Those two code examples are different because that's the tradeoff that Solid made. It allows Solid to track changes in a uniform way even if the data isn't inside a component. Because in Solid components are just a way to organize code, not a unit of rendering (like in React).
And on top of that if you think that React still somehow has unidirectional data flow, it doesn't. Hooks make it anything but unidirectional. And not that different from signals: https://res.cloudinary.com/practicaldev/image/fetch/s--upMC6... But often less predictable.
Dan Abramov replied to those as well. Personally, the purity of the React model with bringing in only local rather than global state in every function is what appeals to me. Even hooks are still local state, if you change the value in useState, you're not going to suddenly have something change elsewhere, where it wasn't explicit where you changed it.
useEffect, useContext, and usSyncExternalStore are no longer about "local only".
And you never use only local state. You advocate for Redux in a different comment which is literally a global state where you are going to have something suddenly change somewhere from the point of view of a component.
You are misunderstanding me. I never said to use only local state with no global state at all. My point is that signals automatically make all state global because you can reference what should be a local value in a component, in another component entirely which is not at all connected to the initial component either in a parent or a child relationship. In other words, you are making a graph, not a tree.
For Redux, at least that's explicit, for signals, it's really not.
- The Evolution of Signals in JavaScript, https://dev.to/this-is-learning/the-evolution-of-signals-in-...
- React vs Signals: 10 Years Later, https://dev.to/this-is-learning/react-vs-signals-10-years-la...
- Making the Case for Signals in JavaScript , https://dev.to/this-is-learning/making-the-case-for-signals-...
Those two code examples are different because that's the tradeoff that Solid made. It allows Solid to track changes in a uniform way even if the data isn't inside a component. Because in Solid components are just a way to organize code, not a unit of rendering (like in React).
And on top of that if you think that React still somehow has unidirectional data flow, it doesn't. Hooks make it anything but unidirectional. And not that different from signals: https://res.cloudinary.com/practicaldev/image/fetch/s--upMC6... But often less predictable.
See also The Cost of Consistency in UI Frameworks, https://dev.to/this-is-learning/the-cost-of-consistency-in-u... which is slightly related to this.