FileMaker developers (you) have invested a lot of time into learning FileMaker. After all, they (you) spend most of your time in that platform. You need to know all about schema, security, data types, functions, and so on. There's so much already to know.
FileMaker developers can feel overwhelmed about what's in the JS language. FileMaker developers feel like they have to learn all of the langauage to have any chance of being able to use it in FileMaker.
Luckily that isn't the case. With just a little bit of time, study, and the correct path, you can learn what in the JS langauge will help you right away build great solutions to problems.
Blazing the trail
I went through this a few years ago. I started studying the entire langauge. But as I did more and more JS I realized that I was using the same JS over and over. This began the creation of the JS Learning Path.
Using what we know
Making this even eaiser is the fact that FileMaker developers (you) already know a lot about programming since we work with FileMaker. We know about schema, functions, scripting, variables, scope, and so on. You're not coming to this from nothing.
Here's the learning path in visual form:
It's a bit hard to read, so I'll break it down here in textual form.
We will spend lots of time taking data from FileMaker and turning it into something the JS library can use. So we need to learn how to manipulate data. The data could be strings, arrays, or objects. So we need to explore that in JS which manipulates the data.
It's essential to get data from FileMaker into the web viewer, so let's explore how to do that and how to make the data ready for the JS library.
Update the web viewer
We also need to explore how to update the web viewer with new or revised data from FileMaker.
We will need to know a bit about how to structure HTML so that we can build the widgets appropriately.
We will need to explore some CSS: some styling.