Whenever we send or retrieve information with JavaScript, we initiate a thing known as an Ajax call. Ajax is a technique to send and retrieve information behind the scenes without needing to refresh the page. It allows browsers to send and retrieve information, then do things with what it gets back, like add or change HTML on the page.
Let's take a look at the history of that and then bring ourselves up-to-date.
One of the big reasons to use jQuery, for a long time, was how easy it made Ajax. It has a super clean, flexible, and cross-browser compatible API for all the Ajax methods. jQuery is still mega popular, but it's becoming more and more common to ditch it, especially as older browser share drops and new browsers have a lot of powerful stuff we used to learn on jQuery for. Even just querySelectorAll is often cited as a reason to lose the jQuery dependency.
How's Ajax doing?
I’ve been playing around with ServiceWorker a lot recently, so when Chris asked me to write an article about it I couldn’t have been more thrilled. ServiceWorker is the most impactful modern web technology since Ajax. It’s an API that lives inside the browser and sits between your web pages and your application servers. Once installed and activated, a ServiceWorker can programmatically determine how to respond to requests for resources from your origin, even when the browser is offline. ServiceWorker can be used to power the so-called "Offline First" web.
ServiceWorker is a progressive technology, and in this article, I'll show you how to take a website and make it available offline for humans who are using a modern browser while leaving humans with unsupported browsers unaffected.