Simple JS queue with auto run for node and browsers
npm install js-queue js-queue also exposes the easy-stack stack via require('js-queue/stack.js') this file exposes an ES6 stack which allows for Last In First Out (LIFO) queuing. This can come in handy depending on your application needs, check out the easy-stack javascript documentation it follows the js-queue interface but is node 6 or greater as it uses ES6 classes.
javascript
var Queue=require('js-queue');
//create a new queue instance
var queue=new Queue;
for(var i=0; i<50; i++){
//add a bunch of stuff to the queue
queue.add(makeRequest);
}
function makeRequest(){
//do stuff
console.log('making some request');
this.next();
}
`
$3
The only difference is including via a script tag instead of using require.
`html
`
$3
This allows you to start adding requests immediately and only execute if the websocket is connected. To use in plain browser based JS without webpack or browserify just replace the requires with the script tag.
`javascript
var Queue=require('js-queue');
//ws-share just makes it easier to share websocket code and ensure you don't open a websocket more than once
var WS=require('ws-share');
//js-message makes it easy to create and parse normalized JSON messages.
var Message=require('js-message');
//create a new queue instance
var queue=new Queue;
//force stop until websocket opened
queue.stop=true;
var ws=null;
function startWS(){
//websocket.org rocks
ws=new WS('wss://echo.websocket.org/?encoding=text');
ws.on(
'open',
function(){
ws.on(
'message',
handleResponse
);
//now that websocket is opened allow auto execution
queue.stop=false;
queue.next();
}
);
ws.on(
'error',
function(err){
//stop execution of queue if there is an error because the websocket is likely closed
queue.stop=true;
//remove remaining items in the queue
queue.clear();
throw(err);
}
);
ws.on(
'close',
function(){
//stop execution of queue when the websocket closed
queue.stop=true;
}
);
}
//simulate a lot of requests being queued up for the websocket
for(var i=0; i<50; i++){
queue.add(makeRequest);
}
var messageID=0;
function handleResponse(e){
var message=new Message;
message.load(e.data);
console.log(message.type,message.data);
}
function makeRequest(){
messageID++;
var message=new Message;
message.type='testMessage';
message.data=messageID;
ws.send(message.JSON);
this.next();
}
startWS();
`
Extending Queue
`javascript
var Queue=require('js-queue');
//MyAwesomeQueue inherits from Queue
MyAwesomeQueue.prototype = new Queue;
//Constructor will extend Queue
MyAwesomeQueue.prototype.constructor = MyAwesomeQueue;
function MyAwesomeQueue(){
//extend with some stuff your app needs,
//maybe npm publish your extention with js-queue as a dependancy?
Object.defineProperties(
this,
{
isStopped:{
enumerable:true,
get:checkStopped,
set:checkStopped
},
removeThirdItem:{
enumerable:true,
writable:false,
value:removeThird
}
}
);
//enforce Object.assign for extending by locking down Class structure
//no willy nilly cowboy coding
Object.seal(this);
function checkStopped(){
return this.stop;
}
function removeThird(){
//get the queue content
var list=this.contents;
//modify the queue content
list.splice(2,1);
//save the modified queue content
this.contents=list;
return this.contents;
}
}
``