outdated home
if(oldRoom)
var oldGroup = nowjs.getGroup(oldRoom);
oldGroup.removeUser(this.user.clientId);
// join the new space
var newGroup = nowjs.getGroup(newRoom);
newGroup.addUser(this.consumer.clientId);
// update the customer's serverRoom variable
this.now.serverRoom = newRoom;
;
The getGroup() strategy fetches the team item if it exists and makes a gaggle if it doesn't already exist. We use the groups addUser() and removeUser() ways to transfer the consumer through the outdated place to The brand new home.
Which is over it on the server side.
Client Side (multiroom.html)
3. Initial we include a drop down With all the list of server rooms.
four. Following we simply call the server aspect changeRoom() purpose if the consumer 1st connects and Each time the fall down is adjusted.
// on developing 'now' relationship, established the server area
now.All set(purpose()
// By default decide the 1st chatroom
now.changeRoom($('#server-place').val());
);
// On transform of fall down, obvious textual content and change server area
$('#server-space').modify(perform()
$("#messages").html(");
now.changeRoom($('#server-space').val());
);
5. For additional credit score, we are able to allow the server to dynamically offer the list of rooms when the shopper connects.