This time I will bring you a detailed explanation of the use of Rxjs. What are the precautions when using Rxjs? The following is a practical case, let’s take a look.
During the execution of an observable object, zero to infinite next notifications are sent. If an Error or Complete notification is sent once, no value will be sent thereafter.
The observable object strictly adheres to this contract, so the following code will not send a next notification containing the value 4
var observable = Rx.Observable.create(function subscribe(observer) { observer.next(1); observer.next(2); observer.next(3); observer.complete(); observer.next(4); // Is not delivered because it would violate the contract});
A good way is to wrap it with a try/catch statement Notification statement, if an exception is caught, an error notification will be sent.
var observable = Rx.Observable.create(function subscribe(observer) {try { observer.next(1); observer.next(2); observer.next(3); observer.complete(); } catch (err) { observer.error(err); // delivers an error if it caught one} });
Unsubscribe unsubscribe()
Since the execution of observable objects may be infinite (continuous next), observers often want to terminate within a limited time execution, so we need an API to cancel the execution.
var observable = Rx.Observable.from([10, 20, 30]);var subscription = observable.subscribe(x => console.log(x));// Later:subscription.unsubscribe ();
After you subscribe, you will get a Subscription object, which represents the ongoing execution. Feel free to use unsubscribe() to terminate execution.
observerObserver
What is an observer? Observers are consumers of data sent by observable objects. Simply put, observers are a set of callback functions, which respectively correspond to a type of notification sent by the observable object: next, error and complete. The following is an example of a typical observer object:
var observer={next:x=>console.log('Observer got a next value: ' + x),error: err => console.error('Observer got an error: ' + err),complete: () => console.log('Observer got a complete notification') }
An observer is just an object composed of three callback functions Array. Each callback function corresponds to the notification type of the observable object.
Subscription Subscription
Subscription objects can also be placed together, so calling unsubscribe() on one subscription object can cancel multiple subscriptions. The method is: "add" one subscription to another subscription.
var observable1 = Rx.Observable.interval(400);var observable2 = Rx.Observable.interval(300);var subscription = observable1.subscribe(x => console.log('first: ' + x));var childSubscription = observable2.subscribe(x => console.log('second: ' + x)); subscription.add(childSubscription); setTimeout(() => {// Unsubscribes BOTH subscription and childSubscriptionsubscription.unsubscribe(); }, 1000);
After execution, we can get in the console:
second: 0 first: 0 second: 1 first: 1 second: 2
Subscription also has a remove(otherSubscription) method, which is used to cancel the sub-subscription added by add.
I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to the php Chinese website Other related articles!
Related reading:
Detailed explanation of the use of js-xlsx tool library xlsxUtils
Integration of daily common functions of JS
The above is the detailed content of Detailed explanation of the use of Rxjs. For more information, please follow other related articles on the PHP Chinese website!

Python and JavaScript each have their own advantages, and the choice depends on project needs and personal preferences. 1. Python is easy to learn, with concise syntax, suitable for data science and back-end development, but has a slow execution speed. 2. JavaScript is everywhere in front-end development and has strong asynchronous programming capabilities. Node.js makes it suitable for full-stack development, but the syntax may be complex and error-prone.

JavaScriptisnotbuiltonCorC ;it'saninterpretedlanguagethatrunsonenginesoftenwritteninC .1)JavaScriptwasdesignedasalightweight,interpretedlanguageforwebbrowsers.2)EnginesevolvedfromsimpleinterpreterstoJITcompilers,typicallyinC ,improvingperformance.

JavaScript can be used for front-end and back-end development. The front-end enhances the user experience through DOM operations, and the back-end handles server tasks through Node.js. 1. Front-end example: Change the content of the web page text. 2. Backend example: Create a Node.js server.

Choosing Python or JavaScript should be based on career development, learning curve and ecosystem: 1) Career development: Python is suitable for data science and back-end development, while JavaScript is suitable for front-end and full-stack development. 2) Learning curve: Python syntax is concise and suitable for beginners; JavaScript syntax is flexible. 3) Ecosystem: Python has rich scientific computing libraries, and JavaScript has a powerful front-end framework.

The power of the JavaScript framework lies in simplifying development, improving user experience and application performance. When choosing a framework, consider: 1. Project size and complexity, 2. Team experience, 3. Ecosystem and community support.

Introduction I know you may find it strange, what exactly does JavaScript, C and browser have to do? They seem to be unrelated, but in fact, they play a very important role in modern web development. Today we will discuss the close connection between these three. Through this article, you will learn how JavaScript runs in the browser, the role of C in the browser engine, and how they work together to drive rendering and interaction of web pages. We all know the relationship between JavaScript and browser. JavaScript is the core language of front-end development. It runs directly in the browser, making web pages vivid and interesting. Have you ever wondered why JavaScr

Node.js excels at efficient I/O, largely thanks to streams. Streams process data incrementally, avoiding memory overload—ideal for large files, network tasks, and real-time applications. Combining streams with TypeScript's type safety creates a powe

The differences in performance and efficiency between Python and JavaScript are mainly reflected in: 1) As an interpreted language, Python runs slowly but has high development efficiency and is suitable for rapid prototype development; 2) JavaScript is limited to single thread in the browser, but multi-threading and asynchronous I/O can be used to improve performance in Node.js, and both have advantages in actual projects.


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Dreamweaver Mac version
Visual web development tools

DVWA
Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software

Dreamweaver CS6
Visual web development tools

SublimeText3 Linux new version
SublimeText3 Linux latest version

Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.
