Intersection observer js example. getBoundingClientRect() method.



Intersection observer js example. It's highly efficient for detecting when an element becomes visible or hidden, making it ideal for scroll-based animations. It’s far more performant than using a scroll event listener with the Element. It is setup like this: const el = document. No external JavaScript or CSS libraries used in examples Jun 24, 2025 · The observe() method of the IntersectionObserver interface adds an element to the set of target elements being watched by the IntersectionObserver. Mar 23, 2024 · Through practical examples, you'll learn how to use IntersectionObserver to lazy load images, videos, and other content. May 7, 2021 · We’re going to create an example using the Intersection Observer API with React because it’s a popular and frequently used JavaScript UI library. Does anybody have any idea how cou Jun 24, 2025 · If root is null, then the owning document is used as the root, and the bounds its viewport (that is, the visible area of the document) are used as the root bounds. Jan 5, 2023 · January 5, 2023 / #Next. Understand the core concepts, practical applications, and performance considerations for efficient web development. js styles. Intersection Observer API is one of the most underutilized and unheard JavaScript's features. Aug 8, 2025 · Intersection observer The v-intersect directive utilizes the Intersection Observer API. js app using the Intersection Observer API. May 31, 2023 · While figuring out if an element was in view used to require quite a bit of math and performance draining scroll listeners, the Intersection Observer API makes the task quite a bit simpler and Jun 1, 2021 · In this blog post we’ll be seeing how to use the intersection observer API from the browser to create an infinite scrolling list by observing when a specific element is being displayed and making a get request to an external API to show more data to users. Jan 2, 2020 · The Intersection Observer API is probably one of the most useful Web APIs that have been released recently. As the user scrolls down, triggering the intersection of the sentinel element with the viewport, more items are dynamically loaded. Well, what are these “Observers”? Feb 9, 2023 · The Intersection Observer vs Other Observer APIs In addition to the Javascript Intersection Observer, there are two other observer APIs: The Resize Observer and the Mutation Observer. js app using React Intersection Observer and Tailwind CSS. I tried creating multiple observers, Nov 21, 2019 · I am currently using the intersection observer to detect when an element leaves the viewport. Makes sense. A polyfill for IntersectionObserver. Jul 25, 2023 · With the react-intersection-observer package, we can create a dynamic header and improve the navigation experience within content-rich pages. In Javascript, performing an action Jul 29, 2024 · Intersection Observer is an API that is used to detect the interaction of a target element with its's ancestor element or the document viewport. By using the built-in React hooks, we can handle all the intersection observer functionality with ease. Improve site performance and user experience. Practical, real world React examples of IntersectionObserver APIExamples use only IntersectionObserver API. Feb 20, 2024 · Explore 3 use cases for working with the React Intersection Observer: lazy loading, infinite scrolling, and animation/transition triggers. I am able to verify that my mock observe jest function is being called once. Jul 23, 2025 · 🚀 Today I Learned: Intersection Observer API in JavaScript 👨‍💻 As a developer, I'm always looking for ways to improve performance and user experience — and today I explored something incredibly useful: the Intersection Observer API. I can enable this when the page loads or when the server-rendered HTML for the component is scrolled into view (Astro uses the Intersection Observer API). Nov 2, 2020 · In this example, we will use the intersection observer to check the visibility of a container div on a web page. ” Jul 29, 2025 · The IntersectionObserver interface of the Intersection Observer API provides a way to asynchronously observe changes in the intersection of a target element with an ancestor element or with a top-level document's viewport. Performance will get really choppy. May 25, 2020 · Intersection Observer Using Intersection Observer we can observe the visibility change of an element (target) in the viewport (screen visible area). It is different than a click callback or a scroll callback because this callback will be fired every single time that it needs to check if something is running on the page. These methods can be used together, like this: Jan 19, 2025 · Recently while exploring the frontend world, I came upon a interesting feature of JavaScript -> Intersection Observer. An intersection observer can observe as many elements as one desires using the observe() method as we shall see later on. Unlike the traditional methods such as scroll events, the Intersection Observer makes handling element visibility simple, efficient, and less taxing on performance. Sep 4, 2024 · The Intersection Observer API opens up new possibilities for creating immersive scroll experiences. Oct 30, 2019 · I want intercep an intersection when the target element is at 100px from the intersection root for make it, i have setted rootMargin with '100px 0px 100px 0px'. Intro The Intersection Observer API provides a way to asynchronously observe changes in the intersection of a target element with an ancestor element or with a top-level document's The intersection observer is going to take a callback, which is a function that gets called at a certain point. Follow our step-by-step guide with code examples. Aug 30, 2017 · A Vue component to add intersection-observer to a Vue component or HTML element. Feb 9, 2022 · Intersection Observer — The Simplest Way to Animate Your Website on Scroll Thanks to this gem of an API, most of the legwork is done for you when trying to calculate the position of your element on … Aug 1, 2020 · Intersection Observer: what is it? The Intersection Observer API is a relatively new functionality in web browsers that can allows us to listen to events when an element’s visibility on the page changes. The solutions using scroll events always have issues similar to using scroll events for other purposes. Sep 24, 2019 · I’ve seen examples of having an event of sorts for sticky positioning using both scroll events and the Intersection Observer. The IntersectionObserver method observe() adds an element to the set of target elements being watched by the IntersectionObserver. 2 days ago · The Intersection Observer API provides a way to asynchronously observe changes in the intersection of a target element with an ancestor element or with a top-level document's viewport. Apr 23, 2023 · Using browser native solutions like the Intersection Observer API helps reduce load time and decreases the number of dependencies in your project. You'll need to complete a few actions and gain 15 reputation points before being able to upvote. " Replace document. Aug 7, 2025 · If you’re a JavaScript developer, you’ve probably heard of the term Intersection Observer, but what exactly is it, and how can it make your web apps faster and more efficient? In this post, we Nov 21, 2019 · In this article, I’ll show you how to create a basic Intersection Observer that will add or remove a CSS blur when an object has entered or left the viewport. In this post, we'll dive into how to use the IntersectionObserver API in May 7, 2019 · What Is the Intersection Observer API? In short, it enables you to detect the visibility of an element, i. This is also used for the v-lazy component. Intersection Observer can be considered more performant than listening for scroll events on the main thread, as it is asynchronous, and the callback will only fire Jul 27, 2025 · When the page loads, the initial set of items is loaded. Feb 6, 2021 · The Intersection Observer (IO) detects when an element enters or leaves the viewport (or a parent ele Tagged with tutorial, codenewbie, javascript, css. Intersection Observer Example Edit the code to make changes and see it instantly in the preview Explore this online Intersection Observer Example sandbox and experiment with it yourself using our interactive online playground. e. Talking about the name of the API, the word 'intersection' comes from the fact that this API only looks for intersections i. However, you can easily use the Intersection Observer API with any framework or library you want. How Intersection Observer API Works The Intersection Observer API provides a performant, efficient way to detect visibility changes to target elements relative to ancestors or viewport edges. Here is a simple example that checks when the user has reached the end of the page: Apr 21, 2024 · In this in-depth tutorial, we‘ll explore how to implement infinite scroll in a Next. They provide the backbone for building dynamic, interactive applications. . Thanks to Angular's directives, we can create a reusable way to use this API in a declarative and easy way. Example: Below is an example to implement Infinite Scroll using JavaScript Intersection Observer API: May 22, 2021 · Well, JavaScript has a native Intersection Observer API that lets you do just that and much, much more. For example, if we want to detect if some element is visible in the viewport we can use this API for that purpose. Jul 12, 2020 · “The Intersection Observer API provides a way to asynchronously observe changes in the intersection of a target element with an ancestor element or with a top-level document’s viewport. Additional ressources Google article Infinite Scrolling example Explainer Doc Specs Quick introduction to the Intersection Observer API Dec 13, 2024 · The Intersection Observer API provides a way to asynchronously observe changes in the intersection of a target element with an ancestor element or with a top-level document's viewport. takeRecords() – gets a list of unprocessed mutation records – those that happened, but the callback has not handled them. When it detects an intersection, the observer function fires a callback function that tells the code what to do next. Jul 29, 2025 · Examples This example creates a new intersection observer which calls the function myObserverCallback every time the visible area of the element being observed changes by at least 10%. This tutorial demonstrates how to implement such effects using vanilla JavaScript and React. Each side of the rectangle represented by rootMargin is added to the corresponding side in the root element's bounding box before the intersection test is performed. Mar 14, 2023 · Basic knowledge of JavaScript. The most important use case of Intersection Apr 4, 2023 · Learn how to build ScrollSpy Javascript in this complete guide. In the following example, we use it to trigger an animation when the target enters the viewport. The code is roughly like so: // get an element const thingIWantEntirelyInView = $("# Jan 16, 2025 · Observers are an essential pattern in JavaScript, enabling developers to monitor and respond to changes in objects, events, or data streams. It is used to monitor the visibility of a specific element. It provides an easy-to-use interface for detecting when elements are visible within the user’s viewport. The provided code examples and step-by-step Apr 23, 2024 · The Intersection Observer API is a great tool for implementing parallax, as it can track the visibility of background and foreground elements and adjust their positions or speeds accordingly as the user scrolls. While there are many libraries out there for intersection animations, you can also use the INTERSECTION OBSERVER API in JavaScript. if it’s in the current viewport, and also the relative visibility of two elements in Feb 6, 2025 · The Intersection Observer API is a powerful tool for detecting changes in the visibility of an element relative to a viewport or a parent element. One of its exciting use cases is creating smooth and visually appealing scroll-and-snap effects. Upvoting indicates when questions and answers are useful. The second observer is looking for the #review-form section and upon intersection, the button changes text content from 'Leave a Review' to 'Scroll to Top'. Mar 27, 2024 · Understanding the IntersectionObserver API syntax The IntersectionObserver API works by creating an observer object that is tied to a specific element on the page. Sounds good, right? Let’s deep dive into intersection observers. css Jul 23, 2025 · 🚀 Today I Learned: Intersection Observer API in JavaScript 👨‍💻 As a developer, I'm always looking for ways to improve performance and user experience — and today I explored something incredibly useful: the Intersection Observer API. Quick Example with a load more on Scroll Implementation Jul 16, 2023 · There does not currently seem to be a way to detect if an element is being observed. It is a powerful feature that can be used to improve your JavaScript applications. js How to Implement Infinite Scroll in Next. 🧠 Why It's Awesome Instead of relying on expensive scroll event listeners, the Intersection Observer API provides a modern, efficient way to detect Sep 21, 2024 · Everything you need to know to start using the JavaScript intersection observer API in your projects. js using the Intersection Observer API and TypeScript is clear and concise. We‘ll cover the key concepts, walk through a full code example, and discuss best practices and potential pitfalls. The API keeps track of intersection between two elements in a webpage. js with Intersection Observer By Divine Orji Creators and developers continually come up with new ways to enhance apps and provide value to users. getBoundingClientRect() method. You can use it as a template to jumpstart your development with this pre-built solution. We'll start by briefly covering the basics of the Intersection Observer API and its benefits. The answer lies in leveraging the Intersection Observer API – a modern, efficient technique to detect when an element enters or exits the viewport. Intersection Observer Flow Diagram Aug 2, 2023 · We can now dive into the details. Basic Implementation Here's a simple example of how to create and use an Intersection Observer: Intersection Observer Intersection Observer API which is my favorite observer in the list. Jun 15, 2023 · Great article, Satyam! Your explanation of lazy loading components in Next. Feb 15, 2019 · Intersection Observer v2 adds the capability to not only observe intersections per se, but to also detect if the intersecting element was visible at the time of intersection. Feb 17, 2018 · An example of using the Intersection Observer API to build a lazy loaded image component in Vue. Apr 20, 2016 · IntersectionObservers let you know when an observed element enters or exits the browser&#39;s viewport. Jun 24, 2025 · Learn how the JavaScript IntersectionObserver API detects visibility changes for elements in the viewport. Apr 26, 2021 · } Intersection Observer for single element I would not suggest using this approach if you want to observer multiple elements. In this article I will cover all the basics of Intersection Observer as well as the more complex Our callback is invoked with the entries argument by the observer. Code snippets and example using Vanilla JS Jul 1, 2024 · The Intersection Observer API is a web API that allows you to asynchronously observe changes in the intersection of a target element with an ancestor element or the viewport. we can control the element’s loading and animations based on the target element’s visibility and positions. Examples This example sets the border of the intersection observer's root element to be a 2-pixel medium green line. In this article, we will discuss how this Intersection Observer API works and how we can use it to detect the visibility of an element by building a simple web page that implements this "reveal contents on scroll" feature. There are 1288 other projects in the npm registry using react-intersection-observer. Feb 9, 2023 · The Intersection Observer vs Other Observer APIs In addition to the Javascript Intersection Observer, there are two other observer APIs: The Resize Observer and the Mutation Observer. What is Intersection Observer? The Intersection Observer API provides a way to asynchronously observe changes in the intersection of a target element with an ancestor element or with the top-level document's viewport. This API allows you to observer intersections of elements, and Feb 22, 2025 · The Intersection Observer API provides a way to observe when elements enter or leave the viewport, making it perfect for implementing lazy loading, infinite scrolling, and scroll-based animations. Intersection Observer in my opinion is the most useful because of how easy it makes things like infinite scrolling, lazing loading images, and scroll based animations. 0 and 1. Jan 13, 2024 · Creating an infinite scroll for a webpage using Intersection Observer and an API is a common task in web development. Sep 13, 2020 · observer. This callback provides entries, which are objects containing information about each observed target element and its intersection status. In this article, I'll explain exactly what the Intersection Observer does, how it works and why it should be an essential tool in your development toolkit. The following is an example of a typical Observer object: Feb 9, 2024 · Infinite Scroll Using JavaScript’s Intersection Observer API Hey there!! We all have visit web sites and have encountered that the data on websites loads as we scroll down the page. In this example the intersection b Is there a way to detect if an element leaves the viewport using Intersection Observers? For example, I have an element on the screen that I want to fire a callback when the top of the element hits Use this online intersection-observer playground to view and fork intersection-observer example apps and templates on CodeSandbox. You can read more about Intersection Observer here. One observer has one set of thresholds and one root, but can watch multiple target elements for visibility changes in keeping with those. Upon intersection, a button shows to scroll down the #review-form section. The ancestor element or viewport is referred to as the root. Learn it now! Apr 23, 2022 · I have an Intersection Observer working for an element on the page, however I want to now apply a completely different animation to another element on the page. What is the Intersection Observer API? The intersection observer API allows your code to observe or monitor changes based on how a particular target element intersects with an ancestor or root element. On click, scroll to 0,0. Jul 18, 2024 · In this blog, we'll explore how to use the Intersection Observer API to improve your website's performance. What would happen now is that, because their intersection ratios have both become equal to the threshold value 1, they both will show up in the entries Jun 16, 2025 · What Is Intersection Observer? The Intersection Observer API lets you asynchronously observe changes in the intersection of a target element with an ancestor element or with the viewport. Contribute to GoogleChromeLabs/intersection-observer development by creating an account on GitHub. Mar 23, 2023 · Intersection Observer first watches for an intersection (either between two elements or an element and the browser’s viewport). It will observe changes in the intersection of a target element with an ancestor element. This lets you, for example, adjust the bounds outward so that the target element is This is a quick and simple examle to show how to make use of the new IntersectionObserver in modern browsers, Jun 5, 2021 · A Beginner's Guide to JavaScript's The Intersection Observer API by David Herbert June 5th, 2021 Dive into our detailed guide on creating a custom Intersection Observer in JavaScript. Aug 24, 2024 · The Intersection Observer is one of the most useful and flexible tools you can use in modern web development. In this comprehensive 3300-word guide, you’ll master implementing performant reveal effects in React using Intersection Observer. Also suppose that upon scrolling the document to some value (like by using the scrollTop property), they both show up in the viewport completely. App. 0. This observer watches for changes in the intersection of the target element with the viewport and triggers a callback function whenever a change is detected. Resize Observer This API consists of the Resize Observer interface, an instance that has 3 methods: the base observe(), disconnect() and the unObserve(). Use-Cases of the Intersection Mar 16, 2025 · The Intersection Observer API is used to asynchronously detect when an element enters or exits a specific container (often the viewport). Sep 6, 2024 · Intersection observer API is a powerful tool in modern web development where we can efficiently detect when an element enters or leaves the viewport or root element. The first intersection observer is looking for the #comments section to intersect. What is Intersection Observer? Intersection Observer is a really awesome JavaScript API that simplifies scroll-based events in JavaScript. Feb 26, 2023 · The Intersection Observer API works by creating an “Intersection Observer” object, that’s configured with options like the root element, threshold, and visibility. In this comprehensive 3200+ word guide for intermediate React developers, we will code a reveal on scroll component from scratch using Intersection Observer. However, implementation in React requires an understanding of its core concepts and integration with hooks. e when an element known as the targetcuts through another element known as the root. Prerequisites Sep 6, 2023 · Introduction Intersection Observer is a JavaScript API that provides an efficient way to Tagged with webdev, javascript, tutorial, beginners. js May 11, 2023 · Understand and Implement Intersection Observer in JavaScript Learn how to use and implement the Intersection Listerner, why it can help you with performance, and much more. Dec 30, 2024 · The Intersection Observer is a modern JavaScript API designed to efficiently detect and respond to the visibility of elements within a viewport or a container. This argument is an array where each item describes the intersection event that caused the callback to be invoked. Jan 14, 2024 · Till this day, if there was a feature of JavaScript that I fell in love with was IntersectionObserver API. Jul 5, 2019 · It's pretty easy to tell with an intersection observer when the entirety of an element in within the viewport. To over come this the simplest solution is to add a flag to an element when you attach the Observer to it. Jun 24, 2025 · The intersectionRatio read-only property of the IntersectionObserverEntry interface tells you how much of the target element is currently visible within the root's intersection ratio, as a value between 0. You'll also learn how to dynamically render components based on their visibility in the viewport. Aug 1, 2023 · Implement lazy loading for videos using Intersection Observer API. Jump ahead within this section: Jan 25, 2023 · Learn how to animate on scroll in your Next. Some key capabilities in relation to infinite scroll: Start using react-intersection-observer in your project by running `npm i react-intersection-observer`. Jul 13, 2021 · The Intersection Observer API is a JavaScript API that enables us to observe an element and detect when it passes a specified point in a scrolling container — often (but not always) the viewport — triggering a callback function. Then, we'll look at a practical example of using it with React to animate a component. Then you can look for this flag in the future when you need to check if it has already been added. Click the link for live demo. What's reputation and how do I get it? Instead, you can save this post to reference later. Feb 15, 2021 · Today we are gonna explore how to use the intersection observer API in React and see some useful exam Tagged with react, webdev, javascript, html. However, I can't figure out how to set up observation with "useEffect". element. It's one of the "new Dec 13, 2024 · The Intersection Observer API is a relatively new addition to the web APIs that tracks changes in the intersection of a target element with an ancestor element or the top-level document's viewport. dataset. Can I also rerender the GUI component accordingly as if it was being rendered in the browser? Basically, check if the component that the intersection observer is observing is not on screen, if so, then rerender that component back on screen? Feb 20, 2023 · How to prevent loading unnecessary content and create Infinite Scroll using Vue. Aug 25, 2024 · Now let‘s examine how Intersection Observer enables building this behavior. 5 days ago · Timing element visibility with the Intersection Observer API In this article, we'll build a mock blog which has a number of ads interspersed among the contents of the page, then use the Intersection Observer API to track how much time each ad is visible to the user. In this tutorial I'll demonstrate how to add Intersection Observer to your Nuxt 3 project in order to trigger a reveal on scroll CSS animation. Let’s create a new Create React App project using the following command: May 15, 2024 · In this article, we'll learn how to use the Intersection Observer API with React, a popular JavaScript library for building user interfaces. In this blog post, we’ll dive deep into the types of observers in JavaScript, complete with detailed explanations and practical examples to help you master their usage. getElementById('flow-landing') with null. When an ad exceeds one minute of visible time, it will be replaced with a new one. Jul 1, 2024 · The Intersection Observer API provides a way to asynchronously observe changes in the intersection Tagged with webdev, javascript, beginners, programming. js and IntersectionObserver API. The good news is that we don't need to rely on any external libraries to use this API with React. Apr 28, 2021 · The Intersection Observer API provides a way to asynchronously observe changes in the intersection of a target element with an ancestor element or with a top-level document’s viewport. Below is a basic example using JavaScript, HTML, and CSS. Sep 25, 2023 · The Intersection Observer API provides a way to asynchronously observe changes in the intersection of a target element with an ancestor element or with a top-level document's viewport. It allows you to easily monitor when a specific element enters or leaves the visible area of the viewport. It helps improve performance by reducing the need for Mar 28, 2024 · In our previous post, we covered the basics of the IntersectionObserver API, including its syntax and common methods. Jul 29, 2020 · This post aims at explaining intersection observer API with examples so that you gain an understanding on how to use them in production sites. Dec 20, 2021 · In the recent times, JavaScript has introduced quite a number of observers and Intersection Observer is one of them. This API eliminates the need for Dec 30, 2023 · The component is still rendered on the server, but the component is “hydrated” (brought to life with Javascript) on the client. I recently started looking into this amazing API and came across some really good resources. The IntersectionObserver interface of the Intersection Observer API provides a way to asynchronously observe changes in the intersection of a target element with an ancestor element or with a top-level document's viewport. The complete quote from MDN is as follows: "The Intersection Observer API provides a way to asynchronously observe changes in the intersection of a target element with an ancestor element or with a top-level document's viewport. One feature that's useful for social media and ecommerce apps in particular is infinite scroll. May 16, 2024 · Observer callback : When the intersection of the target element crosses the specified threshold, the callback function is executed. Creating a dynamic header using the Intersection Observer API To better understand the react-intersection-observer package, we will first explore how detecting element visibility worked before the Intersection Observer API, then take a look at the API’s underlying functionality. You have also successfully built a simple webpage to showcase scroll animations with the API. For the purpose of understanding the above statement, take the root element to be the viewport. Aug 25, 2019 · This article demonstrates using the Javascript Intersection Observer API, instead of measuring scroll position, to perform common visibility detection tasks. Dec 17, 2022 · Intersection observer has been around in JavaScript for a while, but you may not have known about it. This example shows the working of Intersection Observer API. Article covers all important details of coding intersection observer JS. You use the API by instantiating the observer with new IntersectionObserver(callback, options). Dec 12, 2024 · JavaScript's Intersection Observer API provides a powerful, efficient way to do this. Jul 5, 2022 · The Intersection Observer API can observe whether an element is visible, so when using it to complete infinite scrolling, need to add an element to the bottom of the list. How the Intersection Observer API Works A Basic Example For example, say we have an observer with a threshold of [1] and two targets being observed by it. Observers are simply a set of callbacks, one for each type of notification delivered by the Observable: next, error, and complete. querySelector('#el') const observer = new window. Great for lazy loading, animations, and more. An intersection observer observes the DOM element’s visibility and positions. Jun 30, 2021 · Step 4] Add Javascript's intersection observer functionality to detect scroll position Intersection observer basically observes elements that you tell it to. This feature helped improve the performance of the webpage so much by simply requesting the resources only once they entered the viewport. February 4, 2021 An introduction to the vanilla JS Intersection Observer API The Intersection Observer API can be used to observe and element and run a callback function when it enters or leaves the viewport (or another element). libraryNameObserverType = true Jul 21, 2017 · The Intersection Observer API provides a way to asynchronously observe changes in the intersection of a target element with an ancestor element or with a top-level document's viewport. Jan 10, 2022 · Intersection Observer is one of 3 observer based JavaScript APIs with the other two being Resize Observer and Mutation Observer. Feb 1, 2024 · The Intersection Observer is a JavaScript API that enables actions based on the visibility of elements within the viewport. In other words, it tracks the intersection of a designated element with another Mar 24, 2023 · In this article, you have learnt about one of JavaScript's observer-based APIs, the Intersection Observer API. If that element is visible on the page, we will display a text (h1) inside the container. The IntersectionObserver is an amazing API which allows you to observe one or more HTMLElement for when it has entered or left the viewport. We ignored the event in the previous example. Dec 31, 2023 · Intersection Observer is an API provided by browsers. Although many aspects of this example will not Jun 6, 2022 · The Intersection Observer API has been around for a few years now and has pretty good browser Tagged with intersectionobserver, dom, javascript. Jul 23, 2024 · The Intersection Observer API provides a way to asynchronously observe changes in the intersection of a target element with an ancestor element or the viewport. Aug 31, 2022 · Intersection Observer can be used to detect intersections between elements, or between an element and the viewport. Feb 14, 2022 · Intersection observer es una API que permite detectar cuando un elemento entra en una zona visible. Jul 29, 2025 · The rootMargin read-only property of the IntersectionObserver interface is a string with syntax similar to that of the CSS margin property. 🧠 Why It's Awesome Instead of relying on expensive scroll event listeners, the Intersection Observer API provides a modern, efficient way to detect Oct 11, 2019 · I'm trying to track element visibility with React/Hooks and the Intersection Observer API. Dec 13, 2024 · Implementing infinite scrolling can be complex, but with the Intersection Observer API available in JavaScript, the task becomes much simpler and more efficient. MutationObserver is a JavaScript object that observes changes to the DOM and executes callback functions. Jun 24, 2024 · The Intersection Observer API allows us to easily check if two items are intersecting. For the sake of Dec 13, 2024 · The Intersection Observer API provides a way to asynchronously observe changes in the intersection (visible area) of a target element with an ancestor element or the top-level document's viewport. The Intersection Observer API provides a way to asynchronously observe changes in the intersection of a target element with an ancestor element or with a top-level document's viewport. @Directive({ selector: '[appObservable]', }) export class ObservableDirective { private observer: IntersectionObserver; @Output() intersection = new EventEmitter<void>(); Observer link What is an Observer? An Observer is a consumer of values delivered by an Observable. ljh hrtde xqrvbv vnc lgrtam xxvorryh opyojo njjqsa tqnzjn stiqs