Questions tagged [singleton]

Singleton is a uniqe creational design pattern popularized by the Gang of Four, which guarantees the existence of only one instance of a specific class throughout the entire application. You can employ this tag for any inquiries related to the singleton design pattern. However, it should not be used for questions that involve elements of the singleton pattern but do not revolve around it in entirety.

Can NgZone be utilized within a shared service instance?

I am currently working on creating an injectable singleton service for my application that will provide all components with information about the window width and height, as well as notify them when the page is scrolled or resized. Below is the code snipp ...

The pivotal Angular universal service

In my application, I have the need to store global variables that are specific to each user. To achieve this, I created a Service that allows access to these variables from any component. However, I am wondering if there is a way to share this service t ...

angular typescript singleton

Should you consider using the Singleton pattern in Node.js applications?

After stumbling upon this specific piece discussing the creation of a singleton in Node.js, it got me thinking. The require functionality according to the official documentation states that: Modules are cached after the first time they are loaded. Multi ...

javascript node.js design-patterns singleton

Prefixes for logging - Consider using the not-singleton technique or another approach

I am currently developing a logging helper for Node.JS that includes several exported functions such as error and warn. For instance, I have two other scripts called test1 and test2 which make use of this "module". When initializing my logging module us ...

javascript node.js ecmascript-6 singleton

Angular 6 Subscription Service Does Not Trigger Data Sharing Events

Is there a way to set a value in one component (Component A) and then receive that value in another component (Component B), even if these two components are not directly connected as parent and child? To tackle this issue, I decided to implement a Shared ...

angular typescript callback singleton angular-components

Singleton constructor running repeatedly in NextJS 13 middleware

I'm encountering an issue with a simple singleton called Paths: export default class Paths { private static _instance: Paths; private constructor() { console.log('paths constructor'); } public static get Instance() { console.log(this._ins ...

javascript typescript next.js singleton

Injecting Dependencies in Angular 2 Without Using the Constructor

Exploring DI in Angular 2 has led me to implement a REST-Client using generic subtypes for concrete Datatypes like this: class RESTClient<T>{ constructor() { var inj = ReflectiveInjector.resolveAndCreate([HTTP_PROVIDERS]); this. ...

angular typescript dependency-injection singleton

The concept of a singleton design pattern is like a hidden treasure waiting to be

My approach to implementing the singleton pattern in a typescript ( version 2.1.6 ) class is as follows: export class NotificationsViewModel { private _myService: NotificationService; private _myArray: []; private static _instance: Notificatio ...

typescript design-patterns singleton nativescript

Creating a shared singleton instance in Typescript that can be accessed by multiple modules

Within my typescript application, there is a Database class set up as a singleton to ensure only one instance exists: export default class Database { private static instance: Database; //Actual class logic removed public static getInstance() ...

javascript node.js typescript singleton

Only the final defined document is instantiated by the Swagger-ui-express module

Currently, I am working on a Typescripted nodejs server and facing an issue with defining different swagger paths for separated controllers. The problem is that the swagger-ui-express module only displays the last defined document in the specific route. I ...

node.js typescript singleton swagger swagger-ui

Two instances of a PHP Class created despite employing the Singleton design pattern

Object Oriented PHP Class: if( ! class_exists('MY_CLASS') ) : class MY_CLASS { private static $_instance = null; private static $counter = 0; private function __construct() { self::$counter++; // Perform actions here. ...

php singleton instance

Struggling to implement a singleton service in Angular as per the documentation provided

I have implemented a service in Angular that I want to be a singleton. Following the guidelines provided in the official documentation, I have set the providedIn property to "root" as shown below: @Injectable({ providedIn: "root" }) export class SecuritySe ...

angular typescript dependency-injection singleton angular8

Singleton pattern for iFrames sharing the same origin

I have developed a web application that runs on multiple iframes within a parent window, similar to a modified version of GWT. Rather than each individual iframe accessing our backend service separately, I am attempting to have them share the data service ...

javascript iframe singleton

Angular 7's Singleton Service Feature

My service setup looks like this: export abstract class ILoggingService { // abstract functions here } export class LoggingService implements ILoggingService { // service implementation } export class MockLoggingService implements ILoggingServic ...

angular typescript singleton

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