Rob Gravelle

Back in the early days of the World Wide Web, there were many web designers who built websites for people and organizations. I was one for a while. Since then, web designers have largely evolved into web developers, spurred by the emergence of mobile applications and an ever-more interactive online experience. As a result, many […]

Finding and replacing text is one of the oldest and most common tasks in programming, yet, it can still trip up novice and experienced coders alike. As a web developer, you are probably already familiar with JavaScript’s replace() function. I thought I was too, until I had to use it recently. I soon found out […]

In the recent Asynchronous Processing in ES6  web development tutorial, we learned one way to process several asynchronous calls in a row using the static Promise.all() method. It combines an iterable of promises into a single promise that provides the amalgamated results as a single array. Since that article was published, several people have asked […]

A short while ago, in May of 2021, I wrote about Luxon’s status as heir apparent to Moment.js as the later went into maintenance mode. Since then, creators of plugins for Moment.js have been scrambling to migrate their libraries to Luxon, as more and more organizations adopt it as their de facto JS Date library. […]

Part 1: Persisting Selected Nodes If you look for them, you WIll find tree structures all over the place – from nature, to cities and their neighborhoods, to your own family’s genealogy (i.e., your family tree). Unsurprisingly, trees crop up just as often in programmatic data structures; for instance, in the Document Object Model (DOM): […]

Part 2: Loading Saved Nodes Welcome to the second and final installment of this web development tutorial series on Recursive Tree Node Processing. In part one, we wrote code to save vehicle manufacturer, model, and level selections from the VehicleNode tree. The save operation entailed the creation of a simplified tree by whittling it down […]

Error handling plays an essential part in just about any application, doubly so when dealing with network calls. For that reason, libraries like RxJS include a wide variety of mechanisms for dealing with errors of every conceivable sort in a graceful way. In fact, RxJS lends itself to so many error handling strategies that developers […]

With the abundance of Promises, Observables, and setTimeouts in modern JavaScript applications, it is imperative that developers understand how to work with asynchronous processes. Async calls all share one thing in common, and that is that they require waiting for a method to complete before continuing on. In this article, web developers will learn how […]

The Angular Material Tree, the MatTree, is the ideal control for displaying hierarchical data. Not only can it represent a variable number of levels, but each item in the tree can possess a different number of children and levels. In the 2nd installment of the Create a Nested Multi-select Tree with in Angular series, we […]

Thanks to directives like ngClass and ngStyle, it’s almost always possible to style text without resorting to setting CSS properties in TypeScript code as in: document.getElementById(“p2”).style.color = “blue”; Nonetheless, there are times when some scripting code will be required in order to determine which class(es) or style(s) need to be activated under a specific condition. […]

As the name suggests, the primary purpose of Angular Route Guards is to guard access to a certain route, such as an authenticated area of your app, or an admin section that requires special permissions to be accessed. Once admission to a route has been blocked, the next step is often to redirect the user […]

Working in the realm of data visualization, as I do, you soon learn that many charts and graphics entail some sort of temporal element. For example, take this chart:   Basic as it may be, as far as charts go, generating readable ticks, labels, tooltips, legends, and other text for many different locales takes a […]