All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.
Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.
elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent
The package that linked you here is now pure ESM. It cannot be require()'d from CommonJS.
This means you have the following choices:
import foo from 'foo' instead of const foo = require('foo') to import the package. You also need to put "type": "module" in your package.json and more. Follow the below guide.await import(…) from CommonJS instead of require(…).
React recently introduced an experimental profiler API. This page gives instructions on how to use this API in a production release of your app.
Table of Contents
React DOM automatically supports profiling in development mode for v16.5+, but since profiling adds some small additional overhead it is opt-in for production mode. This gist explains how to opt-in.
React recently introduced an experimental profiler API. After discussing this API with several teams at Facebook, one common piece of feedback was that the performance information would be more useful if it could be associated with the events that caused the application to render (e.g. button click, XHR response). Tracing these events (or "interactions") would enable more powerful tooling to be built around the timing information, capable of answering questions like "What caused this really slow commit?" or "How long does it typically take for this interaction to update the DOM?".
With version 16.4.3, React added experimental support for this tracing by way of a new NPM package, scheduler. However the public API for this package is not yet finalized and will likely change with upcoming minor releases, so it should be used with caution.
| namespace Analogy | |
| { | |
| /// <summary> | |
| /// This example shows that a library that needs access to target .NET Standard 1.3 | |
| /// can only access APIs available in that .NET Standard. Even though similar the APIs exist on .NET | |
| /// Framework 4.5, it implements a version of .NET Standard that isn't compatible with the library. | |
| /// </summary>INetCoreApp10 | |
| class Example1 | |
| { | |
| public void Net45Application(INetFramework45 platform) |
| let cache = new Map(); | |
| let pending = new Map(); | |
| function fetchTextSync(url) { | |
| if (cache.has(url)) { | |
| return cache.get(url); | |
| } | |
| if (pending.has(url)) { | |
| throw pending.get(url); | |
| } |
UPDATE (Fall 2020): This gist is an updated version to the Windows 10 Fall Creators Update - Installing Node.js on Windows Subsystem for Linux (WSL) guide, I usually just keep here notes, configuration or short guides for personal use, it was nice to know it also helps other ppl, I hope this one too.
Windows updated windows subsystem for linux to version 2, as the F.A.Q stated you can still use WSL version 1 side by side with version 2. I'm not sure about existing WSL machines surviving the upgrade process, but as always backup and 🤞. NOTE: WSL version 1 is not replace/deprecated, and there ar
Sarah Lim, Northwestern University
Update, September 2019: This Gist detailed an early idea which formed the basis for a major research project. For more information, you can read the resulting full paper, which received Best Paper Honorable Mention at UIST 2018. A tool based on this research is now available on Firefox Nightly.
Hidden dependencies between CSS properties are a common source of beginner confusion. For instance, a user might write the following code in order to vertically align some text within a <div>:
