Introduction to HTML Components
Personally, I think there's an important lesson here, and its the same lesson that polymer is learning as it stumbles around trying to convince people to use it.<p>Most people don't actually derive much benefit from writing custom UI widget primitives.<p>Certainly, that's a useful thing for a UI toolkit builder to be able to do, but tangibly, for most people, it's not actually useful.<p>I don't have time to invest hours implementing `ImageDropDownSpinner` as a custom element. <select> is good enough for me, and heck, maybe I'll use some 3rd party widget if I need something special.<p>That's not why react, vue, angular, etc. are winning the mind share of 'how to build web apps'; building UI widget is far less interesting than the ability to decompose your UI into a custom hierarchy of re-usable self contained units of functionality, that only at the <i>lowest level</i> actually involve UI components, is extremely powerful.<p>They might look like custom widgets, but <PageFoo> isn't a UI widget, it's your entire application; that's the difference.<p>It's easy to say this was a revolutionary idea, before its time, and it would have flown today instead of vanished into obscurity... but I think it missed the mark; it didn't solve problems people were actually having.<p>...but to be fair, it's easy to look at 'Web Component' efforts (like Polymer...) and go... yeah, this seems very familiar...