observer some element and if it is visible, do something
React MutateObserver Component
Monitor if a component is inside the viewport, using IntersectionObserver API
Resize observer for React
A React hook that allows you to use a ResizeObserver to measure an element's size.
Resize observer for React
🏯 PositionObserver is a JavaScript tool that provides a way to asynchronously observe changes in the position of a target element within its viewport.
Polyfills the ResizeObserver API and supports box size options from the latest spec
React hook to use IntersectionObserver declaratively.
Reactive primitives for observing resizing of HTML elements.
A polyfill for the Resize Observer API
A React hook for the IntersectionObserver API that uses a polyfill when the native API is not available
A React hook that fires a callback whenever ResizeObserver detects a change to its size
Detect if web fonts are available
Tracks the intersection of a DOM element and its containing element or the viewport.
An implementation and polyfill of the Resize Observer draft.
Observe CSS property changes on any elements
@vue/reactivity
A React Hooks package for mutation-observer
A simple little class that helps making Observable testing a breeze
TypeScript definitions for resize-observer-browser
React bindings for MobX. Create fully reactive components.
An Implementation of ES Observables
React hook to detect if web fonts are available 🪝
This is an alternative implementation of the observer pattern. As you may know, Ruby (and Rails/ActiveRecord) already have an implementation of it. This implementation is a variation of the pattern, so it is not supposed to supersede the existing implementations, but "complete" them for the specific use-cases addressed.
Project Simulator (in development) aims to make it easier to observe triggers and actions from an XML based model.
ReactiveCocoa is an amazing system, and RubyMotion could benefit from the lessons learned there! Motion-Wiretap is, essentially, a wrapper for Key-Value coding and observation. It exposes a +Wiretap+ class that you can use as a signal, or add listeners to it. Extensions are provided to listen to an +Array+ of +Wiretap+ objects, and the `UIKit`/`AppKit` classes are augmented to provide actions as events (gestures, mouse events, value changes).