Search
Healthcare, Selling Lemons, and the Price of Developer Experience
9.2.2023
Every now and then, a one blog post is published and it spurs a reaction or response in others that are, in turn, published as blogs posts, and a theme starts to emerge. That’s what happened this past week and …
Healthcare, Selling Lemons, and the Price of Developer Experience...
fetch with Timeout
16.1.2023
A few years back I wrote a blog post about how write a fetch Promise that times out. The function was effective but the code wasn’t great, mostly because AbortController , which allows you to cancel a fetch Promise, did not yet exist. With AbortController and AbortSignal available...
Customizing HTML Form Validation
9.1.2023
Form validation has always been my least favorite part of web development. You need to duplicate validation on both client and server sides, handle loads of events, and worry about form element styling. To aid form validation, the HTML spec added some new form attributes like required and pattern...
How to Determine a JavaScript Promise’s Status
3.1.2023
Promises have changed the landscape of JavaScript. Many old APIs have been reincarnated to use Promises (XHR to fetch, Battery API), while new APIs trend toward Promises. Developers can use async/await to handle promises, or then/catch/finally with callbacks, but what Promises don’t tell...
Detect XR Support with JavaScript
2.1.2023
A few years ago I wrote an article about how to detect VR support with JavaScript. Since that time, a whole lot has changed. “Augmented reality” became a thing and terminology has moved to “XR”, instead of VR or AR. As such, the API has needed to evolve. The presence...
Document.elementFromPoint
30.12.2022
Reacting to events with JavaScript is the foundation of a dynamic experiences on the web. Whether it’s a click event or another typical action, responding to that action is important. We started with assigning events to specific elements, then moved to event delegation for efficiency, but...
Detect Browser Bars Visibility with JavaScript
30.12.2022
It’s one thing to know about what’s in the browser document, it’s another to have insight as to the user’s browser itself. We’ve gotten past detecting which browser the user is using, and we’re now into knowing what pieces of the browser UI users are seeing....
JavaScript print Events
30.12.2022
Media queries provide a great way to programmatically change behavior depending on viewing state. We can target styles to device, pixel ratio, screen size, and even print. That said, it’s also nice to have JavaScript events that also allow us to change behavior. Did you know you’re...
How to Control CSS Animations with JavaScript
27.12.2022
When it comes to animations on the web, developers need to measure the animation’s requirements with the right technology — CSS or JavaScript. Many animations are manageable with CSS but JavaScript will always provide more control. With document.getAnimations, however, you can...
Detecting Fonts Ready
26.12.2022
Knowing when resources are loaded is a key part of building functional, elegant websites. We’re used to using the DOMContentLoaded event (commonly referred to as “domready”) but did you know there’s an event that tells you when all fonts have loaded? Let’s learn how...
How to Internationalize Numbers with JavaScript
21.11.2022
Presenting numbers in a readable format takes many forms, from visual charts to simply adding punctuation. Those punctuation, however, are different based on internationalization. Some countries use , for decimal, while others use .. Worried about having to code for all this madness? Don’t...
How to Extend Prototypes with JavaScript
31.10.2022
One of the ideological sticking points of the first JavaScript framework was was extending prototypes vs. wrapping functions. Frameworks like MooTools and Prototype extended prototypes while jQuery and other smaller frameworks did not. Each had their benefits, but ultimately all these years later...
How to Use window.crypto in Node.js
27.10.2022
I’ve been writing a bunch of jest tests recently for libraries that use the underlying window.crypto methods like getRandomValues() and window.crypto.subtle key management methods. One problem I run into is that the window.crypto object isn’t available, so I need to shim it. To use...
Detect System Theme Preference Change Using JavaScript
24.10.2022
JavaScript and CSS allow users to detect the user theme preference with CSS’ prefers-color-scheme media query. It’s standard these days to use that preference to show the dark or light theme on a given website. But what if the user changes their preference while using your app?...
How to Use Storage in Web Extensions
20.10.2022
Working on a web extension is an interesting experience — you get to taste web while working with special extension APIs. One such API is storage — the web extension flavor of persistence. Let’s explore how you can use session and local storage within your Manifest V3...
Skip or Only Run a Test with JavaScript Mocha
10.10.2022
Whenever I start to feel anxiety about a big change I’m making, I start writing more unit tests. I’ll write down my fear and then write a test that attacks, and eventually relaxes, that fear. There are two actions that I’ve been frequently using with test writing: skipping all...
Jaká byla Nordic.js 2022
10.10.2022
Trvalo to tři dlouhé roky, než se mohla odehrát další iterace populárního cyklu severských frontendových konferencí Nordic.js a Nordic.design. Přinášíme reportáž přímo z místa!
Named Element IDs Can Be Referenced as JavaScript Globals
27.9.2022
Did you know that DOM elements with IDs are accessible in JavaScript as global variables? It’s one of those things that’s been around, like, forever but I’m really digging into it for the first time.
If this is the first …
Named Element IDs Can Be Referenced as JavaScript Globals originally...
Monitor Events and Function Calls via Console
29.8.2022
Despite having worked on the very complex Firefox for a number of years, I’ll always love plain old console.log debugging. Logging can provide an audit trail as events happen and text you can share with others. Did you know that chrome provides monitorEvents and monitor so that you can get...
Specify Node Versions with .nvmrc
9.8.2022
I’ve heavily promoted nvm, a Node.js version manager, over the years. Having a tool to manage multiple versions of a language interpreter has been so useful, especially due to the complexity of Node.js package management. One tip I like to give new developers is adding a .nvmrc file to their...