The Main of NowJS performance lies in the now item. The now object is special mainly because it exists about the server as well as the shopper.
What this means is variables you set from the now object are quickly synced among the client and also the server. Also server capabilities could be directly named around the shopper and consumer capabilities could be termed directly from the server.
You might have a Functioning HTTP server up and running in NodeJS with just a couple lines of code. By way of example:
var http = require('http');
http.createServer(purpose (req, res)
res.writeHead(200, 'Information-Kind': 'textual content/basic');
res.finish('Hello there Worldn');
).listen(8080);
This very little snippet of code will generate an HTTP server, listen on port 8080, and ship back "Hi World" For each ask for. That's it. Very little a lot more desired.
Utilizing NowJS, interaction in between the customer and server facet is just as uncomplicated.
Client Aspect:
Within this code snippet, the consumer facet sets a variable to 'someValue' and calls serverSideFunction(), that's declared only over the server.
Server Side:
All people.now.serverSideFunction = function()
console.log(this.now.clientSideVariable);
The server facet is then capable of entry clientSideVariable, which is declared only about the shopper.
All the details for example establishing connections and communicating transform of data among the server and customer are handed automagically by the framework.
In reality crafting code utilizing this framework is so basic, the NowJS good day globe illustration is a Doing the job chat consumer and server written in beneath a dozen strains of code. Go check it out.
As an easy work out to get comfy Together with the NowJS API, we can easily modify the chat client instance to guidance various chat rooms. Let's Have a look at how uncomplicated it is actually.
Server Side (multiroom_server.js)
one. The very first thing we must do is modify the distributeMessage() function to only ship messages to people in the same chat space since the person.
// Mail message to Everybody inside the people team
everyone.now.distributeMessage = perform(concept)
var team = nowjs.getGroup(this.now.serverRoom);
team.now.receiveMessage(this.now.identify+'@'+this.now.serverRoom, message);
;
We retailer the title with the server space about the client aspect (this.now.serverRoom). If the shopper phone calls the distributeMessage() function we deliver the concept to All people in a similar chat room by utilizing getGroup() and using the team.now item in lieu of theeveryone.now item. (everyone is just a group that contains all consumers linked to the server).
two. Future we must handle the consumer modifying chat rooms.
Absolutely everyone.now.changeRoom = purpose(newRoom)
var oldRoom = this.now.serverRoom;
//if aged home is not really null; then leave the old room
if(oldRoom)
var oldGroup = nowjs.getGroup(oldRoom);
oldGroup.removeUser(this.consumer.clientId);
// be a part of The brand new area
var newGroup = nowjs.getGroup(newRoom);
newGroup.addUser(this.person.clientId);
// update the shopper's serverRoom variable
this.now.serverRoom = newRoom;
;
The getGroup() process fetches the group object if it exists and creates a group if it does not already exist. We make use of the teams addUser() and removeUser() techniques to go the customer within the aged home to the new room.
That's about it around the server aspect.
Consumer Aspect (multiroom.html)
three. Initially we insert a fall down While using the listing of server rooms.
4. Next we prefabricated vaults contact the server side changeRoom() function when the user first connects and whenever the drop down is changed.
// on creating 'now' relationship, established the server home
now.Completely ready(purpose()
// By default decide the 1st chatroom
now.changeRoom($('#server-place').val());
);
// On transform of fall down, obvious text and change server space
$('#server-room').change(perform()
$("#messages").html(");
now.changeRoom($('#server-space').val());
);
5. For extra credit, we could enable the server to dynamically present the listing of rooms once the consumer connects.