Coder Social home page Coder Social logo

Comments (3)

rickhanlonii avatar rickhanlonii commented on April 25, 2024 1

Is it really possible that useEffect with empty array can be called twice with reserving the component state in concurrent mode? (Without the offscreen API)?

Yes, this happens today with Fast Refresh. And it also happens today with layout effects when you re-suspend a tree on update. In that case we move the existing content "offscreen" (unmounting the layout effects), and when the content is ready to commit again re-mount it using the same state and re-creating the layout effects. This is important for performance of re-committing suspended trees (so we don't need to destroy and re-create all of the state like DOM elements). Since the content may have changed, it means we need to re-run layout side-effects, like setting the hight of a tooltip, so it's not out of date.

Even outside of these cases, if you don't clean up the resources like websockets or subscriptions during unmount, then you'll leak resources or connections, with Strict Mode helps you find (as described in the docs for this behavior here).

from react.

Szymon20000 avatar Szymon20000 commented on April 25, 2024 1

@rickhanlonii Thanks for taking the time and responding!

from react.

zhangshichun avatar zhangshichun commented on April 25, 2024


from react.

Related Issues (20)

Recommend Projects

  • React photo React

    A declarative, efficient, and flexible JavaScript library for building user interfaces.

  • Vue.js photo Vue.js

    🖖 Vue.js is a progressive, incrementally-adoptable JavaScript framework for building UI on the web.

  • Typescript photo Typescript

    TypeScript is a superset of JavaScript that compiles to clean JavaScript output.

  • TensorFlow photo TensorFlow

    An Open Source Machine Learning Framework for Everyone

  • Django photo Django

    The Web framework for perfectionists with deadlines.

  • D3 photo D3

    Bring data to life with SVG, Canvas and HTML. 📊📈🎉

Recommend Topics

  • javascript

    JavaScript (JS) is a lightweight interpreted programming language with first-class functions.

  • web

    Some thing interesting about web. New door for the world.

  • server

    A server is a program made to process requests and deliver data to clients.

  • Machine learning

    Machine learning is a way of modeling and interpreting data that allows a piece of software to respond intelligently.

  • Game

    Some thing interesting about game, make everyone happy.

Recommend Org

  • Facebook photo Facebook

    We are working to build community through open source technology. NB: members must have two-factor auth.

  • Microsoft photo Microsoft

    Open source projects and samples from Microsoft.

  • Google photo Google

    Google ❤️ Open Source for everyone.

  • D3 photo D3

    Data-Driven Documents codes.