Why does my localhost application on Node.js take so long/refuse to connect?

Why does my localhost:3000 application take so long to load? I have tried quite a lot of ways to solve this, such as: Disable IPv6 Add localhost into the hosts file Update npm and node.js to the …

Javascript / Vue JS – Retrieve value of all elements in object

I have an object that retrieves 4 different elements with different numerical values. I’m trying to access and retrieve all these numerical values. The object returns the following: {__ob__: Observer} …

Difference when comparing the timing results of performance API and chrome’s developer tools

I am trying to time a fetch call. The following screenshot shows the time chrome developer tools show for a particular fetch request. As could be seen for the request marked in red color, total time …

Performances of ‘lineTo’ method when going beyond canvas dimensions

Using a canvas context, assuming I call beginPath then twice lineTo with x=-999, y=-999 and x=50, y=50 then finally stroke, it will draw a line from the top-left corner to the (50,50) point. During …

React-konva slow drag performance with large number of lines rendered

I have problem with dragging functionality while having large number of rendered lines in React-konva. Currently I am mapping over Array.apply(null, Array(10000)) to render lines horizontally. However,…

How can I fix this button

When I click on any button it shows same first button output. How can I fix it. I want it be different when I click on different button it should display same output that button has. I want it to be …

PerformanceResourceTiming.responseStart and PerformanceResourceTiming.requestStart both are 0 for a status ok http request

I want to measure TTFB (Time to First Byte) for an HTTP request. I’ve hosted a 0KB pdf file on an amazon S3 server, and I’m using the fetch api to get it. Here’s my code: let url = “https://s3-us-…

How can I most easily identify bottlenecks in React render performance?

I’m having an issue with identifying bottlenecks in render performance while working on a JSON viewer. With few elements, it performs well, but at a certain point it becomes annoyingly slow. Checking the profiler, it seems that elements are rendering fast enough, but I’ve noticed a few issues that I’m not sure how to pursue. Overview The app is a JSON viewer which allows you to expand / minimize all elements at once, as well as individual elements. Performance is fine with few elements, but seems to decrease dramatically as the number of elements increases. When profiling both my object

Question about code execution and the nature of javascript blocking/ non blocking

Basically I have something similar to the code below and I’m not entirely sure what order of execution is always going to happen. Right now I suppose it executes in a non blocking fashion, being But I’ve had times that it’s I have no control over when res.on(‘data’) is called because it is a socket event listener and is handled on a separate server. I guess that I’m afraid that the callback is going to be called in the middle of res.on() is that something that could happen? Say res.on() is right in the middle of execution would the callback

value of using React.forwardRef vs custom ref prop

I see that React.forwardRef seems to be the sanctioned way of passing a ref to a child functional component, from the react docs: However, what is the advantage of doing this over simply passing a custom prop?: The only advantage I can think of is maybe having a consistent api for refs, but is there any other advantage? Does passing a custom prop affect diffing when it comes to rendering and cause additional renders, surely not as the ref is stored as mutable state in the current field? Say for example you wanted to pass multiple refs (which tbh, might