Node.js can be a platform crafted on Chrome's JavaScript runtime for conveniently making rapidly, scalable network purposes. Node.js employs an occasion-pushed, non-blocking I/O design that makes it light-weight and effective, great for knowledge-intensive serious-time apps that run throughout distributed equipment. NowJS can be a framework constructed in addition to Node.js that connects the consumer side and server aspect JavaScript effortlessly.

The Main of NowJS functionality lies from the now object. The now item is Specific because it exists to the server as well as the client.

What this means is variables you set from the now object are quickly synced amongst the client along with the server. Also server functions is often immediately termed within the client and customer functions might be called straight from the server.

You can have a Performing HTTP server up and operating in NodeJS with just some lines of code. Such as:


var http = demand('http');

http.createServer(functionality (req, res)

res.writeHead(200, 'Written content-Sort': 'textual content/basic');

res.close('Howdy Worldn');

).hear(8080);
This tiny snippet of code will build an HTTP server, pay attention on port 8080, and mail back again "Good day Planet" For each and every request. Which is it. Absolutely nothing extra necessary.

Utilizing NowJS, interaction in between the customer and server side is equally as easy.

Customer Facet:



On this code snippet, the shopper side sets a variable to 'someValue' and phone calls serverSideFunction(), that is declared only about the server.

Server Side:


Absolutely everyone.now.serverSideFunction = functionality()

console.log(this.now.clientSideVariable);


The server facet is then in a position to entry clientSideVariable, which is declared only within the shopper.

All the details for instance establishing connections and communicating improve of data involving the server and client are handed automagically through the framework.

In actual fact creating code working with this framework is so simple, the NowJS howdy environment example can be a Doing the job chat consumer and server prepared in less than a dozen lines of code. Go test it out.

As a straightforward physical exercise to have snug Using the NowJS API, we could modify the chat shopper example to assist various chat rooms. Let's Have a look at how uncomplicated it is.

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 the identical chat place given that the user.


// Deliver concept to Anyone within the consumers team

Anyone.now.distributeMessage = perform(concept)

var team = nowjs.getGroup(this.now.serverRoom);

team.now.receiveMessage(this.now.name+'@'+this.now.serverRoom, message);

;
We retailer the identify of your server room within the customer side (this.now.serverRoom). Once the customer phone calls the distributeMessage() function we deliver the concept to Absolutely everyone in a similar chat room by utilizing getGroup() and using the team.now item in lieu of theeveryone.now object. (everyone is just a group that contains all end users linked to the server).

two. Next we need to manage the customer switching chat rooms.


everyone.now.changeRoom = perform(newRoom)

var oldRoom = this.now.serverRoom;

//if previous place will not be null; then go away the old room

if(oldRoom)

var oldGroup = nowjs.getGroup(oldRoom);

oldGroup.removeUser(this.consumer.clientId);



// be a part of The brand new place

var newGroup = nowjs.getGroup(newRoom);

newGroup.addUser(this.person.clientId);

// update the shopper's serverRoom variable

this.now.serverRoom = newRoom;

;
The getGroup() method fetches the group object if it exists and generates a bunch if it won't exist already. We utilize the teams addUser() and removeUser() methods to move the client from your previous area to The brand new place.

Which is over it over the server facet.

Client Side (multiroom.html)

3. Initial we include a drop down With all the list of server rooms.




Home one

Room 2

Space 3


4. Up coming we get in touch with the server aspect changeRoom() operate once the consumer very first connects and Each time the fall down is transformed.


// on developing 'now' relationship, established the server home

now.Completely ready(functionality()

// By default decide on the first safe deposit boxes for sale chatroom

now.changeRoom($('#server-home').val());

);

// On improve of fall down, apparent textual content and alter server place

$('#server-place').transform(purpose()

$("#messages").html(");

now.changeRoom($('#server-place').val());

);
five. For further credit rating, we will allow the server to dynamically supply the list of rooms once the client connects.