In addition to JSONata, there's another very important project that is technically not part of core Node-RED. But it is rare to see one without another, and I'm speaking of the Node-RED Dashboard add-on module.

Every single Node-RED project I've seen makes use of the Dashboard module to build a HTML-based user interface. Which was why when I started learning Node-RED tutorials I was confused there were no mention of how to build an user interface. It took some time before I realized the Dashboard is not considered part of the core system and had to be installed separately. Once installed, there were additional nodes representing UI and additional editor interface. (Some UI to build UI...)

Once I finally realized my misconception and corrected it, I was able to build a functional interface in less than ten minutes, an amazingly short time for getting up and running under a new user interface construction system. Basic input controls like buttons and sliders, basic output controls like gauges and charts, they all worked just by connecting nodes to feed data.

However, the layout options are fairly limited. While it is extremely easy to build something closely resembling what I had in mind, I see no way to precisely adjust layout details. The rest of Node-RED reminds me of snapping LEGO pieces together, but the Dashboard exemplified the feeling: I can quickly snap together something that resembles the shape I had in mind, but if a distance is not an even number of LEGO stud spacing, I'm flat out of luck.

But even if I don't see options for custom layout, I found instructions for building my own display widgets. Node-RED Dashboard is built on AngularJS a.k.a. Angular 1.x. I'm not sure I want to invest the time to learn AngularJS now. I can probably pick up enough AngularJS to do a custom widget if all I want is that single widget and reuse everything else. But AngularJS is currently on long-term support status receiving only security updates. Fortunately the fact Node-RED Dashboard is an add-on means people can (and have) built their own dashboard using other UI frameworks by hooking into the same extensibility mechanisms used by Dashboard. So if I want precise control over layout or other custom mechanism, I can do that while still using Node-RED as the underlying engine. I'm impressed we have that extremely powerful option.

But those dreams of grand expansion and customization are for the future. Right now I still need to build experience working with the system, which means putting it to work on a simple test project.