How to implement queue in angular?

typescript queue
angular queue http requests
implement queue using stacks javascript
implement queue in node js
rxjs queue
angular job queue
rxjs queue http requests
rxjs message queue

image description:

clicking on an icon will do its action after icons task completed, it should get terminated. but some icons can stay active in combination with other icons.


I have more than 30 options to work with. I want to track all the items. whenever an item is clicked, it should be inserted. and when clicked again it should be removed. if an item is already active, and if it is clicked again, then it should be removed. some options are like they can stay with other combinations of options.

What I did till now:

I implemented two methods for this, execute and terminate to do insertion and removal of last clicked item. If I'll go with the same process, then there will be a lot of if else, which I don't want to implement. I thought to implement a queue, which will help me in tracking all the options selected by the user.

How to implement a queue in angular 5 or more? If there is any other better approach I can go through, suggest me.

Any help will be much appreciated.

I found a solution. Please try it

Create a Class

 export class Queue<T> {
  _store: T[] = [];
  public push(val: T) {
  public pop(): T | undefined {
    return this._store.shift();

You can pass any type to T Parameter of the class. It's a Class Constraint

and here is my demo class for passing as Parameter to Queue

export class Demo{

    public val1:number;
    public val2:string;


How to use it

    let Qu:Queue<Demo>  = new Queue<Demo>();
    Qu.push({val1:1, val2:"Asanga1"});
    Qu.push({val1:2, val2:"Asanga2"});


Here is the out put in console

>Object {val1: 1, val2: "Asanga1"}

So it pull out the first one in the queue

Please try it .

How to prioritize certain HTTP requests from a Queue: Angular (2+) , For me to talk about a Queue like implementation for the Interceptor, the use-case that I stumbled upon is as follows. Queue multiple files for uploading with Angular and ASP.NET Core 2.1 implement it and the job is done. (I will show you in an upcoming article how to track progress and list uploading

JavaScript ES6 provides implementations to Queue and Stack datastructures out of the box using the Array object.

Please refer to this post.

To get the benefit of Angular types, use the Array<T> interface.

jseppi/angular-queue: Processing queue for AngularJS, Usage. Include angular-queue.js after your main AngularJS script. View all of  Suppose, if we have a long running task, which requires 10 seconds to complete processing, then we can queue up this task for later, using Microtask queues (for more details, click here). This article is written for Knockout framework but is still worth reading to understand the concept of Microtask.

Here is a quick implementation of a queue in TypeScript. You can modify it to use in Javascript.

class Node<T> {
  next: Node<T>;
  constructor(public data: T) {

export class Queue<T> {
  head: Node<T>;
  tail: Node<T>;

  constructor() {
    this.head = this.tail = null;

  enqueue(data: T): void {
    const node = new Node(data);

    if (this.isEmpty()) {
      this.head = this.tail = node;
    } = node;
    this.tail = node;

  dequeue(): T {
    if (this.isEmpty()) {
      return null;

    const data =;

    if (this.tail === this.head) {
      this.head = this.tail = null;
    } else {
      this.head =;

    return data;

  isEmpty() {
    return this.head === null;

Implementation of Queue in Javascript, In This article, we would be implementing Queue data structure in javascript. A Queue works on the FIFO(First in First Out) principle. Hence, it performs two basic​  Angular — A Beginner’s Guide to Design and Implementation of an Angular App. If you are a beginner for Angular and wonder how to start, This article is for you and we focus only on basic

Queue in JavaScript:

// initialization
const queue = []
// insertion
queue.unshift(/* element here */)
// removing
const removedElement = queue.shift()
// first element
const firstElement = queue[0]
// last element
const lastElement = queue[queue.length - 1]

Implement Stack and Queue using Deque, Deque also known as double eneded queue, as name suggests is a special kind of queue in which insertions and deletions can be done at the last as well Queue using Stacks. The problem is opposite of this post. We are given a stack data structure with push and pop operations, the task is to implement a queue using instances of stack data structure and operations on them. A queue can be implemented using two stacks. Let queue to be implemented be q and stacks used to implement q be stack1 and stack2. q can be implemented in two ways:

Easily Implement Stacks (Fifo) And Queues (Lifo) With , I'm currently reviewing Javascript basis for a personnal project and it appears I often use stacks and queues implicitly. Let's make it explicit and easyer to  Angular Component is used to present data and delegate data access to a service. Angular Services are a great way to share data among classes. So in the tutorial, we introduce how to create Angular Service and use Observable class of RxJS library for asynchronous operation in Angular Service’s implementation.

The Little Guide of Queue in JavaScript, Implementation. So the first thing that we are going to do is create a Queue constructor function with a empty array inside. function Queue() { In this article, we are going to learn how the services in Angular are being created and used. We will also learn why we create services and how we achieve dependency injection in Angular. Prerequisites. HTML, CSS, and JS; Basics of TypeScript. Note See my previous article “Services in Angular” and create the application using Services.

Javascript Data Structures - Stacks, Queue and Deque, Stacks, queues and deques are the most basic of the slightly more The good news is that they are very, very easy to implement in JavaScript. PriorityBlockingQueue is one alternative implementation if thread safe implementation is needed. Few important characteristics of Queue are: Few important characteristics of Queue are: The Queue is used to insert elements at the end of the queue and removes from the beginning of the queue.

  • Any way you can put this on codepen to get a better understanding of what you're trying to do?
  • How would you implement a queue in JavaScript? It would really just be an array with unshift(), pop(), and some custom methods? In Angular you'd probably iterate over that array with *ngFor. What have you tried so far specifically?
  • Shift/unshift method is costly in terms of performance, if I am not wrong. So, I am trying to avoid array.
  • Yes you are wrong and you are only doing this occasionally when a user interaction event occurs
  • @charlietfl, it's not occasional sir. I am using for commands. a user can click on any commands present on the webpage. for example- menu commands in an explorer window. most of the things will be available on this webpage as well.
  • will it work in multi-tab scenario ?