syncs-node

syncs-browser

A JavaScript Library for Real-Time Web Applications

syncs-node is NodeJs module to work with Syncs.

Initalization

syncs-node is easy to setup.

  npm i syncs-node -S

Syncs classes are generated using TypeScript. TypeScript files are also published in npm package, so developers can write both server and client application using typescript.

JavaScript Initialize:

  let Syncs=require('syncs-node').Syncs;
  let io=new Syncs("ws//server-addserss/syncs");

TypeScrip Initialize using default export:

  import syncs from "syncs-node";
  let io=syncs("ws//server-addserss/syncs");

TypeScrip Initialize using Syncs class:

  import {Syncs} from "syncs-node";
  let io=new Syncs("ws//server-addserss/syncs");

The path parameter is required that determines Syncs server address. The second parameter is Syncs configs object with following properties:

• autoConnect:boolean: If autoConnect is false then the Syncs instance will not connect to server on creation. To connect manuly to server developers should call io.connect() method. default value is true.
• autoReconnect:boolean: This config makes the connection presistent on connection drop. default value is true.
• reconnectDelay: number: time to wait befor each reconnecting try. default value is 10000.
• debug:bolean: This parameter enables debug mode on client side. default value is false.

Handling connection

Syncs client script can automatically connect to Syncs server. If autoConnect config is set to false, the developer should connect manualy to server using connect method.

Using connect method developers can connect to defined server.

  io.connect();

Target application can establish connection or disconnect from server using provided methods.

  io.disconnect()

Developers can handle disconnect and close event with onDisconnect and onClose method.

    io.onDisconnect(()=>{
            
    })

    io.onClose(()=>{
            
    })

It's alos possible to check connection status using online property of Syncs instance.

  if(io.online){
      //do semething
  }

Abstraction Layers

Syncs provides four abstraction layer over its real-time functionality for developers.

1. onMessage Abstraction Layer

Developers can send messages using send method of Syncs instance to send JSON message to the server.Also all incoming messages are catchable using onMessage.

io.onConnection(client=>{
    io.send({text:"im ready"});
})

io.onMessage(message=>{
    alert(message.text);
})

2. Publish and Subscribe Abstraction Layer

With a Publish and Subscribe solution developers normally subscribe to data using a string identifier. This is normally called a Channel, Topic or Subject.

 io.publish('mouse-move-event',{x:xLocation,y:yLocation});

 io.subscribe('weather-update',updates=>{
   // update weather view
 });

### 3. Shared Data Abstraction Layer Syncs provides Shared Data functionality in form of variable sharing. Shared variables can be accessible in tree level: Global Level, Group Level and Client Level. Only Client Level shared data can be write able with client.

To get Client Level shared object use shared method of Syncs instance.

  let info=io.shared('info');
  info.title="Syncs is cool!"

To get Group Level shared object use groupShared method of Syncs instance. First parameter is group name and second one is shared object name.

  let info=io.groupShared('vips','info');
  document.title=info.onlineUsers+" vip member are online";

To get Global Level shared object use globalShared method of Syncs instance.

  let settings=io.globalShared('settings');
  applyBackground(settings.background);

It's possible to watch changes in shared object by using shared object as a function.

  info((event)=>{
    document.title=info.title
  });

The callback function has two argument.

• values:object: an object that contains names of changed properties and new values.
• by:string a string variable with two value ( 'server' and 'client') which shows who changed these properties.

4. Remote Method Invocation (RMI) Abstraction Layer

With help of RMI developers can call and pass argument to remote function and make it easy to develop robust and web developed application. RMI may abstract things away too much and developers might forget that they are making calls over the wire.

Before calling remote method from server ,developer should declare the function on client script.

functions object in Syncs instance is the place to declare functions.

io.functions.showMessage=function(message) {
  alert(message);
}

To call remote method on server use remote object.

  io.remote.setLocation(latitude,longitude)

The remote side can return a result (direct value or Promise object) which is accessible using Promise object returned by caller side.

    io.functions.askName=function(title){
        return prompt(title);
    }

io.functions.startQuiz=function(questions,quizTime){
    return new Promise((res,rej)=>{
        // start quiz
        setTimeout(()=>{
            res(quizResult);
        },quizTime);
 
    })
}

  io.remote.getWeather(cityName).then(forcast=>{
      // show forcast result
  })