Updated article link to the github repo, which points to the website. Since the GH link is more likely to be the most desired entry point by users of this site.
Note: I'm not the one who down-voted this.
Cassandra and Redis aren't really document databases. Cassandra is closer to BigTable as a column store, and Redis is more like an extended key/value store.
I'm generally skeptical of posts for "courses" on this and similar sites. In particular, at a glance, I don't know if this is a really free site, if some courses are free, or you can complete the lessons with or without payment. I don't have a problem with people wanting to get paid, but one really needs to be skeptical, there's a lot of junk.
Also, as MaxArt mentions, v5 is a few versions behind, but Angular had had far fewer breaking changes between versions since v3-4. The workflows are pretty solid.
I'm personally not a fan of Angular and prefer React+Redux+thunks/fetch myself YMMV but every time I've used or worked with Angular, I'm reminded of why I don't care for it.
It's not a bad article, but necessarily a little shallow. Also, I tend to prefer JSX over Vue's component model, but that's me. To me, JSX as used is very similar to what E4X offered over a decade ago, but never bore fruit. Only Mozilla's JS engine and Adobe's ActionScript ever supported it . VB.Net also has a similar feature for XML literals that I wish C# integrated.
In the end it's important to have at least a shallow understanding of the concepts as they make building actual applications much easier in practice. Though, like anything, you can use any programming tool badly and create a mess.
First, I'm not sure something like this should even be 38kb, it just feels incredibly oversized for what it is. I am glad they switched to rollup in the past. I'm also unsure what is actually needed from the polyfills.
Overall, it's just a large library for what it does and could probably be hand-crafted for under 5kb uglified.
(note: I'm not the one who downvoted)
I tend to prefer more functional approaches to work in JS... keeping libraries separated from context and data object instances. I'm not a fan of OOP in general, and feel it leads to confusing spaghetti code.
Most of the examples would be easier to reason with using simpler objects, workflow functions and maybe something like IxJS as needed.
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NOTE: iirc, the downvote wasn't me.