Category Archives: davidwalsh

Resize Observer

Creating websites that are reactive and responsive used to be considered advanced but responsiveness is a necessity for successful websites and apps. We’ve added media queries, matchMedia, and a host of other APIs to help developers make responsiveness easier and now we get a new one: ResizeObserver. With the Resize Observer API, we can watch for resizing on individual elements!

read more

AI-Backed Image Background Removal (Sponsored)

I’ve worked on dozens of eCommerce sites in my career and many of them were hamstrung by the same pain points: tax collection, payment customization, and image optimization. While tax collection and payment customization were important, image optimization was always the hardest and most important problem to solve: no one wants to buy a product whose imagery looked amateur. When you couple the need for good imagery with clients wanting to upload their own images…you have a real problem.

Instead of painfully explaining to clients how to take quality pictures, or even more painfully explain that there was no magic way to make their images look amazing, I wish I had Cloudinary’s newest feature: AI-backed image background removal. With AI-backed background removal, you can upload images to Cloudinary and let them do the hard work!

Uploading Photos

Cloudinary provides numerous methods for uploading photos: remote fetch, administration panel, or an API for which they provide helpers in a variety of programming languages and frameworks:

// npm install cloudinary
var cloudinary = require('cloudinary');

// Set your API information
	cloud_name: 'david-walsh-blog',
	api_key: '############',
	api_secret: '############'

// Upload an image, 
cloudinary.uploader.upload('sample-photos/my-photo.jpg', function(result) {
    // Log out the result to get the URL of the image

    // Image url is: result.url / result.secure_url
}, {
    public_id: "my-photo",
    // Use preset to automatically remove background
    upload_preset: "remove_background",
    // ...or use the specific setting for it:
    background_removal: "cloudinary_ai"

read more

Recursive Array.flat

There was much talk about Array.prototype.flat during its early stages, starting with the name alone. Many developers preferred the name flatten but the spec differed from MooTools’ implementation. MooTools would recursively flatten an array but the new, official flat implementation defaults one level of flattening,.

The current implementation of Array.prototype.flat is:

[1, 2, [3], [[4]]].flat(/* depth */);
// [1,2,3,[4]]

.flat only flattens arrays to one level by default, but what if you want a truly flattened array? You can use Infinity and flat‘s depth argument to make that happen:

read more

Using Array reduce

Every developer who specializes in any programming language will tell you there’s a powerful tool the language provides that they rarely use and wish they knew more about. For me, it’s Array.prototype.reduce. I quite enjoy the other Array methods like map, filter, and find, but reduce is one that I knew was powerful but never really had much use for.

It wasn’t until I was refactoring some of the Firefox DevTools Debugger code that I found a great use case for reduce — one I plan on using in the future.

Methods like forEach and map were created to avoid side effects, and reduce is no exception. In this case, however, reduce can return an Object other than an Array. Take this case for example:

// Samples sources
const sources = [
    id: "server1.conn13.child1/39",
    url: ""
    id: "server1.conn13.child1/37",
    url: ""

// Return an object of sources with the keys being "id"
const sourcesMap = sources.reduce((map, source) => {
  map[] = source
  return map;
}, {});

In the example above, we take an array of Source objects and return a single object literal with each Source‘s id as the key:

  "server1.conn13.child1/39": {
    "id": "server1.conn13.child1/39",
    "url": ""
  "server1.conn13.child1/37": {
    "id": "server1.conn13.child1/37",
    "url": ""

read more